Currently emulator returns -1 when emulation failed or IO is needed.
Caller tries to guess whether emulation failed by looking at other
variables. Make it easier for caller to recognise error condition by
always returning -1 in case of failure. For this new emulator
internal return value X86EMUL_IO_NEEDED is introduced. It is used to
distinguish between error condition (which returns X86EMUL_UNHANDLEABLE)
and condition that requires IO exit to userspace to continue emulation.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Fill in run->mmio details in (read|write)_emulated function just like
pio does. There is no point in filling only vcpu fields there just to
copy them into vcpu->run a little bit later.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently X86EMUL_PROPAGATE_FAULT, X86EMUL_RETRY_INSTR and
X86EMUL_CMPXCHG_FAILED have the same value so caller cannot
distinguish why function such as emulator_cmpxchg_emulated()
(which can return both X86EMUL_PROPAGATE_FAULT and
X86EMUL_CMPXCHG_FAILED) failed.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Make (get|set)_dr() callback return error if it fails instead of
injecting exception behind emulator's back.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Make set_cr() callback return error if it fails instead of injecting #GP
behind emulator's back.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Use callbacks from x86_emulate_ops to access segments instead of calling
into kvm directly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
On VMX it is expensive to call get_cached_descriptor() just to get segment
base since multiple vmcs_reads are done instead of only one. Introduce
new call back get_cached_segment_base() for efficiency.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Add (set|get)_msr callbacks to x86_emulate_ops instead of calling
them directly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Add (set|get)_dr callbacks to x86_emulate_ops instead of calling
them directly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
ljmp/lcall instruction operand contains address and segment.
It can be 10 bytes long. Currently we decode it as two different
operands. Fix it by introducing new kind of operand that can hold
entire far address.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Dst operand is already initialized during decoding stage. No need to
reinitialize.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This instruction does not need generic decoding for its dst operand.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce read cache which is needed for instruction that require more
then one exit to userspace. After returning from userspace the instruction
will be re-executed with cached read value.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
cr0.ts may change between entries, so we copy cr0 to HOST_CR0 before each
entry. That is slow, so instead, set HOST_CR0 to have TS set unconditionally
(which is a safe value), and issue a clts() just before exiting vcpu context
if the task indeed owns the fpu.
Saves ~50 cycles/exit.
Signed-off-by: Avi Kivity <avi@redhat.com>
Although we always allocate a new dirty bitmap in x86's get_dirty_log(),
it is only used as a zero-source of copy_to_user() and freed right after
that when memslot is clean. This patch uses clear_user() instead of doing
this unnecessary zero-source allocation.
Performance improvement: as we can expect easily, the time needed to
allocate a bitmap is completely reduced. In my test, the improved ioctl
was about 4 to 10 times faster than the original one for clean slots.
Furthermore, reducing memory allocations and copies will produce good
effects to caches too.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
In common cases, guest SRAO MCE will cause corresponding poisoned page
be un-mapped and SIGBUS be sent to QEMU-KVM, then QEMU-KVM will relay
the MCE to guest OS.
But it is reported that if the poisoned page is accessed in guest
after unmapping and before MCE is relayed to guest OS, userspace will
be killed.
The reason is as follows. Because poisoned page has been un-mapped,
guest access will cause guest exit and kvm_mmu_page_fault will be
called. kvm_mmu_page_fault can not get the poisoned page for fault
address, so kernel and user space MMIO processing is tried in turn. In
user MMIO processing, poisoned page is accessed again, then userspace
is killed by force_sig_info.
To fix the bug, kvm_mmu_page_fault send HWPOISON signal to QEMU-KVM
and do not try kernel and user space MMIO processing for poisoned
page.
[xiao: fix warning introduced by avi]
Reported-by: Max Asbock <masbock@linux.vnet.ibm.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
HW breakpoints events stopped working correctly with kgdb
as a result of commit: 018cbffe68
(Merge commit 'v2.6.33' into perf/core).
The regression occurred because the behavior changed for setting
NOTIFY_STOP as the return value to the die notifier if the breakpoint
was known to the HW breakpoint API. Because kgdb is using the HW
breakpoint API to register HW breakpoints slots, it must also now
implement the overflow_handler call back else kgdb does not get to see
the events from the die notifier.
The kgdb_ll_trap function will be changed to be general purpose code
which can allow an easy way to implement the hw_breakpoint API
overflow call back.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Do not try to disable hpet if it hasn't been initialized before
x86, i8259: Only register sysdev if we have a real 8259 PIC
The Pstate transition latency check was added for broken F10h BIOSen
which wrongly contain a value of 0 for transition and bus master
latency. Fam11h and later, however, (will) have similar transition
latency so extend that behavior for them too.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The PCC cpufreq driver unmaps the mailbox address range if any CPUs fail to
initialise, but doesn't do anything to remove the registered CPUs from the
cpufreq core resulting in failures further down the line. We're better off
simply returning a failure - the cpufreq core will unregister us cleanly if
we end up with no successfully registered CPUs. Tidy up the failure path
and also add a sanity check to ensure that the firmware gives us a realistic
frequency - the core deals badly with that being set to 0.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The pcc specification documents an _OSC method that's incompatible with the
one defined as part of the ACPI spec. This shouldn't be a problem as both
are supposed to be guarded with a UUID. Unfortunately approximately nobody
(including HP, who wrote this spec) properly check the UUID on entry to the
_OSC call. Right now this could result in surprising behaviour if the pcc
driver performs an _OSC call on a machine that doesn't implement the pcc
specification. Check whether the PCCH method exists first in order to reduce
this probability.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Signed-off-by: Dave Jones <davej@redhat.com>
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: Use kmalloc() instead of vmalloc() for KVM_[GS]ET_MSR
KVM: MMU: fix conflict access permissions in direct sp
Commit 2a6b69765a
(ACPI: Store NVS state even when entering suspend to RAM) caused the
ACPI suspend code save the NVS area during suspend and restore it
during resume unconditionally, although it is known that some systems
need to use acpi_sleep=s4_nonvs for hibernation to work. To allow
the affected systems to avoid saving and restoring the NVS area
during suspend to RAM and resume, introduce kernel command line
option acpi_sleep=nonvs and make acpi_sleep=s4_nonvs work as its
alias temporarily (add acpi_sleep=s4_nonvs to the feature removal
file).
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16396 .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: tomas m <tmezzadra@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
hpet_disable is called unconditionally on machine reboot if hpet support
is compiled in the kernel.
hpet_disable only checks if the machine is hpet capable but doesn't make
sure that hpet has been initialized.
[ tglx: Made it a one liner and removed the redundant hpet_address check ]
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <alpine.DEB.2.00.1007211726240.22235@kaball-desktop>
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In no-direct mapping, we mark sp is 'direct' when we mapping the
guest's larger page, but its access is encoded form upper page-struct
entire not include the last mapping, it will cause access conflict.
For example, have this mapping:
[W]
/ PDE1 -> |---|
P[W] | | LPA
\ PDE2 -> |---|
[R]
P have two children, PDE1 and PDE2, both PDE1 and PDE2 mapping the
same lage page(LPA). The P's access is WR, PDE1's access is WR,
PDE2's access is RO(just consider read-write permissions here)
When guest access PDE1, we will create a direct sp for LPA, the sp's
access is from P, is W, then we will mark the ptes is W in this sp.
Then, guest access PDE2, we will find LPA's shadow page, is the same as
PDE's, and mark the ptes is RO.
So, if guest access PDE1, the incorrect #PF is occured.
Fixed by encode the last mapping access into direct shadow page
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
It turns out that there is a bit in the _CST for Intel FFH C3
that tells the OS if we should be checking BM_STS or not.
Linux has been unconditionally checking BM_STS.
If the chip-set is configured to enable BM_STS,
it can retard or completely prevent entry into
deep C-states -- as illustrated by turbostat:
http://userweb.kernel.org/~lenb/acpi/utils/pmtools/turbostat/
ref: Intel Processor Vendor-Specific ACPI Interface Specification
table 4 "_CST FFH GAS Field Encoding"
Bit 1: Set to 1 if OSPM should use Bus Master avoidance for this C-state
https://bugzilla.kernel.org/show_bug.cgi?id=15886
Signed-off-by: Len Brown <len.brown@intel.com>
In the CONFIG_AUDITSYSCALL fast-path for x86 64-bit system calls,
we can pass a bad return value and/or error indication for the
system call to audit_syscall_exit(). This happens when
TIF_NEED_RESCHED was set as the system call returned, so we went
out to schedule() and came back to the exit-audit fast-path. The
fix is to reload the user return value register from the pt_regs
before using it for audit_syscall_exit().
Both the 32-bit kernel's fast path and the 64-bit kernel's 32-bit
system call fast paths work slightly differently, so that they
always leave the fast path entirely to reschedule and don't return
there, so they don't have the analogous bugs.
Reported-by: Alexander Viro <aviro@redhat.com>
Signed-off-by: Roland McGrath <roland@redhat.com>
Pointed out by Lucas who found the new one in a comment in
setup_percpu.c. And then I fixed the others that I grepped
for.
Reported-by: Lucas <canolucas@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit e534c7c5f8 ("numa: x86_64: use generic percpu var
numa_node_id() implementation") broke numa systems that don't have ram
on node0 when MEMORY_HOTPLUG is enabled, because cpu_up() will call
cpu_to_node() before per_cpu(numa_node) is setup for APs.
When Node0 doesn't have RAM, on x86, cpus already round it to nearest
node with RAM in x86_cpu_to_node_map. and per_cpu(numa_node) is not set
up until in c_init for APs.
When later cpu_up() calling cpu_to_node() will get 0 again, and make it
online even there is no RAM on node0. so later all APs can not booted up,
and later will have panic.
[ 1.611101] On node 0 totalpages: 0
.........
[ 2.608558] On node 0 totalpages: 0
[ 2.612065] Brought up 1 CPUs
[ 2.615199] Total of 1 processors activated (3990.31 BogoMIPS).
...
93.225341] calling loop_init+0x0/0x1a4 @ 1
[ 93.229314] PERCPU: allocation failed, size=80 align=8, failed to populate
[ 93.246539] Pid: 1, comm: swapper Tainted: G W 2.6.35-rc4-tip-yh-04371-gd64e6c4-dirty #354
[ 93.264621] Call Trace:
[ 93.266533] [<ffffffff81125e43>] pcpu_alloc+0x83a/0x8e7
[ 93.270710] [<ffffffff81125f15>] __alloc_percpu+0x10/0x12
[ 93.285849] [<ffffffff8140786c>] alloc_disk_node+0x94/0x16d
[ 93.291811] [<ffffffff81407956>] alloc_disk+0x11/0x13
[ 93.306157] [<ffffffff81503e51>] loop_alloc+0xa7/0x180
[ 93.310538] [<ffffffff8277ef48>] loop_init+0x9b/0x1a4
[ 93.324909] [<ffffffff8277eead>] ? loop_init+0x0/0x1a4
[ 93.329650] [<ffffffff810001f2>] do_one_initcall+0x57/0x136
[ 93.345197] [<ffffffff827486d0>] kernel_init+0x184/0x20e
[ 93.348146] [<ffffffff81034954>] kernel_thread_helper+0x4/0x10
[ 93.365194] [<ffffffff81c7cc3c>] ? restore_args+0x0/0x30
[ 93.369305] [<ffffffff8274854c>] ? kernel_init+0x0/0x20e
[ 93.386011] [<ffffffff81034950>] ? kernel_thread_helper+0x0/0x10
[ 93.392047] loop: out of memory
...
Try to assign per_cpu(numa_node) early
[akpm@linux-foundation.org: tidy up code comment]
Signed-off-by: Yinghai <yinghai@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
My platform makes use of the null_legacy_pic choice and oopses when doing
a shutdown as the shutdown code goes through all the registered sysdevs
and calls their shutdown method which in my case poke on a non-existing
i8259. Imho the i8259 specific sysdev should only be registered if the
i8259 is actually there.
Do not register the sysdev function when the null_legacy_pic is used so
that the i8259 resume, suspend and shutdown functions are not called.
Signed-off-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
LKML-Reference: <201007202218.o6KMIJ3m020955@imap1.linux-foundation.org>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Cc: <stable@kernel.org> 2.6.34
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, pci, mrst: Add extra sanity check in walking the PCI extended cap chain
x86: Fix x2apic preenabled system with kexec
x86: Force HPET readback_cmp for all ATI chipsets
In commit f007ea26, the order of the %es and %ds segment registers
got accidentally swapped, so synthesized 'struct pt_regs' frames
have the two values inverted. It's almost sure that these values
never matter, and that they also never differ. But wrong is wrong.
Signed-off-by: Roland McGrath <roland@redhat.com>
The fixed bar capability structure is searched in PCI extended
configuration space. We need to make sure there is a valid capability
ID to begin with otherwise, the search code may stuck in a infinite
loop which results in boot hang. This patch adds additional check for
cap ID 0, which is also invalid, and indicates end of chain.
End of chain is supposed to have all fields zero, but that doesn't
seem to always be the case in the field.
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
LKML-Reference: <1279306706-27087-1-git-send-email-jacob.jun.pan@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Found one x2apic system kexec loop test failed
when CONFIG_NMI_WATCHDOG=y (old) or CONFIG_LOCKUP_DETECTOR=y (current tip)
first kernel can kexec second kernel, but second kernel can not kexec third one.
it can be duplicated on another system with BIOS preenabled x2apic.
First kernel can not kexec second kernel.
It turns out, when kernel boot with pre-enabled x2apic, it will not execute
disable_local_APIC on shutdown path.
when init_apic_mappings() is called in setup_arch, it will skip setting of
apic_phys when x2apic_mode is set. ( x2apic_mode is much early check_x2apic())
Then later, disable_local_APIC() will bail out early because !apic_phys.
So check !x2apic_mode in x2apic_mode in disable_local_APIC with !apic_phys.
another solution could be updating init_apic_mappings() to set apic_phys even
for preenabled x2apic system. Actually even for x2apic system, that lapic
address is mapped already in early stage.
BTW: is there any x2apic preenabled system with apicid of boot cpu > 255?
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C3EB22B.3000701@kernel.org>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: stable@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
If we fail to assign resources to a PCI BAR, this patch makes us try the
original address from BIOS rather than leaving it disabled.
Linux tries to make sure all PCI device BARs are inside the upstream
PCI host bridge or P2P bridge apertures, reassigning BARs if necessary.
Windows does similar reassignment.
Before this patch, if we could not move a BAR into an aperture, we left
the resource unassigned, i.e., at address zero. Windows leaves such BARs
at the original BIOS addresses, and this patch makes Linux do the same.
This is a bit ugly because we disable the resource long before we try to
reassign it, so we have to keep track of the BIOS BAR address somewhere.
For lack of a better place, I put it in the struct pci_dev.
I think it would be cleaner to attempt the assignment immediately when the
claim fails, so we could easily remember the original address. But we
currently claim motherboard resources in the middle, after attempting to
claim PCI resources and before assigning new PCI resources, and changing
that is a fairly big job.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16263
Reported-by: Andrew <nitr0@seti.kr.ua>
Tested-by: Andrew <nitr0@seti.kr.ua>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
commit 30a564be (x86, hpet: Restrict read back to affected ATI
chipset) restricted the workaround for the HPET bug to SMX00
chipsets. This was reasonable as those were the only ones against
which we ever got a bug report.
Stephan Wolf reported now that this patch breaks his IXP400 based
machine. Though it's confirmed to work on other IXP400 based systems.
To error out on the safe side, we force the HPET readback workaround
for all ATI SMbus class chipsets.
Reported-by: Stephan Wolf <stephan@letzte-bankreihe.de>
LKML-Reference: <alpine.LFD.2.00.1007142134140.3321@localhost.localdomain>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Stephan Wolf <stephan@letzte-bankreihe.de>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
input: i8042 - add runtime check in x86's i8042_platform_init
Revert "Input: fixup X86_MRST selects"
Revert "Input: do not force selecting i8042 on Moorestown"
x86, mrst: Add i8042_detect API for Moorestwon platform
x86: Add i8042 pre-detection hook to x86_platform_ops
x86, platform: Export x86_platform to modules
After remove a rmap, we should flush all vcpu's tlb
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
It will just return 0 as there is no i8042 controller
Signed-off-by: Feng Tang <feng.tang@intel.com>
LKML-Reference: <1278342202-10973-3-git-send-email-feng.tang@intel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
