* Fix a livelock in dax_layout_busy_page() present since v4.18. The
lockup triggers when truncating an actively mapped huge page out of a
mapping pinned for direct-I/O.
* Fix mprotect() clobbers of _PAGE_DEVMAP. Broken since v4.5 mprotect()
clears this flag that is needed to communicate the liveness of device
pages to the get_user_pages() path.
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Merge tag 'libnvdimm-fixes-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Dan writes:
"libnvdimm/dax 4.19-rc8
* Fix a livelock in dax_layout_busy_page() present since v4.18. The
lockup triggers when truncating an actively mapped huge page out of
a mapping pinned for direct-I/O.
* Fix mprotect() clobbers of _PAGE_DEVMAP. Broken since v4.5
mprotect() clears this flag that is needed to communicate the
liveness of device pages to the get_user_pages() path."
* tag 'libnvdimm-fixes-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
mm: Preserve _PAGE_DEVMAP across mprotect() calls
filesystem-dax: Fix dax_layout_busy_page() livelock
Other arches have ioremap_wt() to map IO areas write-through.
Implement it on PPC as well in order to avoid drivers using
__ioremap(_PAGE_WRITETHRU)
Also implement ioremap_coherent() to avoid drivers using
__ioremap(_PAGE_COHERENT)
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Live Partition Migrations require all the present CPUs to execute the
H_JOIN call, and hence rtas_ibm_suspend_me() onlines any offline CPUs
before initiating the migration for this purpose.
The commit 85a88cabad
("powerpc/pseries: Disable CPU hotplug across migrations")
disables any CPU-hotplug operations once all the offline CPUs are
brought online to prevent any further state change. Once the
CPU-Hotplug operation is disabled, the code assumes that all the CPUs
are online.
However, there is a minor window in rtas_ibm_suspend_me() between
onlining the offline CPUs and disabling CPU-Hotplug when a concurrent
CPU-offline operations initiated by the userspace can succeed thereby
nullifying the the aformentioned assumption. In this unlikely case
these offlined CPUs will not call H_JOIN, resulting in a system hang.
Fix this by verifying that all the present CPUs are actually online
after CPU-Hotplug has been disabled, failing which we restore the
state of the offline CPUs in rtas_ibm_suspend_me() and return an
-EBUSY.
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently on POWER9 SMT8 cores systems, in sysfs, we report the
shared_cache_map for L1 caches (both data and instruction) to be the
cpu-ids of the threads in SMT8 cores. This is incorrect since on
POWER9 SMT8 cores there are two groups of threads, each of which
shares its own L1 cache.
This patch addresses this by reporting the shared_cpu_map correctly in
sysfs for L1 caches.
Before the patch
/sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_map : 000000ff
/sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_map : 000000ff
/sys/devices/system/cpu/cpu1/cache/index0/shared_cpu_map : 000000ff
/sys/devices/system/cpu/cpu1/cache/index1/shared_cpu_map : 000000ff
After the patch
/sys/devices/system/cpu/cpu0/cache/index0/shared_cpu_map : 00000055
/sys/devices/system/cpu/cpu0/cache/index1/shared_cpu_map : 00000055
/sys/devices/system/cpu/cpu1/cache/index0/shared_cpu_map : 000000aa
/sys/devices/system/cpu/cpu1/cache/index1/shared_cpu_map : 000000aa
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 SMT8 cores consist of two groups of threads, where threads in
each group shares L1-cache. The scheduler is not aware of this
distinction as the current sched-domain hierarchy has all the threads
of the core defined at the SMT domain.
SMT [Thread siblings of the SMT8 core]
DIE [CPUs in the same die]
NUMA [All the CPUs in the system]
Due to this, we can observe run-to-run variance when we run a
multi-threaded benchmark bound to a single core based on how the
scheduler spreads the software threads across the two groups in the
core.
We fix this in this patch by defining each group of threads which
share L1-cache to be the SMT level. The group of threads in the SMT8
core is defined to be the CACHE level. The sched-domain hierarchy
after this patch will be :
SMT [Thread siblings in the core that share L1 cache]
CACHE [Thread siblings that are in the SMT8 core]
DIE [CPUs in the same die]
NUMA [All the CPUs in the system]
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On IBM POWER9, the device tree exposes a property array identifed by
"ibm,thread-groups" which will indicate which groups of threads share
a particular set of resources.
As of today we only have one form of grouping identifying the group of
threads in the core that share the L1 cache, translation cache and
instruction data flow.
This patch adds helper functions to parse the contents of
"ibm,thread-groups" and populate a per-cpu variable to cache
information about siblings of each CPU that share the L1, traslation
cache and instruction data-flow.
It also defines a new global variable named "has_big_cores" which
indicates if the cores on this configuration have multiple groups of
threads that share L1 cache.
For each online CPU, it maintains a cpu_smallcore_mask, which
indicates the online siblings which share the L1-cache with it.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If GCC is not built with glibc support then we must explicitly tell it
which register to use for TLS mode stack protector, otherwise it will
error out and the cc-option check will fail.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 6c1719942e ("powerpc/of: Remove useless register save/restore
when calling OF back") removed the saving of srr0 and srr1 when calling
into OpenFirmware. Commit e31aa453bb ("powerpc: Use LOAD_REG_IMMEDIATE
only for constants on 64-bit") did the same for rtas.
This means we don't need to save the extra stack space and can use
the common SWITCH_FRAME_SIZE.
There were already no users of _SRR0 and _SRR1 so we can remove them
too.
Link: https://github.com/linuxppc/linux/issues/83
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The powerpc mobility code may receive RTAS requests to perform PRRN
(Platform Resource Reassignment Notification) topology changes at any
time, including during LPAR migration operations.
In some configurations where the affinity of CPUs or memory is being
changed on that platform, the PRRN requests may apply or refer to
outdated information prior to the complete update of the device-tree.
This patch changes the duration for which topology updates are
suppressed during LPAR migrations from just the rtas_ibm_suspend_me()
/ 'ibm,suspend-me' call(s) to cover the entire migration_store()
operation to allow all changes to the device-tree to be applied prior
to accepting and applying any PRRN requests.
For tracking purposes, pr_info notices are added to the functions
start_topology_update() and stop_topology_update() of 'numa.c'.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Ever since commit 15a3204d24 ("powerpc/64s: Set assembler machine type
to POWER4") we force -mpower4 to be passed to the assembler
irrespective of the CFLAGS used (for Book3s 64).
When building a powerpc64 kernel with clang, clang will not add -many
to the assembler flags, so any instructions that the compiler has
generated that are not available on power4 will cause an error:
/usr/bin/as -a64 -mppc64 -mlittle-endian -mpower8 \
-I ./arch/powerpc/include -I ./arch/powerpc/include/generated \
-I ./include -I ./arch/powerpc/include/uapi \
-I ./arch/powerpc/include/generated/uapi -I ./include/uapi \
-I ./include/generated/uapi -I arch/powerpc -I arch/powerpc \
-maltivec -mpower4 -o init/do_mounts.o /tmp/do_mounts-3b0a3d.s
/tmp/do_mounts-51ce54.s:748: Error: unrecognized opcode: `isel'
GCC does include -many, so the GCC driven gas call will succeed:
as -v -I ./arch/powerpc/include -I ./arch/powerpc/include/generated -I
./include -I ./arch/powerpc/include/uapi
-I ./arch/powerpc/include/generated/uapi -I ./include/uapi
-I ./include/generated/uapi -I arch/powerpc -I arch/powerpc
-a64 -mpower8 -many -mlittle -maltivec -mpower4 -o init/do_mounts.o
Note that isel is power7 and above for IBM CPUs. GCC only generates it
for Power9 and above, but the above test was run against the clang
generated assembly.
Peter Bergner explains:
When using -many -mpower4, gas will first try and find a matching
power4 mnemonic and failing that, it will then allow any valid
mnemonic that gas knows about. GCC's use of -many predates me
though.
IIRC, Alan looked at trying to remove it, but I forget why he
didn't. Could be either a gcc or gas issue at the time. I'm not sure
whether issue still exists or not. He and I have modified how gas
works internally a fair amount since he tried removing gcc use of
-many.
I will also note that when using -many, gas will choose the first
mnemonic that matches in the mnemonic table and we have (mostly)
sorted the table so that server mnemonics show up earlier in the
table than other mnemonics, so they'll be seen/chosen first.
By explicitly setting -many we can build with Clang and GCC while
retaining the -mpower4 option.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The variable 'aa_index' is defined as an unsigned value in
update_lmb_associativity_index(), but find_aa_index() may return -1
when dlpar_clone_property() fails. So change find_aa_index() to return
a bool, which indicates whether 'aa_index' was found or not.
Fixes: c05a5a4096 ("powerpc/pseries: Dynamic add entires to associativity lookup array")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Nathan Fontenot nfont@linux.vnet.ibm.com>
[mpe: Tweak changelog, rename is_found to just found]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rather than mixing "if (state)" blocks and gotos, convert entirely to
"if (state)" blocks to make the state machine behaviour clearer.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The wait_state member of eeh_ops does not need to be platform
dependent; it's just logic around eeh_ops.get_state(). Therefore,
merge the two (slightly different!) platform versions into a new
function, eeh_wait_state() and remove the eeh_ops member.
While doing this, also correct:
* The wait logic, so that it never waits longer than max_wait.
* The wait logic, so that it never waits less than
EEH_STATE_MIN_WAIT_TIME.
* One call site where the result is treated like a bit field before
it's checked for negative error values.
* In pseries_eeh_get_state(), rename the "state" parameter to "delay"
because that's what it is.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, eeh_pe_state_mark() marks a PE (and it's children) with a
state and then performs additional processing if that state included
EEH_PE_ISOLATED.
The state parameter is always a constant at the call site, so
rearrange eeh_pe_state_mark() into two functions and just call the
appropriate one at each site.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The function eeh_pe_state_mark_with_cfg() just performs the work of
eeh_pe_state_mark() and then, conditionally, the work of
eeh_pe_state_clear(). However it is only ever called with a constant
state such that the condition is always true, so replace it by direct
calls.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the call to eeh_dev_to_pe() up, so that later it's clear that
"pe" isn't NULL.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Change the name of the fields in eeh_rmv_data to clarify their usage.
Change "edev_list" to "removed_vf_list" because it does not contain
generic edevs, but rather only edevs that contain virtual functions
(which need to be removed during recovery).
Similarly, change "removed" to "removed_dev_count" because it is a
count of any removed devices, not just those in the above list.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Instances of struct eeh_pe are placed in a tree structure using the
fields "child_list" and "child", so place these next to each other
in the definition.
The field "child" is a list entry, so remove the unnecessary and
misleading use of the list initializer, LIST_HEAD(), on it.
The eeh_dev struct contains two list entry fields, called "list" and
"rmv_list". Rename them to "entry" and "rmv_entry" and, as above, stop
initializing them with LIST_HEAD().
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove the unnecessary cast through void * on the first parameter and
remove the unused second parameter (always NULL).
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The 'bus' member of struct eeh_dev is assigned to once but never used,
so remove it.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently a flag, EEH_POSTPONED_PROBE, is used to prevent an incorrect
message "EEH: No capable adapters found" from being displayed during
the boot of powernv systems.
It is necessary because, on powernv, the call to eeh_probe_devices()
made from eeh_init() is too early and EEH can't yet be enabled. A
second call is made later from eeh_pnv_post_init(), which succeeds.
(On pseries, the first call succeeds because PCI devices are set up
early enough and no second call is made.)
This can be simplified by moving the early call to eeh_probe_devices()
from eeh_init() (where it's seen by both platforms) to
pSeries_final_fixup(), so that each platform only calls
eeh_probe_devices() once, at a point where it can succeed.
This is slightly later in the boot sequence, but but still early
enough and it is now in the same place in the sequence for both
platforms (the pcibios_fixup hook).
The display of the message can be cleaned up as well, by moving it
into eeh_probe_devices().
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
eeh_add_to_parent_pe() sometimes removes the EEH_PE_KEEP flag, but it
incorrectly removes it from pe->type, instead of pe->state.
However, rather than clearing it from the correct field, remove it.
Inspection of the code shows that it can't ever have had any effect
(even if it had been cleared from the correct field), because the
field is never tested after it is cleared by the statement in
question.
The clear statement was added by commit 807a827d4e ("powerpc/eeh:
Keep PE during hotplug"), but it didn't explain why it was necessary.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If a device is removed during EEH processing (either by a driver's
handler or as part of recovery), it can lead to a null dereference
in eeh_pe_report_edev().
To handle this, skip devices that have been removed.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If an error occurs during an unplug operation, it's possible for
eeh_dump_dev_log() to be called when edev->pdn is null, which
currently leads to dereferencing a null pointer.
Handle this by skipping the error log for those devices.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The boot wrapper is currently built with -Os. By building with O2 we
can meaningfully reduce the time decompressing the kernel.
I tested by comparing 10 runs of each option in Qemu and on hardware.
The kernel is compressed with KERNEL_XZ built with GCC 8.2.0-7ubuntu1.
The values are counts of the timebase.
Qemu TCG powernv Power8:
Os O2 O3
median 10221123889 6201518438 6568186825
stddev 1361267211 429090641 657930076
improvement 39.33% 35.74%
Palmetto Power8:
Os O2 O3
median 50279 50599 35790
stddev 992144533 627130655 623721078
improvement 36.79% 37.13%
Romulus Power9:
Os O2 O3
median 670312391 454733720 448881398
stddev 157569 107276 108760
improvement 32.16% 33.03%
TCG was quite noisy, with every few runs producing an outlier. Even so,
O2 is faster than O3. On hardware the numbers were less noisy and O3 is
slightly faster than O2.
The wrapper size increases when moving from Os. Comparing zImage.epapr
to the existing Os build using bloat-o-meter:
Before=43401, After=56837 (13KB), chg +30.96%
Before=43401, After=64305 (20KB), chg +48.16%
I chose O2 for a balance between Qemu and hardware speed up.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This will avoid auto-vectorisation when building with higher
optimisation levels.
We don't know if the machine can support VSX and even if it's present
it's probably not going to be enabled at this point in boot.
These flag were both added prior to GCC 4.6 which is the minimum
compiler version supported by upstream, thanks to Segher for the
details.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As of commit 10c77dba40 ("powerpc/boot: Fix build failure in 32-bit
boot wrapper") the opal code is hidden behind CONFIG_PPC64_BOOT_WRAPPER,
but the boot wrapper avoids include/linux, so it does not get the normal
Kconfig flags.
We can drop the guard entirely as in commit f8e8e69cea ("powerpc/boot:
Only build OPAL code when necessary") the makefile only includes opal.c
in the build if CONFIG_PPC64_BOOT_WRAPPER is set.
Fixes: 10c77dba40 ("powerpc/boot: Fix build failure in 32-bit boot wrapper")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the wrapper is built without including anything in
$(src)/include/, which means there are no CONFIG_ symbols defined.
This means the platform specific serial drivers were never enabled.
We now copy the definitions into the boot directory, so any C file can
now include autoconf.h to depend on configuration options.
Fixes: 866bfc75f4 ("powerpc: conditionally compile platform-specific serial drivers")
Signed-off-by: Joel Stanley <joel@jms.id.au>
[mpe: Fix to use $(objtree) to find autoconf.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.
Also since commit f467c5640c ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:
...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently when we get an unknown RTAS event it prints the type as
"Unknown" and no other useful information. Add the raw type code to the
log message so that we have something to work off.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The powerpc kernel uses setjmp which causes a warning when building
with clang:
In file included from arch/powerpc/xmon/xmon.c:51:
./arch/powerpc/include/asm/setjmp.h:15:13: error: declaration of
built-in function 'setjmp' requires inclusion of the header <setjmp.h>
[-Werror,-Wbuiltin-requires-header]
extern long setjmp(long *);
^
./arch/powerpc/include/asm/setjmp.h:16:13: error: declaration of
built-in function 'longjmp' requires inclusion of the header <setjmp.h>
[-Werror,-Wbuiltin-requires-header]
extern void longjmp(long *, long);
^
This *is* the header and we're not using the built-in setjump but
rather the one in arch/powerpc/kernel/misc.S. As the compiler warning
does not make sense, it for the files where setjmp is used.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
[mpe: Move subdir-ccflags in xmon/Makefile to not clobber -Werror]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The "count < sizeof(struct os_area_db)" comparison is type promoted to
size_t so negative values of "count" are treated as very high values
and we accidentally return success instead of a negative error code.
This doesn't really change runtime much but it fixes a static checker
warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On a Power9 box we get a few screens full of these on boot. Drop
them to pr_debug.
[ 5.993645] nest_centaur6_imc performance monitor hardware support registered
[ 5.993728] nest_centaur7_imc performance monitor hardware support registered
[ 5.996510] core_imc performance monitor hardware support registered
[ 5.996569] nest_mba0_imc performance monitor hardware support registered
[ 5.996631] nest_mba1_imc performance monitor hardware support registered
[ 5.996685] nest_mba2_imc performance monitor hardware support registered
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Stewart Smith <stewart@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
instructions_to_print var is assigned value 16 and there is no
way to change it.
This patch replaces it by a constant.
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When two processes crash at the same time, we sometimes encounter
interleaving in the middle of a line:
init[1]: segfault (11) at 0 nip 0 lr 0 code 1
init[1]: code: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
init[74]: segfault (11) at 10a74 nip 1000c198 lr 100078c8 code 1 in sh[10000000+14000]
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
init[1]: code: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
init[74]: code: 90010024 bf61000c 91490a7c 3fa01002 3be00000 7d3e4b78 3bbd0c20 3b600000
init[74]: code: 3b9d0040 7c7fe02e 2f830000 419e0028 <89230000> 2f890000 41be001c 4b7f6e79
This patch fixes it by preparing complete lines in a buffer and
printing it at once.
Fixes: 88b0fe1757 ("powerpc: Add show_user_instructions()")
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Use seq_buf_printf() not seq_buf_puts() which doesn't NULL terminate]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As spotted by sparse:
arch/powerpc/kernel/process.c:1302:6: warning: symbol 'show_user_instructions' was not declared. Should it be static?
Fixes: 88b0fe1757 ("powerpc: Add show_user_instructions()")
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch fixes the following warnings, which are leftovers
from when __get_user() was replaced by probe_kernel_address().
arch/powerpc/kernel/process.c:1287:22: warning: incorrect type in argument 2 (different address spaces)
arch/powerpc/kernel/process.c:1287:22: expected void const *src
arch/powerpc/kernel/process.c:1287:22: got unsigned int [noderef] <asn:1>*<noident>
arch/powerpc/kernel/process.c:1319:21: warning: incorrect type in argument 2 (different address spaces)
arch/powerpc/kernel/process.c:1319:21: expected void const *src
arch/powerpc/kernel/process.c:1319:21: got unsigned int [noderef] <asn:1>*<noident>
Fixes: 7b051f665c ("powerpc: Use probe_kernel_address in show_instructions")
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Since the struct lsm_info table is not an initcall, we can just move it
into INIT_DATA like all the other tables.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a
result we will see warnings such as:
BUG: Bad page map in process JobWrk0013 pte:800001803875ea25 pmd:7624381067
addr:00007f0930720000 vm_flags:280000f9 anon_vma: (null) mapping:ffff97f2384056f0 index:0
file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage: (null)
CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G W 4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased)
Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
Call Trace:
dump_stack+0x5a/0x75
print_bad_pte+0x217/0x2c0
? enqueue_task_fair+0x76/0x9f0
_vm_normal_page+0xe5/0x100
zap_pte_range+0x148/0x740
unmap_page_range+0x39a/0x4b0
unmap_vmas+0x42/0x90
unmap_region+0x99/0xf0
? vma_gap_callbacks_rotate+0x1a/0x20
do_munmap+0x255/0x3a0
vm_munmap+0x54/0x80
SyS_munmap+0x1d/0x30
do_syscall_64+0x74/0x150
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
...
when mprotect(2) gets used on DAX mappings. Also there is a wide variety
of other failures that can result from the missing _PAGE_DEVMAP flag
when the area gets used by get_user_pages() later.
Fix the problem by including _PAGE_DEVMAP in a set of flags that get
preserved by mprotect(2).
Fixes: 69660fd797 ("x86, mm: introduce _PAGE_DEVMAP")
Fixes: ebd3119793 ("powerpc/mm: Add devmap support for ppc64")
Cc: <stable@vger.kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This adds a KVM_PPC_NO_HASH flag to the flags field of the
kvm_ppc_smmu_info struct, and arranges for it to be set when
running as a nested hypervisor, as an unambiguous indication
to userspace that HPT guests are not supported. Reporting the
KVM_CAP_PPC_MMU_HASH_V3 capability as false could be taken as
indicating only that the new HPT features in ISA V3.0 are not
supported, leaving it ambiguous whether pre-V3.0 HPT features
are supported.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
With this, userspace can enable a KVM-HV guest to run nested guests
under it.
The administrator can control whether any nested guests can be run;
setting the "nested" module parameter to false prevents any guests
becoming nested hypervisors (that is, any attempt to enable the nested
capability on a guest will fail). Guests which are already nested
hypervisors will continue to be so.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This merges in the "ppc-kvm" topic branch of the powerpc tree to get a
series of commits that touch both general arch/powerpc code and KVM
code. These commits will be merged both via the KVM tree and the
powerpc tree.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds a list of valid shadow PTEs for each nested guest to
the 'radix' file for the guest in debugfs. This can be useful for
debugging.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With this, the KVM-HV module can be loaded in a guest running under
KVM-HV, and if the hypervisor supports nested virtualization, this
guest can now act as a nested hypervisor and run nested guests.
This also adds some checks to inform userspace that HPT guests are not
supported by nested hypervisors (by returning false for the
KVM_CAP_PPC_MMU_HASH_V3 capability), and to prevent userspace from
configuring a guest to use HPT mode.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The hcall H_ENTER_NESTED takes two parameters: the address in L1 guest
memory of a hv_regs struct and the address of a pt_regs struct. The
hcall requests the L0 hypervisor to use the register values in these
structs to run a L2 guest and to return the exit state of the L2 guest
in these structs. These are in the endianness of the L1 guest, rather
than being always big-endian as is usually the case for PAPR
hypercalls.
This is convenient because it means that the L1 guest can pass the
address of the regs field in its kvm_vcpu_arch struct. This also
improves performance slightly by avoiding the need for two copies of
the pt_regs struct.
When reading/writing these structures, this patch handles the case
where the endianness of the L1 guest differs from that of the L0
hypervisor, by byteswapping the structures after reading and before
writing them back.
Since all the fields of the pt_regs are of the same type, i.e.,
unsigned long, we treat it as an array of unsigned longs. The fields
of struct hv_guest_state are not all the same, so its fields are
byteswapped individually.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
restore_hv_regs() is used to copy the hv_regs L1 wants to set to run the
nested (L2) guest into the vcpu structure. We need to sanitise these
values to ensure we don't let the L1 guest hypervisor do things we don't
want it to.
We don't let data address watchpoints or completed instruction address
breakpoints be set to match in hypervisor state.
We also don't let L1 enable features in the hypervisor facility status
and control register (HFSCR) for L2 which we have disabled for L1. That
is L2 will get the subset of features which the L0 hypervisor has
enabled for L1 and the features L1 wants to enable for L2. This could
mean we give L1 a hypervisor facility unavailable interrupt for a
facility it thinks it has enabled, however it shouldn't have enabled a
facility it itself doesn't have for the L2 guest.
We sanitise the registers when copying in the L2 hv_regs. We don't need
to sanitise when copying back the L1 hv_regs since these shouldn't be
able to contain invalid values as they're just what was copied out.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a one-reg register identifier which can be used to read and
set the virtual PTCR for the guest. This register identifies the
address and size of the virtual partition table for the guest, which
contains information about the nested guests under this guest.
Migrating this value is the only extra requirement for migrating a
guest which has nested guests (assuming of course that the destination
host supports nested virtualization in the kvm-hv module).
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When running as a nested hypervisor, this avoids reading hypervisor
privileged registers (specifically HFSCR, LPIDR and LPCR) at startup;
instead reasonable default values are used. This also avoids writing
LPIDR in the single-vcpu entry/exit path.
Also, this removes the check for CPU_FTR_HVMODE in kvmppc_mmu_hv_init()
since its only caller already checks this.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This is only done at level 0, since only level 0 knows which physical
CPU a vcpu is running on. This does for nested guests what L0 already
did for its own guests, which is to flush the TLB on a pCPU when it
goes to run a vCPU there, and there is another vCPU in the same VM
which previously ran on this pCPU and has now started to run on another
pCPU. This is to handle the situation where the other vCPU touched
a mapping, moved to another pCPU and did a tlbiel (local-only tlbie)
on that new pCPU and thus left behind a stale TLB entry on this pCPU.
This introduces a limit on the the vcpu_token values used in the
H_ENTER_NESTED hcall -- they must now be less than NR_CPUS.
[paulus@ozlabs.org - made prev_cpu array be short[] to reduce
memory consumption.]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds code to call the H_TLB_INVALIDATE hypercall when running as
a guest, in the cases where we need to invalidate TLBs (or other MMU
caches) as part of managing the mappings for a nested guest. Calling
H_TLB_INVALIDATE lets the nested hypervisor inform the parent
hypervisor about changes to partition-scoped page tables or the
partition table without needing to do hypervisor-privileged tlbie
instructions.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When running a nested (L2) guest the guest (L1) hypervisor will use
the H_TLB_INVALIDATE hcall when it needs to change the partition
scoped page tables or the partition table which it manages. It will
use this hcall in the situations where it would use a partition-scoped
tlbie instruction if it were running in hypervisor mode.
The H_TLB_INVALIDATE hcall can invalidate different scopes:
Invalidate TLB for a given target address:
- This invalidates a single L2 -> L1 pte
- We need to invalidate any L2 -> L0 shadow_pgtable ptes which map the L2
address space which is being invalidated. This is because a single
L2 -> L1 pte may have been mapped with more than one pte in the
L2 -> L0 page tables.
Invalidate the entire TLB for a given LPID or for all LPIDs:
- Invalidate the entire shadow_pgtable for a given nested guest, or
for all nested guests.
Invalidate the PWC (page walk cache) for a given LPID or for all LPIDs:
- We don't cache the PWC, so nothing to do.
Invalidate the entire TLB, PWC and partition table for a given/all LPIDs:
- Here we re-read the partition table entry and remove the nested state
for any nested guest for which the first doubleword of the partition
table entry is now zero.
The H_TLB_INVALIDATE hcall takes as parameters the tlbie instruction
word (of which only the RIC, PRS and R fields are used), the rS value
(giving the lpid, where required) and the rB value (giving the IS, AP
and EPN values).
[paulus@ozlabs.org - adapted to having the partition table in guest
memory, added the H_TLB_INVALIDATE implementation, removed tlbie
instruction emulation, reworded the commit message.]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When a host (L0) page which is mapped into a (L1) guest is in turn
mapped through to a nested (L2) guest we keep a reverse mapping (rmap)
so that these mappings can be retrieved later.
Whenever we create an entry in a shadow_pgtable for a nested guest we
create a corresponding rmap entry and add it to the list for the
L1 guest memslot at the index of the L1 guest page it maps. This means
at the L1 guest memslot we end up with lists of rmaps.
When we are notified of a host page being invalidated which has been
mapped through to a (L1) guest, we can then walk the rmap list for that
guest page, and find and invalidate all of the corresponding
shadow_pgtable entries.
In order to reduce memory consumption, we compress the information for
each rmap entry down to 52 bits -- 12 bits for the LPID and 40 bits
for the guest real page frame number -- which will fit in a single
unsigned long. To avoid a scenario where a guest can trigger
unbounded memory allocations, we scan the list when adding an entry to
see if there is already an entry with the contents we need. This can
occur, because we don't ever remove entries from the middle of a list.
A struct nested guest rmap is a list pointer and an rmap entry;
----------------
| next pointer |
----------------
| rmap entry |
----------------
Thus the rmap pointer for each guest frame number in the memslot can be
either NULL, a single entry, or a pointer to a list of nested rmap entries.
gfn memslot rmap array
-------------------------
0 | NULL | (no rmap entry)
-------------------------
1 | single rmap entry | (rmap entry with low bit set)
-------------------------
2 | list head pointer | (list of rmap entries)
-------------------------
The final entry always has the lowest bit set and is stored in the next
pointer of the last list entry, or as a single rmap entry.
With a list of rmap entries looking like;
----------------- ----------------- -------------------------
| list head ptr | ----> | next pointer | ----> | single rmap entry |
----------------- ----------------- -------------------------
| rmap entry | | rmap entry |
----------------- -------------------------
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Consider a normal (L1) guest running under the main hypervisor (L0),
and then a nested guest (L2) running under the L1 guest which is acting
as a nested hypervisor. L0 has page tables to map the address space for
L1 providing the translation from L1 real address -> L0 real address;
L1
|
| (L1 -> L0)
|
----> L0
There are also page tables in L1 used to map the address space for L2
providing the translation from L2 real address -> L1 read address. Since
the hardware can only walk a single level of page table, we need to
maintain in L0 a "shadow_pgtable" for L2 which provides the translation
from L2 real address -> L0 real address. Which looks like;
L2 L2
| |
| (L2 -> L1) |
| |
----> L1 | (L2 -> L0)
| |
| (L1 -> L0) |
| |
----> L0 --------> L0
When a page fault occurs while running a nested (L2) guest we need to
insert a pte into this "shadow_pgtable" for the L2 -> L0 mapping. To
do this we need to:
1. Walk the pgtable in L1 memory to find the L2 -> L1 mapping, and
provide a page fault to L1 if this mapping doesn't exist.
2. Use our L1 -> L0 pgtable to convert this L1 address to an L0 address,
or try to insert a pte for that mapping if it doesn't exist.
3. Now we have a L2 -> L0 mapping, insert this into our shadow_pgtable
Once this mapping exists we can take rc faults when hardware is unable
to automatically set the reference and change bits in the pte. On these
we need to:
1. Check the rc bits on the L2 -> L1 pte match, and otherwise reflect
the fault down to L1.
2. Set the rc bits in the L1 -> L0 pte which corresponds to the same
host page.
3. Set the rc bits in the L2 -> L0 pte.
As we reuse a large number of functions in book3s_64_mmu_radix.c for
this we also needed to refactor a number of these functions to take
an lpid parameter so that the correct lpid is used for tlb invalidations.
The functionality however has remained the same.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we are running as a nested hypervisor, we use a hypercall to
enter the guest rather than code in book3s_hv_rmhandlers.S. This means
that the hypercall handlers listed in hcall_real_table never get called.
There are some hypercalls that are handled there and not in
kvmppc_pseries_do_hcall(), which therefore won't get processed for
a nested guest.
To fix this, we add cases to kvmppc_pseries_do_hcall() to handle those
hypercalls, with the following exceptions:
- The HPT hypercalls (H_ENTER, H_REMOVE, etc.) are not handled because
we only support radix mode for nested guests.
- H_CEDE has to be handled specially because the cede logic in
kvmhv_run_single_vcpu assumes that it has been processed by the time
that kvmhv_p9_guest_entry() returns. Therefore we put a special
case for H_CEDE in kvmhv_p9_guest_entry().
For the XICS hypercalls, if real-mode processing is enabled, then the
virtual-mode handlers assume that they are being called only to finish
up the operation. Therefore we turn off the real-mode flag in the XICS
code when running as a nested hypervisor.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds code to call the H_IPI and H_EOI hypercalls when we are
running as a nested hypervisor (i.e. without the CPU_FTR_HVMODE cpu
feature) and we would otherwise access the XICS interrupt controller
directly or via an OPAL call.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a new hypercall, H_ENTER_NESTED, which is used by a nested
hypervisor to enter one of its nested guests. The hypercall supplies
register values in two structs. Those values are copied by the level 0
(L0) hypervisor (the one which is running in hypervisor mode) into the
vcpu struct of the L1 guest, and then the guest is run until an
interrupt or error occurs which needs to be reported to L1 via the
hypercall return value.
Currently this assumes that the L0 and L1 hypervisors are the same
endianness, and the structs passed as arguments are in native
endianness. If they are of different endianness, the version number
check will fail and the hcall will be rejected.
Nested hypervisors do not support indep_threads_mode=N, so this adds
code to print a warning message if the administrator has set
indep_threads_mode=N, and treat it as Y.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This starts the process of adding the code to support nested HV-style
virtualization. It defines a new H_SET_PARTITION_TABLE hypercall which
a nested hypervisor can use to set the base address and size of a
partition table in its memory (analogous to the PTCR register).
On the host (level 0 hypervisor) side, the H_SET_PARTITION_TABLE
hypercall from the guest is handled by code that saves the virtual
PTCR value for the guest.
This also adds code for creating and destroying nested guests and for
reading the partition table entry for a nested guest from L1 memory.
Each nested guest has its own shadow LPID value, different in general
from the LPID value used by the nested hypervisor to refer to it. The
shadow LPID value is allocated at nested guest creation time.
Nested hypervisor functionality is only available for a radix guest,
which therefore means a radix host on a POWER9 (or later) processor.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
kvmppc_unmap_pte() does a sequence of operations that are open-coded in
kvm_unmap_radix(). This extends kvmppc_unmap_pte() a little so that it
can be used by kvm_unmap_radix(), and makes kvm_unmap_radix() call it.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The radix page fault handler accounts for all cases, including just
needing to insert a pte. This breaks it up into separate functions for
the two main cases; setting rc and inserting a pte.
This allows us to make the setting of rc and inserting of a pte
generic for any pgtable, not specific to the one for this guest.
[paulus@ozlabs.org - reduced diffs from previous code]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
kvmppc_mmu_radix_xlate() is used to translate an effective address
through the process tables. The process table and partition tables have
identical layout. Exploit this fact to make the kvmppc_mmu_radix_xlate()
function able to translate either an effective address through the
process tables or a guest real address through the partition tables.
[paulus@ozlabs.org - reduced diffs from previous code]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When destroying a VM we return the LPID to the pool, however we never
zero the partition table entry. This is instead done when we reallocate
the LPID.
Zero the partition table entry on VM teardown before returning the LPID
to the pool. This means if we were running as a nested hypervisor the
real hypervisor could use this to determine when it can free resources.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the 'regs' field was added to struct kvm_vcpu_arch, the code
was changed to use several of the fields inside regs (e.g., gpr, lr,
etc.) but not the ccr field, because the ccr field in struct pt_regs
is 64 bits on 64-bit platforms, but the cr field in kvm_vcpu_arch is
only 32 bits. This changes the code to use the regs.ccr field
instead of cr, and changes the assembly code on 64-bit platforms to
use 64-bit loads and stores instead of 32-bit ones.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a file called 'radix' in the debugfs directory for the
guest, which when read gives all of the valid leaf PTEs in the
partition-scoped radix tree for a radix guest, in human-readable
format. It is analogous to the existing 'htab' file which dumps
the HPT entries for a HPT guest.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the code for handling hypervisor instruction page faults
passes 0 for the flags indicating the type of fault, which is OK in
the usual case that the page is not mapped in the partition-scoped
page tables. However, there are other causes for hypervisor
instruction page faults, such as not being to update a reference
(R) or change (C) bit. The cause is indicated in bits in HSRR1,
including a bit which indicates that the fault is due to not being
able to write to a page (for example to update an R or C bit).
Not handling these other kinds of faults correctly can lead to a
loop of continual faults without forward progress in the guest.
In order to handle these faults better, this patch constructs a
"DSISR-like" value from the bits which DSISR and SRR1 (for a HISI)
have in common, and passes it to kvmppc_book3s_hv_page_fault() so
that it knows what caused the fault.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This creates an alternative guest entry/exit path which is used for
radix guests on POWER9 systems when we have indep_threads_mode=Y. In
these circumstances there is exactly one vcpu per vcore and there is
no coordination required between vcpus or vcores; the vcpu can enter
the guest without needing to synchronize with anything else.
The new fast path is implemented almost entirely in C in book3s_hv.c
and runs with the MMU on until the guest is entered. On guest exit
we use the existing path until the point where we are committed to
exiting the guest (as distinct from handling an interrupt in the
low-level code and returning to the guest) and we have pulled the
guest context from the XIVE. At that point we check a flag in the
stack frame to see whether we came in via the old path and the new
path; if we came in via the new path then we go back to C code to do
the rest of the process of saving the guest context and restoring the
host context.
The C code is split into separate functions for handling the
OS-accessible state and the hypervisor state, with the idea that the
latter can be replaced by a hypercall when we implement nested
virtualization.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[mpe: Fix CONFIG_ALTIVEC=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently kvmppc_handle_exit_hv() is called with the vcore lock held
because it is called within a for_each_runnable_thread loop.
However, we already unlock the vcore within kvmppc_handle_exit_hv()
under certain circumstances, and this is safe because (a) any vcpus
that become runnable and are added to the runnable set by
kvmppc_run_vcpu() have their vcpu->arch.trap == 0 and can't actually
run in the guest (because the vcore state is VCORE_EXITING), and
(b) for_each_runnable_thread is safe against addition or removal
of vcpus from the runnable set.
Therefore, in order to simplify things for following patches, let's
drop the vcore lock in the for_each_runnable_thread loop, so
kvmppc_handle_exit_hv() gets called without the vcore lock held.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a parameter to __kvmppc_save_tm and __kvmppc_restore_tm
which allows the caller to indicate whether it wants the nonvolatile
register state to be preserved across the call, as required by the C
calling conventions. This parameter being non-zero also causes the
MSR bits that enable TM, FP, VMX and VSX to be preserved. The
condition register and DSCR are now always preserved.
With this, kvmppc_save_tm_hv and kvmppc_restore_tm_hv can be called
from C code provided the 3rd parameter is non-zero. So that these
functions can be called from modules, they now include code to set
the TOC pointer (r2) on entry, as they can call other built-in C
functions which will assume the TOC to have been set.
Also, the fake suspend code in kvmppc_save_tm_hv is modified here to
assume that treclaim in fake-suspend state does not modify any registers,
which is the case on POWER9. This enables the code to be simplified
quite a bit.
_kvmppc_save_tm_pr and _kvmppc_restore_tm_pr become much simpler with
this change, since they now only need to save and restore TAR and pass
1 for the 3rd argument to __kvmppc_{save,restore}_tm.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This streamlines the first part of the code that handles a hypervisor
interrupt that occurred in the guest. With this, all of the real-mode
handling that occurs is done before the "guest_exit_cont" label; once
we get to that label we are committed to exiting to host virtual mode.
Thus the machine check and HMI real-mode handling is moved before that
label.
Also, the code to handle external interrupts is moved out of line, as
is the code that calls kvmppc_realmode_hmi_handler().
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This pulls out the assembler code that is responsible for saving and
restoring the PMU state for the host and guest into separate functions
so they can be used from an alternate entry path. The calling
convention is made compatible with C.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This is based on a patch by Suraj Jitindar Singh.
This moves the code in book3s_hv_rmhandlers.S that generates an
external, decrementer or privileged doorbell interrupt just before
entering the guest to C code in book3s_hv_builtin.c. This is to
make future maintenance and modification easier. The algorithm
expressed in the C code is almost identical to the previous
algorithm.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This removes code that clears the external interrupt pending bit in
the pending_exceptions bitmap. This is left over from an earlier
iteration of the code where this bit was set when an escalation
interrupt arrived in order to wake the vcpu from cede. Currently
we set the vcpu->arch.irq_pending flag instead for this purpose.
Therefore there is no need to do anything with the pending_exceptions
bitmap.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we use two bits in the vcpu pending_exceptions bitmap to
indicate that an external interrupt is pending for the guest, one
for "one-shot" interrupts that are cleared when delivered, and one
for interrupts that persist until cleared by an explicit action of
the OS (e.g. an acknowledge to an interrupt controller). The
BOOK3S_IRQPRIO_EXTERNAL bit is used for one-shot interrupt requests
and BOOK3S_IRQPRIO_EXTERNAL_LEVEL is used for persisting interrupts.
In practice BOOK3S_IRQPRIO_EXTERNAL never gets used, because our
Book3S platforms generally, and pseries in particular, expect
external interrupt requests to persist until they are acknowledged
at the interrupt controller. That combined with the confusion
introduced by having two bits for what is essentially the same thing
makes it attractive to simplify things by only using one bit. This
patch does that.
With this patch there is only BOOK3S_IRQPRIO_EXTERNAL, and by default
it has the semantics of a persisting interrupt. In order to avoid
breaking the ABI, we introduce a new "external_oneshot" flag which
preserves the behaviour of the KVM_INTERRUPT ioctl with the
KVM_INTERRUPT_SET argument.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When doing nested virtualization, it is only necessary to do the
transactional memory hypervisor assist at level 0, that is, when
we are in hypervisor mode. Nested hypervisors can just use the TM
facilities as architected. Therefore we should clear the
CPU_FTR_P9_TM_HV_ASSIST bit when we are not in hypervisor mode,
along with the CPU_FTR_HVMODE bit.
Doing this will not change anything at this stage because the only
code that tests CPU_FTR_P9_TM_HV_ASSIST is in HV KVM, which currently
can only be used when when CPU_FTR_HVMODE is set.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The kvmppc_gpa_to_ua() helper itself takes care of the permission
bits in the TCE and yet every single caller removes them.
This changes semantics of kvmppc_gpa_to_ua() so it takes TCEs
(which are GPAs + TCE permission bits) to make the callers simpler.
This should cause no behavioural change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
At the moment if the PUT_TCE{_INDIRECT} handlers fail to update
the hardware tables, we print a warning once, clear the entry and
continue. This is so as at the time the assumption was that if
a VFIO device is hotplugged into the guest, and the userspace replays
virtual DMA mappings (i.e. TCEs) to the hardware tables and if this fails,
then there is nothing useful we can do about it.
However the assumption is not valid as these handlers are not called for
TCE replay (VFIO ioctl interface is used for that) and these handlers
are for new TCEs.
This returns an error to the guest if there is a request which cannot be
processed. By now the only possible failure must be H_TOO_HARD.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The userspace can request an arbitrary supported page size for a DMA
window and this works fine as long as the mapped memory is backed with
the pages of the same or bigger size; if this is not the case,
mm_iommu_ua_to_hpa{_rm}() fail and tables do not populated with
dangerously incorrect TCEs.
However since it is quite easy to misconfigure the KVM and we do not do
reverts to all changes made to TCE tables if an error happens in a middle,
we better do the acceptable page size validation before we even touch
the tables.
This enhances kvmppc_tce_validate() to check the hardware IOMMU page sizes
against the preregistered memory page sizes.
Since the new check uses real/virtual mode helpers, this renames
kvmppc_tce_validate() to kvmppc_rm_tce_validate() to handle the real mode
case and mirrors it for the virtual mode under the old name. The real
mode handler is not used for the virtual mode as:
1. it uses _lockless() list traversing primitives instead of RCU;
2. realmode's mm_iommu_ua_to_hpa_rm() uses vmalloc_to_phys() which
virtual mode does not have to use and since on POWER9+radix only virtual
mode handlers actually work, we do not want to slow down that path even
a bit.
This removes EXPORT_SYMBOL_GPL(kvmppc_tce_validate) as the validators
are static now.
From now on the attempts on mapping IOMMU pages bigger than allowed
will result in KVM exit.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[mpe: Fix KVM_HV=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that the 68k Mac port has adopted the via-pmu driver, the same RTC
code can be shared between m68k and powerpc. Replace duplicated code in
arch/powerpc and arch/m68k with common RTC accessors for Cuda and PMU.
Drop the problematic WARN_ON which was introduced in commit 22db552b50
("powerpc/powermac: Fix rtc read/write functions").
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Four regression fixes.
A fix for a change to lib/xz which broke our zImage loader when building with XZ
compression. OK'ed by Herbert who merged the original patch.
The recent fix we did to avoid patching __init text broke some 32-bit machines,
fix that.
Our show_user_instructions() could be tricked into printing kernel memory, add a
check to avoid that.
And a fix for a change to our NUMA initialisation logic, which causes crashes in
some kdump configurations.
Thanks to:
Christophe Leroy, Hari Bathini, Jann Horn, Joel Stanley, Meelis Roos, Murilo
Opsfelder Araujo, Srikar Dronamraju.
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Merge tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Michael writes:
"powerpc fixes for 4.19 #4
Four regression fixes.
A fix for a change to lib/xz which broke our zImage loader when
building with XZ compression. OK'ed by Herbert who merged the
original patch.
The recent fix we did to avoid patching __init text broke some 32-bit
machines, fix that.
Our show_user_instructions() could be tricked into printing kernel
memory, add a check to avoid that.
And a fix for a change to our NUMA initialisation logic, which causes
crashes in some kdump configurations.
Thanks to:
Christophe Leroy, Hari Bathini, Jann Horn, Joel Stanley, Meelis
Roos, Murilo Opsfelder Araujo, Srikar Dronamraju."
* tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/numa: Skip onlining a offline node in kdump path
powerpc: Don't print kernel instructions in show_user_instructions()
powerpc/lib: fix book3s/32 boot failure due to code patching
lib/xz: Put CRC32_POLY_LE in xz_private.h
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Paolo writes:
"KVM changes for 4.19-rc7
x86 and PPC bugfixes, mostly introduced in 4.19-rc1."
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: nVMX: fix entry with pending interrupt if APICv is enabled
KVM: VMX: hide flexpriority from guest when disabled at the module level
KVM: VMX: check for existence of secondary exec controls before accessing
KVM: PPC: Book3S HV: Avoid crash from THP collapse during radix page fault
KVM: x86: fix L1TF's MMIO GFN calculation
tools/kvm_stat: cut down decimal places in update interval dialog
KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS
KVM: x86: Do not use kvm_x86_ops->mpx_supported() directly
KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled
KVM: x86: never trap MSR_KERNEL_GS_BASE
Recently we implemented show_user_instructions() which dumps the code
around the NIP when a user space process dies with an unhandled
signal. This was modelled on the x86 code, and we even went so far as
to implement the exact same bug, namely that if the user process
crashed with its NIP pointing into the kernel we will dump kernel text
to dmesg. eg:
bad-bctr[2996]: segfault (11) at c000000000010000 nip c000000000010000 lr 12d0b0894 code 1
bad-bctr[2996]: code: fbe10068 7cbe2b78 7c7f1b78 fb610048 38a10028 38810020 fb810050 7f8802a6
bad-bctr[2996]: code: 3860001c f8010080 48242371 60000000 <7c7b1b79> 4082002c e8010080 eb610048
This was discovered on x86 by Jann Horn and fixed in commit
342db04ae7 ("x86/dumpstack: Don't dump kernel memory based on usermode RIP").
Fix it by checking the adjusted NIP value (pc) and number of
instructions against USER_DS, and bail if we fail the check, eg:
bad-bctr[2969]: segfault (11) at c000000000010000 nip c000000000010000 lr 107930894 code 1
bad-bctr[2969]: Bad NIP, not dumping instructions.
Fixes: 88b0fe1757 ("powerpc: Add show_user_instructions()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a mode where the vcore scheduling logic in HV KVM limits itself
to scheduling only virtual cores from the same VM on any given physical
core. This is enabled via a new module parameter on the kvm-hv module
called "one_vm_per_core". For this to work on POWER9, it is necessary to
set indep_threads_mode=N. (On POWER8, hardware limitations mean that KVM
is never in independent threads mode, regardless of the indep_threads_mode
setting.)
Thus the settings needed for this to work are:
1. The host is in SMT1 mode.
2. On POWER8, the host is not in 2-way or 4-way static split-core mode.
3. On POWER9, the indep_threads_mode parameter is N.
4. The one_vm_per_core parameter is Y.
With these settings, KVM can run up to 4 vcpus on a core at the same
time on POWER9, or up to 8 vcpus on POWER8 (depending on the guest
threading mode), and will ensure that all of the vcpus belong to the
same VM.
This is intended for use in security-conscious settings where users are
concerned about possible side-channel attacks between threads which could
perhaps enable one VM to attack another VM on the same core, or the host.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When an OS (currently only classic Mac OS) is running in KVM-PR and makes a
linked jump from code with split hack addressing enabled into code that does
not, LR is not correctly updated and reflects the previously munged PC.
To fix this, this patch undoes the address munge when exiting split
hack mode so that code relying on LR being a proper address will now
execute. This does not affect OS X or other operating systems running
on KVM-PR.
Signed-off-by: Cameron Kaiser <spectre@floodgap.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Local radix TLB flush operations that operate on congruence classes
have explicit ERAT flushes for POWER9. The process scoped LPID flush
did not have a flush, so add it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PPC_INVALIDATE_ERAT is slbia IH=7 which is a new variant introduced
with POWER9, and the result is undefined on earlier CPUs.
Commits 7b9f71f974 ("powerpc/64s: POWER9 machine check handler") and
d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on
POWER9") caused POWER7/8 code to use this instruction. Remove it. An
ERAT flush can be made by invalidatig the SLB, but before POWER9 that
requires a flush and rebolt.
Fixes: 7b9f71f974 ("powerpc/64s: POWER9 machine check handler")
Fixes: d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If CONFIG_PPC_WATCHDOG is enabled we always cap the decrementer to
0x7fffffff:
if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
set_dec(0x7fffffff);
else
set_dec(decrementer_max);
If there are no future events, we don't reprogram the decrementer
after this and we end up with 0x7fffffff even on a large decrementer
capable system.
As suggested by Nick, add a set_state_oneshot_stopped callback
so we program the decrementer with decrementer_max if there are
no future events.
Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We currently cap the decrementer clockevent at 4 seconds, even on systems
with large decrementer support. Fix this by converting the code to use
clockevents_register_device() which calculates the upper bound based on
the max_delta passed in.
Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This threshold is no longer used now that all invalidates issue a single
ATSD to each active NPU.
Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Prior to this change only two types of ATSDs were issued to the NPU:
invalidates targeting a single page and invalidates targeting the whole
address space. The crossover point happened at the configurable
atsd_threshold which defaulted to 2M. Invalidates that size or smaller
would issue per-page invalidates for the whole range.
The NPU supports more invalidation sizes however: 64K, 2M, 1G, and all.
These invalidates target addresses aligned to their size. 2M is a common
invalidation size for GPU-enabled applications because that is a GPU
page size, so reducing the number of invalidates by 32x in that case is a
clear improvement.
ATSD latency is high in general so now we always issue a single invalidate
rather than multiple. This will over-invalidate in some cases, but for any
invalidation size over 2M it matches or improves the prior behavior.
There's also an improvement for single-page invalidates since the prior
version issued two invalidates for that case instead of one.
With this change all issued ATSDs now perform a flush, so the flush
parameter has been removed from all the helpers.
To show the benefit here are some performance numbers from a
microbenchmark which creates a 1G allocation then uses mprotect with
PROT_NONE to trigger invalidates in strides across the allocation.
One NPU (1 GPU):
mprotect rate (GB/s)
Stride Before After Speedup
64K 5.3 5.6 5%
1M 39.3 57.4 46%
2M 49.7 82.6 66%
4M 286.6 285.7 0%
Two NPUs (6 GPUs):
mprotect rate (GB/s)
Stride Before After Speedup
64K 6.5 7.4 13%
1M 33.4 67.9 103%
2M 38.7 93.1 141%
4M 356.7 354.6 -1%
Anything over 2M is roughly the same as before since both cases issue a
single ATSD.
Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-By: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are two types of ATSDs issued to the NPU: invalidates targeting a
specific virtual address and invalidates targeting the whole address
space. In both cases prior to this change, the sequence was:
for each NPU
- Write the target address to the XTS_ATSD_AVA register
- EIEIO
- Write the launch value to issue the ATSD
First, a target address is not required when invalidating the whole
address space, so that write and the EIEIO have been removed. The AP
(size) field in the launch is not needed either.
Second, for per-address invalidates the above sequence is inefficient in
the common case of multiple NPUs because an EIEIO is issued per NPU. This
unnecessarily forces the launches of later ATSDs to be ordered with the
launches of earlier ones. The new sequence only issues a single EIEIO:
for each NPU
- Write the target address to the XTS_ATSD_AVA register
EIEIO
for each NPU
- Write the launch value to issue the ATSD
Performance results were gathered using a microbenchmark which creates a
1G allocation then uses mprotect with PROT_NONE to trigger invalidates in
strides across the allocation.
With only a single NPU active (one GPU) the difference is in the noise for
both types of invalidates (+/-1%).
With two NPUs active (on a 6-GPU system) the effect is more noticeable:
mprotect rate (GB/s)
Stride Before After Speedup
64K 5.9 6.5 10%
1M 31.2 33.4 7%
2M 36.3 38.7 7%
4M 322.6 356.7 11%
Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Clean up the leftover of commit f2910f0e68 ("powerpc: remove old
GCC version checks").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When enumerating page size definitions to check hardware support,
we construct a constant which is (1U << (def->shift - 10)).
However, the array of page size definitions is only initalised for
various MMU_PAGE_* constants, so it contains a number of 0-initialised
elements with def->shift == 0. This means we end up shifting by a
very large number, which gives the following UBSan splat:
================================================================================
UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21
shift exponent 4294967286 is too large for 32-bit type 'unsigned int'
CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6
Call Trace:
[c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable)
[c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64
[c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4
[c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0
[c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130
[c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80
================================================================================
Fix this by first checking if the element exists (shift != 0) before
constructing the constant.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 71d29f43b6 ("KVM: PPC: Book3S HV: Don't use compound_order to
determine host mapping size", 2018-09-11) added a call to
__find_linux_pte() and a dereference of the returned PTE pointer to the
radix page fault path in the common case where the page is normal
system memory. Previously, __find_linux_pte() was only called for
mappings to physical addresses which don't have a page struct (e.g.
memory-mapped I/O) or where the page struct is marked as reserved
memory.
This exposes us to the possibility that the returned PTE pointer
could be NULL, for example in the case of a concurrent THP collapse
operation. Dereferencing the returned NULL pointer causes a host
crash.
To fix this, we check for NULL, and if it is NULL, we retry the
operation by returning to the guest, with the expectation that it
will generate the same page fault again (unless of course it has
been fixed up by another CPU in the meantime).
Fixes: 71d29f43b6 ("KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping size")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Rework the defintion of struct siginfo so that the array padding
struct siginfo to SI_MAX_SIZE can be placed in a union along side of
the rest of the struct siginfo members. The result is that we no
longer need the __ARCH_SI_PREAMBLE_SIZE or SI_PAD_SIZE definitions.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Add call to early_memtest() so that kernel compiled with
CONFIG_MEMTEST really perform memtest at startup when requested
via 'memtest' boot parameter.
Tested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When a process allocates a hugepage, the following leak is
reported by kmemleak. This is a false positive which is
due to the pointer to the table being stored in the PGD
as physical memory address and not virtual memory pointer.
unreferenced object 0xc30f8200 (size 512):
comm "mmap", pid 374, jiffies 4872494 (age 627.630s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<e32b68da>] huge_pte_alloc+0xdc/0x1f8
[<9e0df1e1>] hugetlb_fault+0x560/0x8f8
[<7938ec6c>] follow_hugetlb_page+0x14c/0x44c
[<afbdb405>] __get_user_pages+0x1c4/0x3dc
[<b8fd7cd9>] __mm_populate+0xac/0x140
[<3215421e>] vm_mmap_pgoff+0xb4/0xb8
[<c148db69>] ksys_mmap_pgoff+0xcc/0x1fc
[<4fcd760f>] ret_from_syscall+0x0/0x38
See commit a984506c54 ("powerpc/mm: Don't report PUDs as
memory leaks when using kmemleak") for detailed explanation.
To fix that, this patch tells kmemleak to ignore the allocated
hugepage table.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The comments in this file don't conform to the coding style so take
them to "Comment Formatting Re-Education Camp".
Suggested-by: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Neuling <mikey@neuling.org>
[mpe: Reflow some comments and add full stops, fix spelling of Sergeant.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
for 64bit configs which use for CONFIG_LOG_BUF_SHIFT the same
or higher value than the default (currently 17).
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The code in machine_check_exception excludes 64s hvmode when
incrementing the MCE counter only to call opal_machine_check to
increment it specifically for this case.
Remove the exclusion and special case.
Fixes: a43c159042 ("powerpc/pseries: Flush SLB contents on SLB MCE
errors.")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On a kernel TM Bad thing program exception, the Machine State Register
(MSR) is not being properly displayed. The exception code dumps a 32-bits
value but MSR is a 64 bits register for all platforms that have HTM
enabled.
This patch dumps the MSR value as a 64-bits value instead of 32 bits. In
order to do so, the 'reason' variable could not be used, since it trimmed
MSR to 32-bits (int).
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently msr_tm_active() is a wrapper around MSR_TM_ACTIVE() if
CONFIG_PPC_TRANSACTIONAL_MEM is set, or it is just a function that
returns false if CONFIG_PPC_TRANSACTIONAL_MEM is not set.
This function is not necessary, since MSR_TM_ACTIVE() just do the same and
could be used, removing the dualism and simplifying the code.
This patchset remove every instance of msr_tm_active() and replaced it
by MSR_TM_ACTIVE().
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is a mismatch between function pnv_platform_error_reboot() definition
and declaration regarding function modifiers. In the declaration part, it
contains the function attribute __noreturn, while function definition
itself lacks it.
This was reported by sparse tool as an error:
arch/powerpc/platforms/powernv/opal.c:538:6: error: symbol 'pnv_platform_error_reboot' redeclared with different type (originally declared at arch/powerpc/platforms/powernv/powernv.h:11) - different modifiers
I checked and the function is already being considered as being 'noreturn'
by the compiler, thus, I understand this patch does not change any code
being generated.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This is a patch that adds support for PTRACE_SYSEMU ptrace request in
PowerPC architecture.
When ptrace(PTRACE_SYSEMU, ...) request is called, it will be handled by
the arch independent function ptrace_resume(), which will tag the task with
the TIF_SYSCALL_EMU flag. This flag needs to be handled from a platform
dependent point of view, which is what this patch does.
This patch adds this task's flag as part of the _TIF_SYSCALL_DOTRACE, which
is the MACRO that is used to trace syscalls at entrance/exit.
Since TIF_SYSCALL_EMU is now part of _TIF_SYSCALL_DOTRACE, if the task has
_TIF_SYSCALL_DOTRACE set, it will hit do_syscall_trace_enter() at syscall
entrance and do_syscall_trace_leave() at syscall leave.
do_syscall_trace_enter() needs to handle the TIF_SYSCALL_EMU flag properly,
which will interrupt the syscall executing if TIF_SYSCALL_EMU is set. The
output values should not be changed, i.e. the return value (r3) should
contain the original syscall argument on exit.
With this flag set, the syscall is not executed fundamentally, because
do_syscall_trace_enter() is returning -1 which is bigger than NR_syscall,
thus, skipping the syscall execution and exiting userspace.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Moving TIF_32BIT to use bit 20 instead of 4 in the task flag field.
This change is making room for an upcoming new task macro
(_TIF_SYSCALL_EMU) which is preferred to set a bit in the lower 16-bits
part of the word.
This upcoming flag macro will take part in a composed macro
(_TIF_SYSCALL_DOTRACE) which will contain other flags as well, and it is
preferred that the whole _TIF_SYSCALL_DOTRACE macro only sets the lower 16
bits of a word, so, it could be handled using immediate operations (as load
immediate, add immediate, ...) where the immediate operand (SI) is limited
to 16-bits.
Another possible solution would be using the LOAD_REG_IMMEDIATE() macro
to load a full 64-bits word immediate, but it takes 5 operations instead of
one.
Having TIF_32BITS being redefined to use an upper bit is not a problem
since there is only one place in the assembly code where TIF_32BIT is being
used, and it could be replaced with an operation with right shift (addis),
since it is used alone, i.e. not being part of a composed macro, which has
different bits set, and would require LOAD_REG_IMMEDIATE().
Tested on a 64 bits Big Endian machine running a 32 bits task.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On PPC64, as register r13 points to the paca_struct at all time,
this patch adds a copy of the canary there, which is copied at
task_switch.
That new canary is then used by using the following GCC options:
-mstack-protector-guard=tls
-mstack-protector-guard-reg=r13
-mstack-protector-guard-offset=offsetof(struct paca_struct, canary))
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This functionality was tentatively added in the past
(commit 6533b7c16e ("powerpc: Initial stack protector
(-fstack-protector) support")) but had to be reverted
(commit f2574030b0 ("powerpc: Revert the initial stack
protector support") because of GCC implementing it differently
whether it had been built with libc support or not.
Now, GCC offers the possibility to manually set the
stack-protector mode (global or tls) regardless of libc support.
This time, the patch selects HAVE_STACKPROTECTOR only if
-mstack-protector-guard=tls is supported by GCC.
On PPC32, as register r2 points to current task_struct at
all time, the stack_canary located inside task_struct can be
used directly by using the following GCC options:
-mstack-protector-guard=tls
-mstack-protector-guard-reg=r2
-mstack-protector-guard-offset=offsetof(struct task_struct, stack_canary))
The protector is disabled for prom_init and bootx_init as
it is too early to handle it properly.
$ echo CORRUPT_STACK > /sys/kernel/debug/provoke-crash/DIRECT
[ 134.943666] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: lkdtm_CORRUPT_STACK+0x64/0x64
[ 134.943666]
[ 134.955414] CPU: 0 PID: 283 Comm: sh Not tainted 4.18.0-s3k-dev-12143-ga3272be41209 #835
[ 134.963380] Call Trace:
[ 134.965860] [c6615d60] [c001f76c] panic+0x118/0x260 (unreliable)
[ 134.971775] [c6615dc0] [c001f654] panic+0x0/0x260
[ 134.976435] [c6615dd0] [c032c368] lkdtm_CORRUPT_STACK_STRONG+0x0/0x64
[ 134.982769] [c6615e00] [ffffffff] 0xffffffff
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the dereference of xc below the NULL test.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we look up dtl_idx in
the lppaca to determine the number of entries in the buffer. Since
lppaca is in big endian, we need to do an endian conversion before using
this in our calculation to determine the number of entries in the
buffer. Without this, we do not iterate over the existing entries in the
DTL buffer properly.
Fixes: 7c105b63bd ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we register the DTL
buffer for a cpu when the associated file under powerpc/dtl in debugfs
is opened. When doing so, we need to set the size of the buffer being
registered in the second u32 word of the buffer. This needs to be in big
endian, but we are not doing the conversion resulting in the below error
showing up in dmesg:
dtl_start: DTL registration for cpu 0 (hw 0) failed with -4
Fix this in the obvious manner.
Fixes: 7c105b63bd ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PPC32 uses nonrecoverable_exception() while PPC64 uses
unrecoverable_exception().
Both functions are doing almost the same thing.
This patch removes nonrecoverable_exception()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Instead of calling both of_irq_parse_one() and
irq_create_of_mapping(), call of_irq_get() instead which does
essentially the same thing. of_irq_get() also calls irq_find_host()
for deferred probe support, but this should be fine as
irq_create_of_mapping() also calls that internally. This gets us
closer to making the former 2 functions static.
In the process of simplifying request_event_sources_irqs(), combine
the the pr_err() and WARN_ON() calls to just a WARN().
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Instead of calling both of_irq_parse_one() and
irq_create_of_mapping(), call of_irq_parse_and_map() instead which
does the same thing. This gets us closer to making the former 2
functions static.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We need to make sure pmd_trans_huge returns false for a pmd migration entry.
We mark the migration entry by clearing the _PAGE_PRESENT bit. We keep the
_PAGE_PTE bit set to indicate a leaf page table entry. Hence we need to make
sure we check for pmd_present() so that pmd_trans_huge won't return true on
pmd migration entry.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Make sure we are operating on THP and hugetlb entries in the respective hash
fault handling routines.
No functional change in this patch. If we walked the table wrongly before, we
will retry the access.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Update few code paths to check for pmd_large.
set_pmd_at:
We want to use this to store swap pte at pmd level. For swap ptes we don't want
to set H_PAGE_THP_HUGE. Hence check for pmd_large in set_pmd_at. This remove
the false WARN_ON when using this with swap pmd entry.
pmd_page:
We don't really use them on pmd migration entries. But they can also work with
migration entries and we don't differentiate at the pte level. Hence update
pmd_page to work with pmd migration entries too
__find_linux_pte:
lockless page table walk need to handle pmd migration entries. pmd_trans_huge
check will return false on them. We don't set thp = 1 for such entries, but
update hpage_shift correctly. Without this we will walk pmd migration entries
as a pte page pointer which is wrong.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This make hugetlb directory pointer similar to other page able entries. A hugepd
entry is identified by lack of _PAGE_PTE bit set and directory size stored in
HUGEPD_SHIFT_MASK. We update that to also look at _PAGE_PRESENT
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With this patch we use 0x8000000000000000UL (_PAGE_PRESENT) to indicate a valid
pgd/pud/pmd entry. We also switch the p**_present() to look at this bit.
With pmd_present, we have a special case. We need to make sure we consider a
pmd marked invalid during THP split as present. Right now we clear the
_PAGE_PRESENT bit during a pmdp_invalidate. Inorder to consider this special
case we add a new pte bit _PAGE_INVALID (mapped to _RPAGE_SW0). This bit is
only used with _PAGE_PRESENT cleared. Hence we are not really losing a pte bit
for this special case. pmd_present is also updated to look at _PAGE_INVALID.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Ever since fast reboot is enabled by default in opal,
opal_cec_reboot() will use fast-reset instead of full IPL to perform
system reboot. This leaves the user with no direct way to force a full
IPL reboot except changing an nvram setting that persistently disables
fast-reset for all subsequent reboots.
This patch provides a more direct way for the user to force a one-shot
full IPL reboot by passing the command line argument 'full' to the
reboot command. So the user will be able to tweak the reboot behavior
via:
$ sudo reboot full # Force a full ipl reboot skipping fast-reset
or
$ sudo reboot # default reboot path (usually fast-reset)
The reboot command passes the un-parsed command argument to the kernel
via the 'Reboot' syscall which is then passed on to the arch function
pnv_restart(). The patch updates pnv_restart() to handle this cmd-arg
and issues opal_cec_reboot2 with OPAL_REBOOT_FULL_IPL to force a full
IPL reset.
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In power7_marked_instr_event() there is a switch case that is missing
a break or an explicit fallthrough, it's not immediately clear which
it should be.
The function determines based on the PMU event code, whether the event
is a "marked" event (which then requires us to configure the PMU in a
certain way). On Power7 there is no specific bit(s) in the event to
tell us that, we just have to know.
Rather than having a full list of every event and whether they are
marked, we pull apart the event code and for events with certain
values of certain fields we can say that those are all marked events.
We take the psel (bits 0-7) of the event, and look at bits 4-7. For a
value of 6 we say that if the entire psel == 0x64 then if the pmc == 3
the event is marked, else not, and otherwise we continue.
It is then that we fallthrough to the 8 case, where we return true if
the unit == 0xd.
The question is should the 6 case also fallthrough and check for
unit == 0xd, or should it return.
Looking at the full list of events we see that there are zero events
where (psel >> 4) == 0x6 and unit == 0xd.
So the answer is it doesn't really matter, there are no valid event
codes that will return a different result whether we fallthrough or
break.
But equally, testing the 6 case events against unit == 0xd is slightly
bogus, as there are no such events. So to make the code clearer, and
avoid any future confusion, have the 6 case break rather than falling
through.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
This reverts commits:
5e46e29e6a ("powerpc/64s/hash: convert SLB miss handlers to C")
8fed04d0f6 ("powerpc/64s/hash: remove user SLB data from the paca")
655deecf67 ("powerpc/64s/hash: SLB allocation status bitmaps")
2e1626744e ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup")
89ca4e126a ("powerpc/64s/hash: Add a SLB preload cache")
This series had a few bugs, and the fixes are not all trivial. So
revert most of it for now.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add the ISO7816 ioctl and associated accessors and data structure.
Drivers can then use this common implementation to handle ISO7816
(smart cards).
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable the 'dtbs' target for powerpc. This allows building all the dts
files in arch/powerpc/boot/dts/ when COMPILE_TEST and OF_ALL_DTBS are
enabled.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
There is nothing arch specific about building dtb files other than their
location under /arch/*/boot/dts/. Keeping each arch aligned is a pain.
The dependencies and supported targets are all slightly different.
Also, a cross-compiler for each arch is needed, but really the host
compiler preprocessor is perfectly fine for building dtbs. Move the
build rules to a common location and remove the arch specific ones. This
is done in a single step to avoid warnings about overriding rules.
The build dependencies had been a mixture of 'scripts' and/or 'prepare'.
These pull in several dependencies some of which need a target compiler
(specifically devicetable-offsets.h) and aren't needed to build dtbs.
All that is really needed is dtc, so adjust the dependencies to only be
dtc.
This change enables support 'dtbs_install' on some arches which were
missing the target.
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Paul Burton <paul.burton@mips.com>
Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-kbuild@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-mips@linux-mips.org
Cc: nios2-dev@lists.rocketboards.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-xtensa@linux-xtensa.org
Signed-off-by: Rob Herring <robh@kernel.org>
Align powerpc with other architectures which build the dtb files in the
same directory as the dts files. This is also in line with most other
build targets which are located in the same directory as the source.
This move will help enable the 'dtbs' target which builds all the dtbs
regardless of kernel config.
This transition could break some scripts if they expect dtb files in the
old location.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
Commit 51c3c62b58 ("powerpc: Avoid code patching freed init
sections") accesses 'init_mem_is_free' flag too early, before the
kernel is relocated. This provokes early boot failure (before the
console is active).
As it is not necessary to do this verification that early, this
patch moves the test into patch_instruction() instead of
__patch_instruction().
This modification also has the advantage of avoiding unnecessary
remappings.
Fixes: 51c3c62b58 ("powerpc: Avoid code patching freed init sections")
Cc: stable@vger.kernel.org # 4.13+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We return H_TOO_HARD from TCE update handlers when we think that
the next handler (realmode -> virtual mode -> user mode) has a chance to
handle the request; H_HARDWARE/H_CLOSED otherwise.
This changes the handlers to return H_TOO_HARD on every error giving
the userspace an opportunity to handle any request or at least log
them all.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The KVM TCE handlers are written in a way so they fail when either
something went horribly wrong or the userspace did some obvious mistake
such as passing a misaligned address.
We are going to enhance the TCE checker to fail on attempts to map bigger
IOMMU page than the underlying pinned memory so let's valitate TCE
beforehand.
This should cause no behavioral change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Introduce xarray value entries and tagged pointers to replace radix
tree exceptional entries. This is a slight change in encoding to allow
the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a
value entry). It is also a change in emphasis; exceptional entries are
intimidating and different. As the comment explains, you can choose
to store values or pointers in the xarray and they are both first-class
citizens.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
A reasonably big batch of fixes due to me being away for a few weeks.
A fix for the TM emulation support on Power9, which could result in corrupting
the guest r11 when running under KVM.
Two fixes to the TM code which could lead to userspace GPR corruption if we take
an SLB miss at exactly the wrong time.
Our dynamic patching code had a bug that meant we could patch freed __init text,
which could lead to corrupting userspace memory.
csum_ipv6_magic() didn't work on little endian platforms since we optimised it
recently.
A fix for an endian bug when reading a device tree property telling us how many
storage keys the machine has available.
Fix a crash seen on some configurations of PowerVM when migrating the partition
from one machine to another.
A fix for a regression in the setup of our CPU to NUMA node mapping in KVM
guests.
A fix to our selftest Makefiles to make them work since a recent change to the
shared Makefile logic.
Thanks to:
Alexey Kardashevskiy, Breno Leitao, Christophe Leroy, Michael Bringmann,
Michael Neuling, Nicholas Piggin, Paul Mackerras,, Srikar Dronamraju, Thiago
Jung Bauermann, Xin Long.
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Merge tag 'powerpc-4.19-3' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Michael writes:
"powerpc fixes for 4.19 #3
A reasonably big batch of fixes due to me being away for a few weeks.
A fix for the TM emulation support on Power9, which could result in
corrupting the guest r11 when running under KVM.
Two fixes to the TM code which could lead to userspace GPR corruption
if we take an SLB miss at exactly the wrong time.
Our dynamic patching code had a bug that meant we could patch freed
__init text, which could lead to corrupting userspace memory.
csum_ipv6_magic() didn't work on little endian platforms since we
optimised it recently.
A fix for an endian bug when reading a device tree property telling
us how many storage keys the machine has available.
Fix a crash seen on some configurations of PowerVM when migrating the
partition from one machine to another.
A fix for a regression in the setup of our CPU to NUMA node mapping
in KVM guests.
A fix to our selftest Makefiles to make them work since a recent
change to the shared Makefile logic."
* tag 'powerpc-4.19-3' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Fix Makefiles for headers_install change
powerpc/numa: Use associativity if VPHN hcall is successful
powerpc/tm: Avoid possible userspace r1 corruption on reclaim
powerpc/tm: Fix userspace r13 corruption
powerpc/pseries: Fix unitialized timer reset on migration
powerpc/pkeys: Fix reading of ibm, processor-storage-keys property
powerpc: fix csum_ipv6_magic() on little endian platforms
powerpc/powernv/ioda2: Reduce upper limit for DMA window size (again)
powerpc: Avoid code patching freed init sections
KVM: PPC: Book3S HV: Fix guest r11 corruption with POWER9 TM workarounds
"device_type" use is deprecated for FDT though it has continued to be used
for nodes like cpu nodes. Use of_get_cpu_node() instead which works using
node names by default. This will allow the eventually removal of cpu
device_type properties.
Also, fix a leaked reference and add a missing of_node_put.
Cc: Vitaly Bordug <vitb@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
"device_type" use is deprecated for FDT though it has continued to be used
for nodes like cpu nodes. Use of_get_cpu_node() instead which works using
node names by default. This will allow the eventually removal of cpu
device_type properties.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
Use the for_each_of_cpu_node iterator to iterate over cpu nodes. This
has the side effect of defaulting to iterating using "cpu" node names in
preference to the deprecated (for FDT) device_type == "cpu".
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
Current we store the userspace r1 to PACATMSCRATCH before finally
saving it to the thread struct.
In theory an exception could be taken here (like a machine check or
SLB miss) that could write PACATMSCRATCH and hence corrupt the
userspace r1. The SLB fault currently doesn't touch PACATMSCRATCH, but
others do.
We've never actually seen this happen but it's theoretically
possible. Either way, the code is fragile as it is.
This patch saves r1 to the kernel stack (which can't fault) before we
turn MSR[RI] back on. PACATMSCRATCH is still used but only with
MSR[RI] off. We then copy r1 from the kernel stack to the thread
struct once we have MSR[RI] back on.
Suggested-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we treclaim we store the userspace checkpointed r13 to a scratch
SPR and then later save the scratch SPR to the user thread struct.
Unfortunately, this doesn't work as accessing the user thread struct
can take an SLB fault and the SLB fault handler will write the same
scratch SPRG that now contains the userspace r13.
To fix this, we store r13 to the kernel stack (which can't fault)
before we access the user thread struct.
Found by running P8 guest + powervm + disable_1tb_segments + TM. Seen
as a random userspace segfault with r13 looking like a kernel address.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
After migration of a powerpc LPAR, the kernel executes code to
update the system state to reflect new platform characteristics.
Such changes include modifications to device tree properties provided
to the system by PHYP. Property notifications received by the
post_mobility_fixup() code are passed along to the kernel in general
through a call to of_update_property() which in turn passes such
events back to all modules through entries like the '.notifier_call'
function within the NUMA module.
When the NUMA module updates its state, it resets its event timer. If
this occurs after a previous call to stop_topology_update() or on a
system without VPHN enabled, the code runs into an unitialized timer
structure and crashes. This patch adds a safety check along this path
toward the problem code.
An example crash log is as follows.
ibmvscsi 30000081: Re-enabling adapter!
------------[ cut here ]------------
kernel BUG at kernel/time/timer.c:958!
Oops: Exception in kernel mode, sig: 5 [#1]
LE SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: nfsv3 nfs_acl nfs tcp_diag udp_diag inet_diag lockd unix_diag af_packet_diag netlink_diag grace fscache sunrpc xts vmx_crypto pseries_rng sg binfmt_misc ip_tables xfs libcrc32c sd_mod ibmvscsi ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod
CPU: 11 PID: 3067 Comm: drmgr Not tainted 4.17.0+ #179
...
NIP mod_timer+0x4c/0x400
LR reset_topology_timer+0x40/0x60
Call Trace:
0xc0000003f9407830 (unreliable)
reset_topology_timer+0x40/0x60
dt_update_callback+0x100/0x120
notifier_call_chain+0x90/0x100
__blocking_notifier_call_chain+0x60/0x90
of_property_notify+0x90/0xd0
of_update_property+0x104/0x150
update_dt_property+0xdc/0x1f0
pseries_devicetree_update+0x2d0/0x510
post_mobility_fixup+0x7c/0xf0
migration_store+0xa4/0xc0
kobj_attr_store+0x30/0x60
sysfs_kf_write+0x64/0xa0
kernfs_fop_write+0x16c/0x240
__vfs_write+0x40/0x200
vfs_write+0xc8/0x240
ksys_write+0x5c/0x100
system_call+0x58/0x6c
Fixes: 5d88aa85c0 ("powerpc/pseries: Update CPU maps when device tree is updated")
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Call force_sig_pkuerr directly instead of rolling it by hand
in _exception_pkey.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that _exception no longer calls _exception_pkey it is no longer
necessary to handle any signal with any si_code. All pkey exceptions
are SIGSEGV with paired with SEGV_PKUERR. So just handle
that case and remove the now unnecessary parameters from _exception_pkey.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The callers of _exception don't need the pkey exception logic because
they are not processing a pkey exception. So just call exception_common
directly and then call force_sig_fault to generate the appropriate siginfo
and deliver the appropriate signal.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
It is brittle and wrong to populate si_pkey when there was not a pkey
exception. The field does not exist for all si_codes and in some
cases another field exists in the same memory location.
So factor out the code that all exceptions handlers must run
into exception_common, leaving the individual exception handlers
to generate the signals themselves.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that bad_key_fault_exception no longer calls __bad_area_nosemaphore
there is no reason for __bad_area_nosemaphore to handle pkeys.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This removes the need for other code paths to deal with pkey exceptions.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There are no callers of __bad_area that pass in a pkey parameter so it makes
no sense to take one.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In do_sigbus isolate the mceerr signaling code and call
force_sig_mceerr instead of falling through to the force_sig_info that
works for all of the other signals.
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
scan_pkey_feature() uses of_property_read_u32_array() to read the
ibm,processor-storage-keys property and calls be32_to_cpu() on the
value it gets. The problem is that of_property_read_u32_array() already
returns the value converted to the CPU byte order.
The value of pkeys_total ends up more or less sane because there's a min()
call in pkey_initialize() which reduces pkeys_total to 32. So in practice
the kernel ignores the fact that the hypervisor reserved one key for
itself (the device tree advertises 31 keys in my test VM).
This is wrong, but the effect in practice is that when a process tries to
allocate the 32nd key, it gets an -EINVAL error instead of -ENOSPC which
would indicate that there aren't any keys available
Fixes: cf43d3b264 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On little endian platforms, csum_ipv6_magic() keeps len and proto in
CPU byte order. This generates a bad results leading to ICMPv6 packets
from other hosts being dropped by powerpc64le platforms.
In order to fix this, len and proto should be converted to network
byte order ie bigendian byte order. However checksumming 0x12345678
and 0x56341278 provide the exact same result so it is enough to
rotate the sum of len and proto by 1 byte.
PPC32 only support bigendian so the fix is needed for PPC64 only
Fixes: e9c4943a10 ("powerpc: Implement csum_ipv6_magic in assembly")
Reported-by: Jianlin Shi <jishi@redhat.com>
Reported-by: Xin Long <lucien.xin@gmail.com>
Cc: <stable@vger.kernel.org> # 4.18+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
mpe: This was fixed originally in commit d3d4ffaae4
("powerpc/powernv/ioda2: Reduce upper limit for DMA window size"), but
contrary to what the merge commit says was inadvertently lost by me in
commit ce57c6610c ("Merge branch 'topic/ppc-kvm' into next") which
brought in changes that moved the code to a new file. So reapply it to
the new file.
Original commit message follows:
We use PHB in mode1 which uses bit 59 to select a correct DMA window.
However there is mode2 which uses bits 59:55 and allows up to 32 DMA
windows per a PE.
Even though documentation does not clearly specify that, it seems that
the actual hardware does not support bits 59:55 even in mode1, in
other words we can create a window as big as 1<<58 but DMA simply
won't work.
This reduces the upper limit from 59 to 55 bits to let the userspace
know about the hardware limits.
Fixes: ce57c6610c ("Merge branch 'topic/ppc-kvm' into next")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The next update of libfdt has a new dependency on INT_MAX. Update the
instances of libfdt_env.h in the kernel to either include the necessary
header with the definition or define it locally.
Cc: Russell King <linux@armlinux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
Replace user_single_step_siginfo with user_single_step_report
that allocates siginfo structure on the stack and sends it.
This allows tracehook_report_syscall_exit to become a simple
if statement that calls user_single_step_report or ptrace_report_syscall
depending on the value of step.
Update the default helper function now called user_single_step_report
to explicitly set si_code to SI_USER and to set si_uid and si_pid to 0.
The default helper has always been doing this (using memset) but it
was far from obvious.
The powerpc helper can now just call force_sig_fault.
The x86 helper can now just call send_sigtrap.
Unfortunately the default implementation of user_single_step_report
can not use force_sig_fault as it does not use a SIGTRAP si_code.
So it has to carefully setup the siginfo and use use force_sig_info.
The net result is code that is easier to understand and simpler
to maintain.
Ref: 85ec7fd9f8 ("ptrace: introduce user_single_step_siginfo() helper")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Firmware-Assisted Dump (FADump) needs to be registered again after any
memory hot add/remove operation to update the crash memory ranges. But
currently, the kernel returns '-EEXIST' if we try to register without
uregistering it first. This could expose the system to racing issues
while unregistering and registering FADump from userspace during udev
events. Spare the userspace of this and let it be taken care of in the
kernel space for a simpler interface.
Since this change, running 'echo 1 > /sys/kernel/fadump_registered'
would result in re-regisering (unregistering and registering) FADump,
if it was already registered.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In lparcfg_write we hard code kbuf_sz and then use this as the variable
length of kbuf creating a variable length array. Since we're hard coding
the length anyway just define the array using this as the length and
remove the need for kbuf_sz, thus removing the variable length array.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In prom_check_platform_support() we retrieve and parse the
"ibm,arch-vec-5-platform-support" property of the chosen node.
Currently we use a variable length array however to avoid this use an
array of constant length 8.
This property is used to indicate the supported options of vector 5
bytes 23-26 of the ibm,architecture.vec node. Each of these options
is a pair of bytes, thus for 4 options we have a max length of 8 bytes.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This re-applies commit b91c1e3e7a ("powerpc: Fix duplicate const
clang warning in user access code") (Jun 2015) which was undone in
commits:
f2ca809059 ("powerpc/sparse: Constify the address pointer in __get_user_nosleep()") (Feb 2017)
d466f6c5ca ("powerpc/sparse: Constify the address pointer in __get_user_nocheck()") (Feb 2017)
f84ed59a61 ("powerpc/sparse: Constify the address pointer in __get_user_check()") (Feb 2017)
We see a large number of duplicate const errors in the user access
code when building with llvm/clang:
include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
ret = __get_user(c, uaddr);
The problem is we are doing const __typeof__(*(ptr)), which will hit
the warning if ptr is marked const.
Removing const does not seem to have any effect on GCC code
generation.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When building with clang crt0's _zimage_start is not marked weak, which
breaks the build when linking the kernel image:
$ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
0000000000000058 g .text 0000000000000000 _zimage_start
ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start':
(.text+0x58): multiple definition of '_zimage_start';
arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here
Clang requires the .weak directive to appear after the symbol is
declared. The binutils manual says:
This directive sets the weak attribute on the comma separated list of
symbol names. If the symbols do not already exist, they will be
created.
So it appears this is different with clang. The only reference I could
see for this was an OpenBSD mailing list post[1].
Changing it to be after the declaration fixes building with Clang, and
still works with GCC.
$ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
0000000000000058 w .text 0000000000000000 _zimage_start
Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921
[1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Disable new features from recent releases, and clean out some other
unused options:
- Enable EXPERT, so we can disable some things
- Disable non-powerpc BPF decoders
- Disable TASKSTATS
- Disable unused syscalls
- Set more things to be modules
- Turn off unused network vendors
- PPC_OF_BOOT_TRAMPOLINE and FB_OF are unused on powernv
- Drop unused Radeon and Matrox GPU drivers
- IPV6 support landed in petitboot
- Bringup related command line powersave=off dropped, switch to quiet
Set CONFIG_I2C_CHARDEV=y as the module is not loaded automatically, and
without this i2cget etc. will fail in the skiroot environment.
This defconfig gets us build coverage of KERNEL_XZ, which was broken in
the 4.19 merge window for powerpc.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When performing partition migrations all present CPUs must be online
as all present CPUs must make the H_JOIN call as part of the migration
process. Once all present CPUs make the H_JOIN call, one CPU is returned
to make the rtas call to perform the migration to the destination system.
During testing of migration and changing the SMT state we have found
instances where CPUs are offlined, as part of the SMT state change,
before they make the H_JOIN call. This results in a hung system where
every CPU is either in H_JOIN or offline.
To prevent this this patch disables CPU hotplug during the migration
process.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are three instances in which dlpar hotplug events are invoked;
handling a hotplug interrupt (in a kvm guest), handling a dlpar
request through sysfs, and updating LMB affinity when handling a
PRRN event. Only in the case of handling a hotplug interrupt do we
have to put the work on a workqueue, the other cases can handle the
dlpar request directly.
This patch exports the handle_dlpar_errorlog() function so that
dlpar hotplug events can be handled directly and updates the two
instances mentioned above to use the direct invocation.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The updates to powerpc numa and memory hotplug code now use the
in-kernel LMB array instead of the device tree. This change allows the
pseries memory DLPAR code to only update the device tree once after
successfully handling a DLPAR request.
Prior to the in-kernel LMB array, the numa code looked up the affinity
for memory being added in the device tree, the code now looks this up
in the LMB array. This change means the memory hotplug code can just
update the affinity for an LMB in the LMB array instead of updating
the device tree.
This also provides a savings in kernel memory. When updating the
device tree old properties are never free'ed since there is no
usecount on properties. This behavior leads to a new copy of the
property being allocated every time a LMB is added or removed (i.e. a
request to add 100 LMBs creates 100 new copies of the property). With
this update only a single new property is created when a DLPAR request
completes successfully.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
GCC 4.6 is the minimum supported now.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When switching processes, currently all user SLBEs are cleared, and a
few (exec_base, pc, and stack) are preloaded. In trivial testing with
small apps, this tends to miss the heap and low 256MB segments, and it
will also miss commonly accessed segments on large memory workloads.
Add a simple round-robin preload cache that just inserts the last SLB
miss into the head of the cache and preloads those at context switch
time. Every 256 context switches, the oldest entry is removed from the
cache to shrink the cache and require fewer slbmte if they are unused.
Much more could go into this, including into the SLB entry reclaim
side to track some LRU information etc, which would require a study of
large memory workloads. But this is a simple thing we can do now that
is an obvious win for common workloads.
With the full series, process switching speed on the context_switch
benchmark on POWER9/hash (with kernel speculation security masures
disabled) increases from 140K/s to 178K/s (27%).
POWER8 does not change much (within 1%), it's unclear why it does not
see a big gain like POWER9.
Booting to busybox init with 256MB segments has SLB misses go down
from 945 to 69, and with 1T segments 900 to 21. These could almost all
be eliminated by preloading a bit more carefully with ELF binary
loading.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add 32-entry bitmaps to track the allocation status of the first 32
SLB entries, and whether they are user or kernel entries. These are
used to allocate free SLB entries first, before resorting to the round
robin allocator.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
User SLB mappig data is copied into the PACA from the mm->context so
it can be accessed by the SLB miss handlers.
After the C conversion, SLB miss handlers now run with relocation on,
and user SLB misses are able to take recursive kernel SLB misses, so
the user SLB mapping data can be removed from the paca and accessed
directly.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch moves SLB miss handlers completely to C, using the standard
exception handler macros to set up the stack and branch to C.
This can be done because the segment containing the kernel stack is
always bolted, so accessing it with relocation on will not cause an
SLB exception.
Arbitrary kernel memory may not be accessed when handling kernel space
SLB misses, so care should be taken there. However user SLB misses can
access any kernel memory, which can be used to move some fields out of
the paca (in later patches).
User SLB misses could quite easily reconcile IRQs and set up a first
class kernel environment and exit via ret_from_except, however that
doesn't seem to be necessary at the moment, so we only do that if a
bad fault is encountered.
[ Credit to Aneesh for bug fixes, error checks, and improvements to bad
address handling, etc ]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Since RFC:
- Added MSR[RI] handling
- Fixed up a register loss bug exposed by irq tracing (Aneesh)
- Reject misses outside the defined kernel regions (Aneesh)
- Added several more sanity checks and error handling (Aneesh), we may
look at consolidating these tests and tightenig up the code but for
a first pass we decided it's better to check carefully.
Since v1:
- Fixed SLB cache corruption (Aneesh)
- Fixed untidy SLBE allocation "leak" in get_vsid error case
- Now survives some stress testing on real hardware
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 introduces SLBIA IH=3, which invalidates all SLB entries and
associated lookaside information that have a class value of 1, which
Linux assigns to user addresses. This matches what switch_slb wants,
and allows a simple fast implementation that avoids the slb_cache
complexity.
As a side-effect, the POWER5 < DD2.1 SLB invalidation workaround is
also avoided on POWER9.
Process context switching rate is improved about 2.2% for a small
process that hits the slb cache which is the best case for the current
code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The SLBIA IH=1 hint will remove all non-zero SLBEs, but only
invalidate ERAT entries associated with a class value of 1, for
processors that support the hint (e.g., POWER6 and newer), which
Linux assigns to user addresses.
This prevents kernel ERAT entries from being invalidated when
context switchig (if the thread faulted in more than 8 user SLBEs).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove the vmalloc segment from bolted SLBEs. This is not required to
be bolted, and seems like it was added to help pre-load the SLB on
context switch. However there are now other segments like the vmemmap
segment and non-zero node memory that often take misses after a context
switch, so it is better to solve this in a more general way.
A subsequent change will track free SLB entries and uses those rather
than round-robin overwrite valid entries, which makes it far less
likely for kernel SLBEs to be evicted after they are installed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The POWER5 < DD2.1 issue is that slbie needs to be issued more than
once. It came in with this change:
ChangeSet@1.1608, 2004-04-29 07:12:31-07:00, david@gibson.dropbear.id.au
[PATCH] POWER5 erratum workaround
Early POWER5 revisions (<DD2.1) have a problem requiring slbie
instructions to be repeated under some circumstances. The patch below
adds a workaround (patch made by Anton Blanchard).
(aka. 3e4520f7605243abf66a7ccd3d2e49e48e8c0483 in the full history tree)
The extra slbie in switch_slb is done even for the case where slbia is
called (slb_flush_and_rebolt). I don't believe that is required
because there are other slb_flush_and_rebolt callers which do not
issue the workaround slbie, which would be broken if it was required.
It also seems to be fine inside the isync with the first slbie, as it
is in the kernel stack switch code.
So move this workaround to where it is required. This is not much of
an optimisation because this is the fast path, but it makes the code
more understandable and neater.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain slbie_data initialisation to avoid compiler warning]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
I only have POWER8/9 to test, so just remove it for those.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This causes SLB alloation to start 1 beyond the start of the SLB.
There is no real problem because after it wraps it stats behaving
properly, it's just surprisig to see when looking at SLB traces.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that other platforms also implements real mode mce handler,
lets consolidate the code by sharing existing powernv machine check
early code. Rename machine_check_powernv_early to
machine_check_common_early and reuse the code.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Extract the MCE error details from RTAS extended log and display it to
console.
With this patch you should now see mce logs like below:
[ 142.371818] Severe Machine check interrupt [Recovered]
[ 142.371822] NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel]
[ 142.371822] Initiator: CPU
[ 142.371823] Error type: SLB [Multihit]
[ 142.371824] Effective address: d00000000ca70000
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On pseries, as of today system crashes if we get a machine check
exceptions due to SLB errors. These are soft errors and can be fixed
by flushing the SLBs so the kernel can continue to function instead of
system crash. We do this in real mode before turning on MMU. Otherwise
we would run into nested machine checks. This patch now fetches the
rtas error log in real mode and flushes the SLBs on SLB/ERAT errors.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On pseries, the machine check error details are part of RTAS extended
event log passed under Machine check exception section. This patch adds
the definition of rtas MCE event section and related helper
functions.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check
if it is not NULL.
Just moving the dereference code to after the check, where there will
be guarantee that 'tbl' will not be NULL.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Function xive_native_get_ipi() might use chip_id without it being
initialized, if the CPU node is not found, as reported by smatch:
error: uninitialized symbol 'chip_id'
As suggested by Cédric, we can use xc->chip_id instead of consulting
the device tree for chip id, which is safe since xive_prepare_cpu()
should have initialized ->chip_id by the time xive_native_get_ipi() is
called.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[mpe: Tweak change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When hot-removing memory release_mem_region_adjustable() splits iomem
resources if they are not the exact size of the memory being
hot-deleted. Adding this memory back to the kernel adds a new resource.
Eg a node has memory 0x0 - 0xfffffffff. Hot-removing 1GB from
0xf40000000 results in the single resource 0x0-0xfffffffff being split
into two resources: 0x0-0xf3fffffff and 0xf80000000-0xfffffffff.
When we hot-add the memory back we now have three resources:
0x0-0xf3fffffff, 0xf40000000-0xf7fffffff, and 0xf80000000-0xfffffffff.
This is an issue if we try to remove some memory that overlaps
resources. Eg when trying to remove 2GB at address 0xf40000000,
release_mem_region_adjustable() fails as it expects the chunk of memory
to be within the boundaries of a single resource. We then get the
warning: "Unable to release resource" and attempting to use memtrace
again gives us this error: "bash: echo: write error: Resource
temporarily unavailable"
This patch makes memtrace remove memory in chunks that are always the
same size from an address that is always equal to end_of_memory -
n*size, for some n. So hotremoving and hotadding memory of different
sizes will now not attempt to remove memory that spans multiple
resources.
Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Ever since the PCI hotplug core was introduced in 2002, drivers had to
allocate and register a struct hotplug_slot_info for every slot:
https://git.kernel.org/tglx/history/c/a8a2069f432c
Apparently the idea was that drivers furnish the hotplug core with an
up-to-date card presence status, power status, latch status and
attention indicator status as well as notify the hotplug core of changes
thereof. However only 4 out of 12 hotplug drivers bother to notify the
hotplug core with pci_hp_change_slot_info() and the hotplug core never
made any use of the information: There is just a single macro in
pci_hotplug_core.c, GET_STATUS(), which uses the hotplug_slot_info if
the driver lacks the corresponding callback in hotplug_slot_ops. The
macro is called when the user reads the attribute via sysfs.
Now, if the callback isn't defined, the attribute isn't exposed in sysfs
in the first place (see e.g. has_power_file()). There are only two
situations when the hotplug_slot_info would actually be accessed:
* If the driver defines ->enable_slot or ->disable_slot but not
->get_power_status.
* If the driver defines ->set_attention_status but not
->get_attention_status.
There is no driver doing the former and just a single driver doing the
latter, namely pnv_php.c. Amend it with a ->get_attention_status
callback. With that, the hotplug_slot_info becomes completely unused by
the PCI hotplug core. But a few drivers use it internally as a cache:
cpcihp uses it to cache the latch_status and adapter_status.
cpqhp uses it to cache the adapter_status.
pnv_php and rpaphp use it to cache the attention_status.
shpchp uses it to cache all four values.
Amend these drivers to cache the information in their private slot
struct. shpchp's slot struct already contains members to cache the
power_status and adapter_status, so additional members are only needed
for the other two values. In the case of cpqphp, the cached value is
only accessed in a single place, so instead of caching it, read the
current value from the hardware.
Caution: acpiphp, cpci, cpqhp, shpchp, asus-wmi and eeepc-laptop
populate the hotplug_slot_info with initial values on probe. That code
is herewith removed. There is a theoretical chance that the code has
side effects without which the driver fails to function, e.g. if the
ACPI method to read the adapter status needs to be executed at least
once on probe. That seems unlikely to me, still maintainers should
review the changes carefully for this possibility.
Rafael adds: "I'm not aware of any case in which it will break anything,
[...] but if that happens, it may be necessary to add the execution of
the control methods in question directly to the initialization part."
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> # drivers/pci/hotplug/rpa*
Acked-by: Sebastian Ott <sebott@linux.ibm.com> # drivers/pci/hotplug/s390*
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # drivers/platform/x86
Cc: Len Brown <lenb@kernel.org>
Cc: Scott Murray <scott@spiteful.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Gavin Shan <gwshan@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Corentin Chary <corentin.chary@gmail.com>
Cc: Darren Hart <dvhart@infradead.org>
This stops us from doing code patching in init sections after they've
been freed.
In this chain:
kvm_guest_init() ->
kvm_use_magic_page() ->
fault_in_pages_readable() ->
__get_user() ->
__get_user_nocheck() ->
barrier_nospec();
We have a code patching location at barrier_nospec() and
kvm_guest_init() is an init function. This whole chain gets inlined,
so when we free the init section (hence kvm_guest_init()), this code
goes away and hence should no longer be patched.
We seen this as userspace memory corruption when using a memory
checker while doing partition migration testing on powervm (this
starts the code patching post migration via
/sys/kernel/mobility/migration). In theory, it could also happen when
using /sys/kernel/debug/powerpc/barrier_nospec.
Cc: stable@vger.kernel.org # 4.13+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Static branch hints override dynamic branch prediction on recent
POWER CPUs. We should only use them when we are overwhelmingly
sure of the direction.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This hypervisor's call allows to remove up to 8 ptes with only call to
tlbie.
The virtual pages must be all within the same naturally aligned 8 pages
virtual address block and have the same page and segment size encodings.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This part of code will be called also when dealing with H_BLOCK_REMOVE.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This feature tells if the hcall H_BLOCK_REMOVE is available.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch simply fix part of the documentation on the HTM code.
This fixes reference to old fields that were renamed in commit
000ec280e3 ("powerpc: tm: Rename transct_(*) to ck(\1)_state")
It also documents better the flow after commit eb5c3f1c86 ("powerpc:
Always save/restore checkpointed regs during treclaim/trecheckpoint"),
where tm_recheckpoint can recheckpoint what is in ck{fp,vr}_state
blindly.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
