When the last CPU in an rdt_domain goes offline, its rdt_domain struct gets
freed. Current pseudo-locking code is unaware of this scenario and tries to
dereference the freed structure in a few places.
Add checks to prevent pseudo-locking code from doing this.
While further work is needed to seamlessly restore resource groups (not
just pseudo-locking) to their configuration when the domain is brought back
online, the immediate issue of invalid pointers is addressed here.
Fixes: f4e80d67a5 ("x86/intel_rdt: Resctrl files reflect pseudo-locked information")
Fixes: 443810fe61 ("x86/intel_rdt: Create debugfs files for pseudo-locking testing")
Fixes: 746e08590b ("x86/intel_rdt: Create character device exposing pseudo-locked region")
Fixes: 33dc3e410a ("x86/intel_rdt: Make CPU information accessible for pseudo-locked regions")
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/231f742dbb7b00a31cc104416860e27dba6b072d.1539384145.git.reinette.chatre@intel.com
When a new resource group is created it is initialized with a default
allocation that considers which portions of cache are currently
available for sharing across all resource groups or which portions of
cache are currently unused.
If a CDP allocation forms part of a resource group that is in exclusive
mode then it should be ensured that no new allocation overlaps with any
resource that shares the underlying hardware. The current initial
allocation does not take this sharing of hardware into account and
a new allocation in a resource that shares the same
hardware would affect the exclusive resource group.
Fix this by considering the allocation of a peer RDT domain - a RDT
domain sharing the same hardware - as part of the test to determine
which portion of cache is in use and available for use.
Fixes: 95f0b77efa ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: tony.luck@intel.com
Cc: jithu.joseph@intel.com
Cc: gavin.hindman@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/b1f7ec08b1695be067de416a4128466d49684317.1538603665.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The CBM overlap test is used to manage the allocations of RDT resources
where overlap is possible between resource groups. When a resource group
is in exclusive mode then there should be no overlap between resource
groups.
The current overlap test only considers overlap between the same
resources, for example, that usage of a RDT_RESOURCE_L2DATA resource
in one resource group does not overlap with usage of a RDT_RESOURCE_L2DATA
resource in another resource group. The problem with this is that it
allows overlap between a RDT_RESOURCE_L2DATA resource in one resource
group with a RDT_RESOURCE_L2CODE resource in another resource group -
even if both resource groups are in exclusive mode. This is a problem
because even though these appear to be different resources they end up
sharing the same underlying hardware and thus does not fulfill the
user's request for exclusive use of hardware resources.
Fix this by including the CDP peer (if there is one) in every CBM
overlap test. This does not impact the overlap between resources
within the same exclusive resource group that is allowed.
Fixes: 49f7b4efa1 ("x86/intel_rdt: Enable setting of exclusive mode")
Reported-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jithu Joseph <jithu.joseph@intel.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/e538b7f56f7ca15963dce2e00ac3be8edb8a68e1.1538603665.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce a utility that, when provided with a RDT resource and an
instance of this RDT resource (a RDT domain), would return pointers to
the RDT resource and RDT domain that share the same hardware. This is
specific to the CDP resources that share the same hardware.
For example, if a pointer to the RDT_RESOURCE_L2DATA resource (struct
rdt_resource) and a pointer to an instance of this resource (struct
rdt_domain) is provided, then it will return a pointer to the
RDT_RESOURCE_L2CODE resource as well as the specific instance that
shares the same hardware as the provided rdt_domain.
This utility is created in support of the "exclusive" resource group
mode where overlap of resource allocation between resource groups need
to be avoided. The overlap test need to consider not just the matching
resources, but also the resources that share the same hardware.
Temporarily mark it as unused in support of patch testing to avoid
compile warnings until it is used.
Fixes: 49f7b4efa1 ("x86/intel_rdt: Enable setting of exclusive mode")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jithu Joseph <jithu.joseph@intel.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/9b4bc4d59ba2e903b6a3eb17e16ef41a8e7b7c3e.1538603665.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While the DOC at the beginning of lib/bitmap.c explicitly states that
"The number of valid bits in a given bitmap does _not_ need to be an
exact multiple of BITS_PER_LONG.", some of the bitmap operations do
indeed access BITS_PER_LONG portions of the provided bitmap no matter
the size of the provided bitmap. For example, if bitmap_intersects()
is provided with an 8 bit bitmap the operation will access
BITS_PER_LONG bits from the provided bitmap. While the operation
ensures that these extra bits do not affect the result, the memory
is still accessed.
The capacity bitmasks (CBMs) are typically stored in u32 since they
can never exceed 32 bits. A few instances exist where a bitmap_*
operation is performed on a CBM by simply pointing the bitmap operation
to the stored u32 value.
The consequence of this pattern is that some bitmap_* operations will
access out-of-bounds memory when interacting with the provided CBM. This
is confirmed with a KASAN test that reports:
BUG: KASAN: stack-out-of-bounds in __bitmap_intersects+0xa2/0x100
and
BUG: KASAN: stack-out-of-bounds in __bitmap_weight+0x58/0x90
Fix this by moving any CBM provided to a bitmap operation needing
BITS_PER_LONG to an 'unsigned long' variable.
[ tglx: Changed related function arguments to unsigned long and got rid
of the _cbm extra step ]
Fixes: 72d5050566 ("x86/intel_rdt: Add utilities to test pseudo-locked region possibility")
Fixes: 49f7b4efa1 ("x86/intel_rdt: Enable setting of exclusive mode")
Fixes: d9b48c86eb ("x86/intel_rdt: Display resource groups' allocations' size in bytes")
Fixes: 95f0b77efa ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/69a428613a53f10e80594679ac726246020ff94f.1538686926.git.reinette.chatre@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In resctrl filesystem, mount options exist to enable L3/L2 CDP and MBA
Software Controller features if the platform supports them:
mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps]] /sys/fs/resctrl
But currently only "cdp" option is displayed in /proc/mounts. "cdpl2" and
"mba_MBps" options are not shown even when they are active.
Before:
# mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl
# grep resctrl /proc/mounts
/sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp 0 0
After:
# mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl
# grep resctrl /proc/mounts
/sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp,mba_MBps 0 0
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1536796118-60135-1-git-send-email-fenghua.yu@intel.com
In order to determine a sane default cache allocation for a new CAT/CDP
resource group, all resource groups are checked to determine which cache
portions are available to share. At this time all possible CLOSIDs
that can be supported by the resource is checked. This is problematic
if the resource supports more CLOSIDs than another CAT/CDP resource. In
this case, the number of CLOSIDs that could be allocated are fewer than
the number of CLOSIDs that can be supported by the resource.
Limit the check of closids to that what is supported by the system based
on the minimum across all resources.
Fixes: 95f0b77ef ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-10-git-send-email-fenghua.yu@intel.com
It is possible for a resource group to consist out of MBA as well as
CAT/CDP resources. The "exclusive" resource mode only applies to the
CAT/CDP resources since MBA allocations cannot be specified to overlap
or not. When a user requests a resource group to become "exclusive" then it
can only be successful if there are CAT/CDP resources in the group
and none of their CBMs associated with the group's CLOSID overlaps with
any other resource group.
Fix the "exclusive" mode setting by failing if there isn't any CAT/CDP
resource in the group and ensuring that the CBM checking is only done on
CAT/CDP resources.
Fixes: 49f7b4efa ("x86/intel_rdt: Enable setting of exclusive mode")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-9-git-send-email-fenghua.yu@intel.com
A loop is used to check if a CAT resource's CBM of one CLOSID
overlaps with the CBM of another CLOSID of the same resource. The loop
is run over all CLOSIDs supported by the resource.
The problem with running the loop over all CLOSIDs supported by the
resource is that its number of supported CLOSIDs may be more than the
number of supported CLOSIDs on the system, which is the minimum number of
CLOSIDs supported across all resources.
Fix the loop to only consider the number of system supported CLOSIDs,
not all that are supported by the resource.
Fixes: 49f7b4efa ("x86/intel_rdt: Enable setting of exclusive mode")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-8-git-send-email-fenghua.yu@intel.com
When a new resource group is created, it is initialized with sane
defaults that currently assume the resource being initialized is a CAT
resource. This code path is also followed by a MBA resource that is not
allocated the same as a CAT resource and as a result we encounter the
following unchecked MSR access error:
unchecked MSR access error: WRMSR to 0xd51 (tried to write 0x0000
000000000064) at rIP: 0xffffffffae059994 (native_write_msr+0x4/0x20)
Call Trace:
mba_wrmsr+0x41/0x80
update_domains+0x125/0x130
rdtgroup_mkdir+0x270/0x500
Fix the above by ensuring the initial allocation is only attempted on a
CAT resource.
Fixes: 95f0b77ef ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-6-git-send-email-fenghua.yu@intel.com
When multiple resources are managed by RDT, the number of CLOSIDs used
is the minimum of the CLOSIDs supported by each resource. In the function
rdt_bit_usage_show(), the annotated bitmask is created to depict how the
CAT supporting caches are being used. During this annotated bitmask
creation, each resource group is queried for its mode that is used as a
label in the annotated bitmask.
The maximum number of resource groups is currently assumed to be the
number of CLOSIDs supported by the resource for which the information is
being displayed. This is incorrect since the number of active CLOSIDs is
the minimum across all resources.
If information for a cache instance with more CLOSIDs than another is
being generated we thus encounter a warning like:
invalid mode for closid 8
WARNING: CPU: 88 PID: 1791 at [SNIP]/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
:827 rdt_bit_usage_show+0x221/0x2b0
Fix this by ensuring that only the number of supported CLOSIDs are
considered.
Fixes: e651901187 ("x86/intel_rdt: Introduce "bit_usage" to display cache allocations details")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-5-git-send-email-fenghua.yu@intel.com
The number of CLOSIDs supported by a system is the minimum number of
CLOSIDs supported by any of its resources. Care should be taken when
iterating over the CLOSIDs of a resource since it may be that the number
of CLOSIDs supported on the system is less than the number of CLOSIDs
supported by the resource.
Introduce a helper function that can be used to query the number of
CLOSIDs that is supported by all resources, irrespective of how many
CLOSIDs are supported by a particular resource.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-4-git-send-email-fenghua.yu@intel.com
Chen Yu reported a divide-by-zero error when accessing the 'size'
resctrl file when a MBA resource is enabled.
divide error: 0000 [#1] SMP PTI
CPU: 93 PID: 1929 Comm: cat Not tainted 4.19.0-rc2-debug-rdt+ #25
RIP: 0010:rdtgroup_cbm_to_size+0x7e/0xa0
Call Trace:
rdtgroup_size_show+0x11a/0x1d0
seq_read+0xd8/0x3b0
Quoting Chen Yu's report: This is because for MB resource, the
r->cache.cbm_len is zero, thus calculating size in rdtgroup_cbm_to_size()
will trigger the exception.
Fix this issue in the 'size' file by getting correct memory bandwidth value
which is in MBps when MBA software controller is enabled or in percentage
when MBA software controller is disabled.
Fixes: d9b48c86eb ("x86/intel_rdt: Display resource groups' allocations in bytes")
Reported-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Link: https://lkml.kernel.org/r/20180904174614.26682-1-yu.c.chen@intel.com
Link: https://lkml.kernel.org/r/1537048707-76280-3-git-send-email-fenghua.yu@intel.com
Pull networking updates from David Miller:
"Highlights:
- Gustavo A. R. Silva keeps working on the implicit switch fallthru
changes.
- Support 802.11ax High-Efficiency wireless in cfg80211 et al, From
Luca Coelho.
- Re-enable ASPM in r8169, from Kai-Heng Feng.
- Add virtual XFRM interfaces, which avoids all of the limitations of
existing IPSEC tunnels. From Steffen Klassert.
- Convert GRO over to use a hash table, so that when we have many
flows active we don't traverse a long list during accumluation.
- Many new self tests for routing, TC, tunnels, etc. Too many
contributors to mention them all, but I'm really happy to keep
seeing this stuff.
- Hardware timestamping support for dpaa_eth/fsl-fman from Yangbo Lu.
- Lots of cleanups and fixes in L2TP code from Guillaume Nault.
- Add IPSEC offload support to netdevsim, from Shannon Nelson.
- Add support for slotting with non-uniform distribution to netem
packet scheduler, from Yousuk Seung.
- Add UDP GSO support to mlx5e, from Boris Pismenny.
- Support offloading of Team LAG in NFP, from John Hurley.
- Allow to configure TX queue selection based upon RX queue, from
Amritha Nambiar.
- Support ethtool ring size configuration in aquantia, from Anton
Mikaev.
- Support DSCP and flowlabel per-transport in SCTP, from Xin Long.
- Support list based batching and stack traversal of SKBs, this is
very exciting work. From Edward Cree.
- Busyloop optimizations in vhost_net, from Toshiaki Makita.
- Introduce the ETF qdisc, which allows time based transmissions. IGB
can offload this in hardware. From Vinicius Costa Gomes.
- Add parameter support to devlink, from Moshe Shemesh.
- Several multiplication and division optimizations for BPF JIT in
nfp driver, from Jiong Wang.
- Lots of prepatory work to make more of the packet scheduler layer
lockless, when possible, from Vlad Buslov.
- Add ACK filter and NAT awareness to sch_cake packet scheduler, from
Toke Høiland-Jørgensen.
- Support regions and region snapshots in devlink, from Alex Vesker.
- Allow to attach XDP programs to both HW and SW at the same time on
a given device, with initial support in nfp. From Jakub Kicinski.
- Add TLS RX offload and support in mlx5, from Ilya Lesokhin.
- Use PHYLIB in r8169 driver, from Heiner Kallweit.
- All sorts of changes to support Spectrum 2 in mlxsw driver, from
Ido Schimmel.
- PTP support in mv88e6xxx DSA driver, from Andrew Lunn.
- Make TCP_USER_TIMEOUT socket option more accurate, from Jon
Maxwell.
- Support for templates in packet scheduler classifier, from Jiri
Pirko.
- IPV6 support in RDS, from Ka-Cheong Poon.
- Native tproxy support in nf_tables, from Máté Eckl.
- Maintain IP fragment queue in an rbtree, but optimize properly for
in-order frags. From Peter Oskolkov.
- Improvde handling of ACKs on hole repairs, from Yuchung Cheng"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1996 commits)
bpf: test: fix spelling mistake "REUSEEPORT" -> "REUSEPORT"
hv/netvsc: Fix NULL dereference at single queue mode fallback
net: filter: mark expected switch fall-through
xen-netfront: fix warn message as irq device name has '/'
cxgb4: Add new T5 PCI device ids 0x50af and 0x50b0
net: dsa: mv88e6xxx: missing unlock on error path
rds: fix building with IPV6=m
inet/connection_sock: prefer _THIS_IP_ to current_text_addr
net: dsa: mv88e6xxx: bitwise vs logical bug
net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd()
ieee802154: hwsim: using right kind of iteration
net: hns3: Add vlan filter setting by ethtool command -K
net: hns3: Set tx ring' tc info when netdev is up
net: hns3: Remove tx ring BD len register in hns3_enet
net: hns3: Fix desc num set to default when setting channel
net: hns3: Fix for phy link issue when using marvell phy driver
net: hns3: Fix for information of phydev lost problem when down/up
net: hns3: Fix for command format parsing error in hclge_is_all_function_id_zero
net: hns3: Add support for serdes loopback selftest
bnxt_en: take coredump_record structure off stack
...
This change allows creating kernfs files and directories with arbitrary
uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending
kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments.
The "simple" kernfs_create_file() and kernfs_create_dir() are left alone
and always create objects belonging to the global root.
When creating symlinks ownership (uid/gid) is taken from the target kernfs
object.
Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a resource group enters pseudo-locksetup mode it reflects that the
platform supports cache pseudo-locking and the resource group is unused,
ready to be used for a pseudo-locked region. Until it is set up as a
pseudo-locked region the resource group is "locked down" such that no new
tasks or cpus can be assigned to it. This is accomplished in a user visible
way by making the cpus, cpus_list, and tasks resctrl files inaccassible
(user cannot read from or write to these files).
When the resource group changes to pseudo-locked mode it represents a cache
pseudo-locked region. While not appropriate to make any changes to the cpus
assigned to this region it is useful to make it easy for the user to see
which cpus are associated with the pseudo-locked region.
Modify the permissions of the cpus/cpus_list file when the resource group
changes to pseudo-locked mode to support reading (not writing). The
information presented to the user when reading the file are the cpus
associated with the pseudo-locked region.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/12756b7963b6abc1bffe8fb560b87b75da827bd1.1530421961.git.reinette.chatre@intel.com
As the mode of a resource group changes, the operations it can support may
also change. One way in which the supported operations are managed is to
modify the permissions of the files within the resource group's resctrl
directory.
At the moment only two possible permissions are supported: the default
permissions or no permissions in support for when the operation is "locked
down". It is possible where an operation on a resource group may have more
possibilities. For example, if by default changes can be made to the
resource group by writing to a resctrl file while the current settings can
be obtained by reading from the file, then it may be possible that in
another mode it is only possible to read the current settings, and not
change them.
Make it possible to modify some of the permissions of a resctrl file in
support of a more flexible way to manage the operations on a resource
group. In this preparation work the original behavior is maintained where
all permissions are restored.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/8773aadfade7bcb2c48a45fa294a04d2c03bb0a1.1530421961.git.reinette.chatre@intel.com
The user can request entering pseudo-locksetup mode by writing
"pseudo-locksetup" to the mode file. Act on this request as well as
support switching from a pseudo-locksetup mode (before pseudo-locked
mode was entered). It is not supported to modify the mode once
pseudo-locked mode has been entered.
The schemata reflects the new mode by adding "uninitialized" to all
resources. The size resctrl file reports zero for all cache domains in
support of the uninitialized nature. Since there are no users of this
class of service its allocations can be ignored when searching for
appropriate default allocations for new resource groups. For the same
reason resource groups in pseudo-locksetup mode are not considered when
testing if new resource groups may overlap.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/56f553334708022903c296284e62db3bbc1ff150.1529706536.git.reinette.chatre@intel.com
When a resource group is used for Cache Pseudo-Locking then the region of
cache ends up being orphaned with no class of service referring to it. The
resctrl files intended to manage how the classes of services are utilized
thus become irrelevant.
The fact that a resctrl file is not relevant can be communicated to the
user by setting all of its permissions to zero. That is, its read, write,
and execute permissions are unset for all users.
Introduce two utilities, rdtgroup_kn_mode_restrict() and
rdtgroup_kn_mode_restore(), that can be used to restrict and restore the
permissions of a file or directory belonging to a resource group.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/7afdbf5551b2f93cd45d61fbf5e01d87331f529a.1529706536.git.reinette.chatre@intel.com
By default, if the opener has CAP_DAC_OVERRIDE, a kernfs file can be opened
regardless of RW permissions. Writing to a kernfs file will thus succeed
even if permissions are 0000.
It's required to restrict the actions that can be performed on a resource
group from userspace based on the mode of the resource group. This
restriction will be done through a modification of the file
permissions. That is, for example, if a resource group is locked then the
user cannot add tasks to the resource group.
For this restriction through file permissions to work it has to be ensured
that the permissions are always respected. To do so the resctrl filesystem
is created with the KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK flag that will result
in open(2) failing with -EACCESS regardless of CAP_DAC_OVERRIDE if the
permission does not have the respective read or write access.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/26f4fc25f110bfc07c2d2c8b2c4ee904922fedf7.1529706536.git.reinette.chatre@intel.com
With cache regions now explicitly marked as "shareable" or "exclusive"
we would like to communicate to the user how portions of the cache
are used.
Introduce "bit_usage" that indicates for each resource
how portions of the cache are configured to be used.
To assist the user to distinguish whether the sharing is from software or
hardware we add the following annotation:
0 - currently unused
X - currently available for sharing and used by software and hardware
H - currently used by hardware only but available for software use
S - currently used and shareable by software only
E - currently used exclusively by one resource group
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/105d44c40e582c2b7e2dccf0ae247e5e61137d4b.1529706536.git.reinette.chatre@intel.com
Currently when a new resource group is created its allocations would be
those that belonged to the resource group to which its closid belonged
previously.
That is, we can encounter a case like:
mkdir newgroup
cat newgroup/schemata
L2:0=ff;1=ff
echo 'L2:0=0xf0;1=0xf0' > newgroup/schemata
cat newgroup/schemata
L2:0=0xf0;1=0xf0
rmdir newgroup
mkdir newnewgroup
cat newnewgroup/schemata
L2:0=0xf0;1=0xf0
When the new group is created it would be reasonable to expect its
allocations to be initialized with all regions that it can possibly use.
At this time these regions would be all that are shareable by other
resource groups as well as regions that are not currently used.
If the available cache region is found to be non-contiguous the
available region is adjusted to enforce validity.
When a new resource group is created the hardware is initialized with
these new default allocations.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/c468ed79340b63024111978e01430bb9589d85c0.1529706536.git.reinette.chatre@intel.com
When MBA software controller is enabled, a per domain storage is required
for user specified bandwidth in "MBps" and the "percentage" values which
are programmed into the IA32_MBA_THRTL_MSR. Add support for these data
structures and initialization.
The MBA percentage values have a default max value of 100 but however the
max value in MBps is not available from the hardware so it's set to
U32_MAX.
This simply says that the control group can use all bandwidth by default
but does not say what is the actual max bandwidth available. The actual
bandwidth that is available may depend on lot of factors like QPI link,
number of memory channels, memory channel frequency, its width and memory
speed, how many channels are configured and also if memory interleaving is
enabled. So there is no way to determine the maximum at runtime reliably.
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/1524263781-14267-4-git-send-email-vikas.shivappa@linux.intel.com
If no monitoring feature is detected because all monitoring features are
disabled during boot time or there is no monitoring feature in hardware,
creating rdtgroup sub-directory by "mkdir" command reports error:
mkdir: cannot create directory ‘/sys/fs/resctrl/p1’: No such file or directory
But the sub-directory actually is generated and content is correct:
cpus cpus_list schemata tasks
The error is because rdtgroup_mkdir_ctrl_mon() returns non zero value after
the sub-directory is created and the returned value is reported as an error
to user.
Clear the returned value to report to user that the sub-directory is
actually created successfully.
Signed-off-by: Wang Hui <john.wanghui@huawei.com>
Signed-off-by: Zhang Yanfei <yanfei.zhang@huawei.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V Shankar <ravi.v.shankar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vikas <vikas.shivappa@intel.com>
Cc: Xiaochen Shen <xiaochen.shen@intel.com>
Link: http://lkml.kernel.org/r/1519356363-133085-1-git-send-email-fenghua.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Bit 0 in MSR IA32_L2_QOS_CFG (0xc82) is L2 CDP enable bit. By default,
the bit is zero, i.e. L2 CAT is enabled, and L2 CDP is disabled. When
the resctrl mount parameter "cdpl2" is given, the bit is set to 1 and L2
CDP is enabled.
In L2 CDP mode, the L2 CAT mask MSRs are re-mapped into interleaved pairs
of mask MSRs for code (referenced by an odd CLOSID) and data (referenced by
an even CLOSID).
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: Vikas" <vikas.shivappa@intel.com>
Cc: Sai Praneeth" <sai.praneeth.prakhya@intel.com>
Cc: Reinette" <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/1513810644-78015-6-git-send-email-fenghua.yu@intel.com
The assignment to the 'files' variable is immediately overwritten
in the following line. Remove the older assignment, which was meant
specifially for creating control groups files.
Fixes: c7d9aac613 ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: tony.luck@intel.com
Cc: vikas.shivappa@intel.com
Link: https://lkml.kernel.org/r/1507157337-18118-1-git-send-email-jithu.joseph@intel.com
Mostly this is about running out of RMIDs or CLOSIDs. Other
errors are various internal errors.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/027cf1ffb3a3695f2d54525813a1d644887353cf.1506382469.git.tony.luck@intel.com
Can't add a cpu to a monitor group unless it belongs to parent
group. Can't delete cpus from the default group.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/757a869a25e9fc1b7a2e9bc43e1159455c1964a0.1506382469.git.tony.luck@intel.com
