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mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-04 20:19:47 +08:00
Commit Graph

271 Commits

Author SHA1 Message Date
Linus Torvalds
48795f90cb - Remove the less generic CPU matching infra around struct x86_cpu_desc and
use the generic struct x86_cpu_id thing
 
 - Remove magic naked numbers for CPUID functions and use proper defines of the
   prefix CPUID_LEAF_*. Consolidate some of the crazy use around the tree
 
 - Smaller cleanups and improvements
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Merge tag 'x86_cpu_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpuid updates from Borislav Petkov:

 - Remove the less generic CPU matching infra around struct x86_cpu_desc
   and use the generic struct x86_cpu_id thing

 - Remove magic naked numbers for CPUID functions and use proper defines
   of the prefix CPUID_LEAF_*. Consolidate some of the crazy use around
   the tree

 - Smaller cleanups and improvements

* tag 'x86_cpu_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Make all all CPUID leaf names consistent
  x86/fpu: Remove unnecessary CPUID level check
  x86/fpu: Move CPUID leaf definitions to common code
  x86/tsc: Remove CPUID "frequency" leaf magic numbers.
  x86/tsc: Move away from TSC leaf magic numbers
  x86/cpu: Move TSC CPUID leaf definition
  x86/cpu: Refresh DCA leaf reading code
  x86/cpu: Remove unnecessary MwAIT leaf checks
  x86/cpu: Use MWAIT leaf definition
  x86/cpu: Move MWAIT leaf definition to common header
  x86/cpu: Remove 'x86_cpu_desc' infrastructure
  x86/cpu: Move AMD erratum 1386 table over to 'x86_cpu_id'
  x86/cpu: Replace PEBS use of 'x86_cpu_desc' use with 'x86_cpu_id'
  x86/cpu: Expose only stepping min/max interface
  x86/cpu: Introduce new microcode matching helper
  x86/cpufeature: Document cpu_feature_enabled() as the default to use
  x86/paravirt: Remove the WBINVD callback
  x86/cpufeatures: Free up unused feature bits
2025-01-21 09:30:59 -08:00
Sohil Mehta
7a470e826d x86/cpufeatures: Free up unused feature bits
Linux defined feature bits X86_FEATURE_P3 and X86_FEATURE_P4 are not
used anywhere. Commit f31d731e44 ("x86: use X86_FEATURE_NOPL in
alternatives") got rid of the last usage in 2008. Remove the related
mappings and code.

Just like all X86_FEATURE bits, the raw bit numbers can be exposed to
userspace via MODULE_DEVICE_TABLE(). There is a very small theoretical
chance of userspace getting confused if these bits got reassigned and
changed logical meaning.  But these bits were never used for a device
table, so it's highly unlikely this will ever happen in practice.

[ dhansen: clarify userspace visibility of these bits ]

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/all/20241107233000.2742619-1-sohil.mehta%40intel.com
2024-12-06 10:57:44 +01:00
Len Brown
c9a4b55431 x86/cpu: Add Lunar Lake to list of CPUs with a broken MONITOR implementation
Under some conditions, MONITOR wakeups on Lunar Lake processors
can be lost, resulting in significant user-visible delays.

Add Lunar Lake to X86_BUG_MONITOR so that wake_up_idle_cpu()
always sends an IPI, avoiding this potential delay.

Reported originally here:

	https://bugzilla.kernel.org/show_bug.cgi?id=219364

[ dhansen: tweak subject ]

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown%40intel.com
2024-12-04 12:30:14 -08:00
Linus Torvalds
0892d74213 x86/splitlock changes for v6.13:
- Move Split and Bus lock code to a dedicated file (Ravi Bangoria)
  - Add split/bus lock support for AMD (Ravi Bangoria)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-splitlock-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 splitlock updates from Ingo Molnar:

 - Move Split and Bus lock code to a dedicated file (Ravi Bangoria)

 - Add split/bus lock support for AMD (Ravi Bangoria)

* tag 'x86-splitlock-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bus_lock: Add support for AMD
  x86/split_lock: Move Split and Bus lock code to a dedicated file
2024-11-19 14:34:02 -08:00
Dapeng Mi
2eb2802a41 x86/cpu/intel: Define helper to get CPU core native ID
Define helper get_this_hybrid_cpu_native_id() to return the CPU core
native ID. This core native ID combining with core type can be used to
figure out the CPU core uarch uniquely.

Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lkml.kernel.org/r/20240820073853.1974746-3-dapeng1.mi@linux.intel.com
2024-10-07 09:28:43 +02:00
Dave Hansen
fd82221a59 x86/cpu/intel: Replace PAT erratum model/family magic numbers with symbolic IFM references
There's an erratum that prevents the PAT from working correctly:

   https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/pentium-dual-core-specification-update.pdf
   # Document 316515 Version 010

The kernel currently disables PAT support on those CPUs, but it
does it with some magic numbers.

Replace the magic numbers with the new "IFM" macros.

Make the check refer to the last affected CPU (INTEL_CORE_YONAH)
rather than the first fixed one. This makes it easier to find the
documentation of the erratum since Intel documents where it is
broken and not where it is fixed.

I don't think the Pentium Pro (or Pentium II) is actually affected.
But the old check included them, so it can't hurt to keep doing the
same.  I'm also not completely sure about the "Pentium M" CPUs
(models 0x9 and 0xd).  But, again, they were included in in the
old checks and were close Pentium III derivatives, so are likely
affected.

While we're at it, revise the comment referring to the erratum name
and making sure it is a quote of the language from the actual errata
doc.  That should make it easier to find in the future when the URL
inevitably changes.

Why bother with this in the first place? It actually gets rid of one
of the very few remaining direct references to c->x86{,_model}.

No change in functionality intended.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Link: https://lore.kernel.org/r/20240829220042.1007820-1-dave.hansen@linux.intel.com
2024-09-03 11:18:58 +02:00
Ravi Bangoria
408eb7417a x86/bus_lock: Add support for AMD
Add Bus Lock Detect (called Bus Lock Trap in AMD docs) support for AMD
platforms. Bus Lock Detect is enumerated with CPUID Fn0000_0007_ECX_x0
bit [24 / BUSLOCKTRAP]. It can be enabled through MSR_IA32_DEBUGCTLMSR.
When enabled, hardware clears DR6[11] and raises a #DB exception on
occurrence of Bus Lock if CPL > 0. More detail about the feature can be
found in AMD APM[1].

[1]: AMD64 Architecture Programmer's Manual Pub. 40332, Rev. 4.07 - June
     2023, Vol 2, 13.1.3.6 Bus Lock Trap
     https://bugzilla.kernel.org/attachment.cgi?id=304653

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/all/20240808062937.1149-3-ravi.bangoria@amd.com
2024-08-08 18:02:15 +02:00
Ravi Bangoria
350afa8a11 x86/split_lock: Move Split and Bus lock code to a dedicated file
Bus Lock Detect functionality on AMD platforms works identical to Intel.

Move split_lock and bus_lock specific code from intel.c to a dedicated
file so that it can be compiled and supported on non-Intel platforms.

Also, introduce CONFIG_X86_BUS_LOCK_DETECT, make it dependent on
CONFIG_CPU_SUP_INTEL and add compilation dependency of the new bus_lock.c
file on CONFIG_X86_BUS_LOCK_DETECT.

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/all/20240808062937.1149-2-ravi.bangoria@amd.com
2024-08-08 18:02:15 +02:00
Linus Torvalds
d679783188 - Flip the logic to add feature names to /proc/cpuinfo to having to
explicitly specify the flag if there's a valid reason to show it in
   /proc/cpuinfo
 
 - Switch a bunch of Intel x86 model checking code to the new CPU model
   defines
 
 - Fixes and cleanups
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Merge tag 'x86_cpu_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu model updates from Borislav Petkov:

 - Flip the logic to add feature names to /proc/cpuinfo to having to
   explicitly specify the flag if there's a valid reason to show it in
   /proc/cpuinfo

 - Switch a bunch of Intel x86 model checking code to the new CPU model
   defines

 - Fixes and cleanups

* tag 'x86_cpu_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/intel: Drop stray FAM6 check with new Intel CPU model defines
  x86/cpufeatures: Flip the /proc/cpuinfo appearance logic
  x86/CPU/AMD: Always inline amd_clear_divider()
  x86/mce/inject: Add missing MODULE_DESCRIPTION() line
  perf/x86/rapl: Switch to new Intel CPU model defines
  x86/boot: Switch to new Intel CPU model defines
  x86/cpu: Switch to new Intel CPU model defines
  perf/x86/intel: Switch to new Intel CPU model defines
  x86/virt/tdx: Switch to new Intel CPU model defines
  x86/PCI: Switch to new Intel CPU model defines
  x86/cpu/intel: Switch to new Intel CPU model defines
  x86/platform/intel-mid: Switch to new Intel CPU model defines
  x86/pconfig: Remove unused MKTME pconfig code
  x86/cpu: Remove useless work in detect_tme_early()
2024-07-15 20:25:16 -07:00
Andrew Cooper
34b3fc558b x86/cpu/intel: Drop stray FAM6 check with new Intel CPU model defines
The outer if () should have been dropped when switching to c->x86_vfm.

Fixes: 6568fc18c2 ("x86/cpu/intel: Switch to new Intel CPU model defines")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20240529183605.17520-1-andrew.cooper3@citrix.com
2024-06-29 16:10:37 +02:00
Thomas Gleixner
0c2f6d0461 x86/topology/intel: Unlock CPUID before evaluating anything
Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If
this bit is set by the BIOS then CPUID evaluation including topology
enumeration does not work correctly as the evaluation code does not try
to analyze any leaf greater than two.

This went unnoticed before because the original topology code just
repeated evaluation several times and managed to overwrite the initial
limited information with the correct one later. The new evaluation code
does it once and therefore ends up with the limited and wrong
information.

Cure this by unlocking CPUID right before evaluating anything which
depends on the maximum CPUID leaf being greater than two instead of
rereading stuff after unlock.

Fixes: 22d63660c3 ("x86/cpu: Use common topology code for Intel")
Reported-by: Peter Schneider <pschneider1968@googlemail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Peter Schneider <pschneider1968@googlemail.com>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/fd3f73dc-a86f-4bcf-9c60-43556a21eb42@googlemail.com
2024-05-31 20:25:56 +02:00
Tony Luck
6568fc18c2 x86/cpu/intel: Switch to new Intel CPU model defines
New CPU #defines encode vendor and family as well as model.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20240520224620.9480-29-tony.luck%40intel.com
2024-05-28 10:59:02 -07:00
Alison Schofield
98b83cf0c1 x86/cpu: Remove useless work in detect_tme_early()
TME (Total Memory Encryption) and MKTME (Multi-Key Total Memory
Encryption) BIOS detection were introduced together here [1] and
are loosely coupled in the Intel CPU init code.

TME is a hardware only feature and its BIOS status is all that needs
to be shared with the kernel user: enabled or disabled. The TME
algorithm the BIOS is using and whether or not the kernel recognizes
that algorithm is useless to the kernel user.

MKTME is a hardware feature that requires kernel support. MKTME
detection code was added in advance of broader kernel support for
MKTME that never followed. So, rather than continuing to spew
needless and confusing messages about BIOS MKTME status, remove
most of the MKTME pieces from detect_tme_early().

Keep one useful message: alert the user when BIOS enabled MKTME
reduces the available physical address bits. Recovery of the MKTME
consumed bits requires a reboot with MKTME disabled in BIOS.

There is no functional change for the user, only a change in boot
messages. Below is one example when both TME and MKTME are enabled
in BIOS with AES_XTS_256 which is unknown to the detect tme code.

Before:
[] x86/tme: enabled by BIOS
[] x86/tme: Unknown policy is active: 0x2
[] x86/mktme: No known encryption algorithm is supported: 0x4
[] x86/mktme: enabled by BIOS
[] x86/mktme: 127 KeyIDs available

After:
[] x86/tme: enabled by BIOS
[] x86/mktme: BIOS enable: x86_phys_bits reduced by 8

[1]
commit cb06d8e3d0 ("x86/tme: Detect if TME and MKTME is activated by BIOS")

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/86dfdf6ced8c9b790f9376bf6c7e22b5608f47c2.1715054189.git.alison.schofield%40intel.com
2024-05-28 08:45:17 -07:00
Bingsong Si
cd2236c2f4 x86/cpu: Clear TME feature flag if TME is not enabled by BIOS
When TME is disabled by BIOS, the dmesg output is:

  x86/tme: not enabled by BIOS

... and TME functionality is not enabled by the kernel, but the TME feature
is still shown in /proc/cpuinfo.

Clear it.

[ mingo: Clarified changelog ]

Signed-off-by: Bingsong Si <sibs@chinatelecom.cn>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "Huang, Kai" <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20240311071938.13247-1-sibs@chinatelecom.cn
2024-03-26 09:49:32 +01:00
Ingo Molnar
9b9c280b9a Merge branch 'x86/urgent' into x86/apic, to resolve conflicts
Conflicts:
	arch/x86/kernel/cpu/common.c
	arch/x86/kernel/cpu/intel.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-02-27 10:09:49 +01:00
Paolo Bonzini
6890cb1ace x86/cpu/intel: Detect TME keyid bits before setting MTRR mask registers
MKTME repurposes the high bit of physical address to key id for encryption
key and, even though MAXPHYADDR in CPUID[0x80000008] remains the same,
the valid bits in the MTRR mask register are based on the reduced number
of physical address bits.

detect_tme() in arch/x86/kernel/cpu/intel.c detects TME and subtracts
it from the total usable physical bits, but it is called too late.
Move the call to early_init_intel() so that it is called in setup_arch(),
before MTRRs are setup.

This fixes boot on TDX-enabled systems, which until now only worked with
"disable_mtrr_cleanup".  Without the patch, the values written to the
MTRRs mask registers were 52-bit wide (e.g. 0x000fffff_80000800) and
the writes failed; with the patch, the values are 46-bit wide, which
matches the reduced MAXPHYADDR that is shown in /proc/cpuinfo.

Reported-by: Zixi Chen <zixchen@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240131230902.1867092-3-pbonzini%40redhat.com
2024-02-26 08:16:16 -08:00
Thomas Gleixner
22d63660c3 x86/cpu: Use common topology code for Intel
Intel CPUs use either topology leaf 0xb/0x1f evaluation or the legacy
SMP/HT evaluation based on CPUID leaf 0x1/0x4.

Move it over to the consolidated topology code and remove the random
topology hacks which are sprinkled into the Intel and the common code.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153624.893644349@linutronix.de
2024-02-15 22:07:37 +01:00
Linus Torvalds
426ee5196d sysctl-6.7-rc1
To help make the move of sysctls out of kernel/sysctl.c not incur a size
 penalty sysctl has been changed to allow us to not require the sentinel, the
 final empty element on the sysctl array. Joel Granados has been doing all this
 work. On the v6.6 kernel we got the major infrastructure changes required to
 support this. For v6.7-rc1 we have all arch/ and drivers/ modified to remove
 the sentinel. Both arch and driver changes have been on linux-next for a bit
 less than a month. It is worth re-iterating the value:
 
   - this helps reduce the overall build time size of the kernel and run time
      memory consumed by the kernel by about ~64 bytes per array
   - the extra 64-byte penalty is no longer inncurred now when we move sysctls
     out from kernel/sysctl.c to their own files
 
 For v6.8-rc1 expect removal of all the sentinels and also then the unneeded
 check for procname == NULL.
 
 The last 2 patches are fixes recently merged by Krister Johansen which allow
 us again to use softlockup_panic early on boot. This used to work but the
 alias work broke it. This is useful for folks who want to detect softlockups
 super early rather than wait and spend money on cloud solutions with nothing
 but an eventual hung kernel. Although this hadn't gone through linux-next it's
 also a stable fix, so we might as well roll through the fixes now.
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Merge tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "To help make the move of sysctls out of kernel/sysctl.c not incur a
  size penalty sysctl has been changed to allow us to not require the
  sentinel, the final empty element on the sysctl array. Joel Granados
  has been doing all this work. On the v6.6 kernel we got the major
  infrastructure changes required to support this. For v6.7-rc1 we have
  all arch/ and drivers/ modified to remove the sentinel. Both arch and
  driver changes have been on linux-next for a bit less than a month. It
  is worth re-iterating the value:

   - this helps reduce the overall build time size of the kernel and run
     time memory consumed by the kernel by about ~64 bytes per array

   - the extra 64-byte penalty is no longer inncurred now when we move
     sysctls out from kernel/sysctl.c to their own files

  For v6.8-rc1 expect removal of all the sentinels and also then the
  unneeded check for procname == NULL.

  The last two patches are fixes recently merged by Krister Johansen
  which allow us again to use softlockup_panic early on boot. This used
  to work but the alias work broke it. This is useful for folks who want
  to detect softlockups super early rather than wait and spend money on
  cloud solutions with nothing but an eventual hung kernel. Although
  this hadn't gone through linux-next it's also a stable fix, so we
  might as well roll through the fixes now"

* tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (23 commits)
  watchdog: move softlockup_panic back to early_param
  proc: sysctl: prevent aliased sysctls from getting passed to init
  intel drm: Remove now superfluous sentinel element from ctl_table array
  Drivers: hv: Remove now superfluous sentinel element from ctl_table array
  raid: Remove now superfluous sentinel element from ctl_table array
  fw loader: Remove the now superfluous sentinel element from ctl_table array
  sgi-xp: Remove the now superfluous sentinel element from ctl_table array
  vrf: Remove the now superfluous sentinel element from ctl_table array
  char-misc: Remove the now superfluous sentinel element from ctl_table array
  infiniband: Remove the now superfluous sentinel element from ctl_table array
  macintosh: Remove the now superfluous sentinel element from ctl_table array
  parport: Remove the now superfluous sentinel element from ctl_table array
  scsi: Remove now superfluous sentinel element from ctl_table array
  tty: Remove now superfluous sentinel element from ctl_table array
  xen: Remove now superfluous sentinel element from ctl_table array
  hpet: Remove now superfluous sentinel element from ctl_table array
  c-sky: Remove now superfluous sentinel element from ctl_talbe array
  powerpc: Remove now superfluous sentinel element from ctl_table arrays
  riscv: Remove now superfluous sentinel element from ctl_table array
  x86/vdso: Remove now superfluous sentinel element from ctl_table array
  ...
2023-11-01 20:51:41 -10:00
Joel Granados
83e291d3f5 arch/x86: Remove now superfluous sentinel elem from ctl_table arrays
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove sentinel element from sld_sysctl and itmt_kern_table. This
removal is safe because register_sysctl_init and register_sysctl
implicitly use the array size in addition to checking for the sentinel.

Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> # for x86
Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-10-10 15:22:02 -07:00
Thomas Gleixner
594957d723 x86/cpu: Remove pointless evaluation of x86_coreid_bits
cpuinfo_x86::x86_coreid_bits is only used by the AMD numa topology code. No
point in evaluating it on non AMD systems.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085112.687588373@linutronix.de
2023-10-10 14:38:18 +02:00
Ashok Raj
82ad097b02 x86/microcode: Include vendor headers into microcode.h
Currently vendor specific headers are included explicitly when used in
common code. Instead, include the vendor specific headers in
microcode.h, and include that in all usages.

No functional change.

Suggested-by: Boris Petkov <bp@alien8.de>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230812195727.776541545@linutronix.de
2023-08-13 18:42:55 +02:00
Thomas Gleixner
4da2131fac x86/microcode/intel: Move microcode functions out of cpu/intel.c
There is really no point to have that in the CPUID evaluation code. Move it
into the Intel-specific microcode handling along with the data
structures, defines and helpers required by it. The exports need to stay
for IFS.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230812195727.719202319@linutronix.de
2023-08-13 18:42:48 +02:00
Linus Torvalds
b6a7828502 modules-6.4-rc1
The summary of the changes for this pull requests is:
 
  * Song Liu's new struct module_memory replacement
  * Nick Alcock's MODULE_LICENSE() removal for non-modules
  * My cleanups and enhancements to reduce the areas where we vmalloc
    module memory for duplicates, and the respective debug code which
    proves the remaining vmalloc pressure comes from userspace.
 
 Most of the changes have been in linux-next for quite some time except
 the minor fixes I made to check if a module was already loaded
 prior to allocating the final module memory with vmalloc and the
 respective debug code it introduces to help clarify the issue. Although
 the functional change is small it is rather safe as it can only *help*
 reduce vmalloc space for duplicates and is confirmed to fix a bootup
 issue with over 400 CPUs with KASAN enabled. I don't expect stable
 kernels to pick up that fix as the cleanups would have also had to have
 been picked up. Folks on larger CPU systems with modules will want to
 just upgrade if vmalloc space has been an issue on bootup.
 
 Given the size of this request, here's some more elaborate details
 on this pull request.
 
 The functional change change in this pull request is the very first
 patch from Song Liu which replaces the struct module_layout with a new
 struct module memory. The old data structure tried to put together all
 types of supported module memory types in one data structure, the new
 one abstracts the differences in memory types in a module to allow each
 one to provide their own set of details. This paves the way in the
 future so we can deal with them in a cleaner way. If you look at changes
 they also provide a nice cleanup of how we handle these different memory
 areas in a module. This change has been in linux-next since before the
 merge window opened for v6.3 so to provide more than a full kernel cycle
 of testing. It's a good thing as quite a bit of fixes have been found
 for it.
 
 Jason Baron then made dynamic debug a first class citizen module user by
 using module notifier callbacks to allocate / remove module specific
 dynamic debug information.
 
 Nick Alcock has done quite a bit of work cross-tree to remove module
 license tags from things which cannot possibly be module at my request
 so to:
 
   a) help him with his longer term tooling goals which require a
      deterministic evaluation if a piece a symbol code could ever be
      part of a module or not. But quite recently it is has been made
      clear that tooling is not the only one that would benefit.
      Disambiguating symbols also helps efforts such as live patching,
      kprobes and BPF, but for other reasons and R&D on this area
      is active with no clear solution in sight.
 
   b) help us inch closer to the now generally accepted long term goal
      of automating all the MODULE_LICENSE() tags from SPDX license tags
 
 In so far as a) is concerned, although module license tags are a no-op
 for non-modules, tools which would want create a mapping of possible
 modules can only rely on the module license tag after the commit
 8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin
 or tristate.conf").  Nick has been working on this *for years* and
 AFAICT I was the only one to suggest two alternatives to this approach
 for tooling. The complexity in one of my suggested approaches lies in
 that we'd need a possible-obj-m and a could-be-module which would check
 if the object being built is part of any kconfig build which could ever
 lead to it being part of a module, and if so define a new define
 -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've
 suggested would be to have a tristate in kconfig imply the same new
 -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names
 mapping to modules always, and I don't think that's the case today. I am
 not aware of Nick or anyone exploring either of these options. Quite
 recently Josh Poimboeuf has pointed out that live patching, kprobes and
 BPF would benefit from resolving some part of the disambiguation as
 well but for other reasons. The function granularity KASLR (fgkaslr)
 patches were mentioned but Joe Lawrence has clarified this effort has
 been dropped with no clear solution in sight [1].
 
 In the meantime removing module license tags from code which could never
 be modules is welcomed for both objectives mentioned above. Some
 developers have also welcomed these changes as it has helped clarify
 when a module was never possible and they forgot to clean this up,
 and so you'll see quite a bit of Nick's patches in other pull
 requests for this merge window. I just picked up the stragglers after
 rc3. LWN has good coverage on the motivation behind this work [2] and
 the typical cross-tree issues he ran into along the way. The only
 concrete blocker issue he ran into was that we should not remove the
 MODULE_LICENSE() tags from files which have no SPDX tags yet, even if
 they can never be modules. Nick ended up giving up on his efforts due
 to having to do this vetting and backlash he ran into from folks who
 really did *not understand* the core of the issue nor were providing
 any alternative / guidance. I've gone through his changes and dropped
 the patches which dropped the module license tags where an SPDX
 license tag was missing, it only consisted of 11 drivers.  To see
 if a pull request deals with a file which lacks SPDX tags you
 can just use:
 
   ./scripts/spdxcheck.py -f \
 	$(git diff --name-only commid-id | xargs echo)
 
 You'll see a core module file in this pull request for the above,
 but that's not related to his changes. WE just need to add the SPDX
 license tag for the kernel/module/kmod.c file in the future but
 it demonstrates the effectiveness of the script.
 
 Most of Nick's changes were spread out through different trees,
 and I just picked up the slack after rc3 for the last kernel was out.
 Those changes have been in linux-next for over two weeks.
 
 The cleanups, debug code I added and final fix I added for modules
 were motivated by David Hildenbrand's report of boot failing on
 a systems with over 400 CPUs when KASAN was enabled due to running
 out of virtual memory space. Although the functional change only
 consists of 3 lines in the patch "module: avoid allocation if module is
 already present and ready", proving that this was the best we can
 do on the modules side took quite a bit of effort and new debug code.
 
 The initial cleanups I did on the modules side of things has been
 in linux-next since around rc3 of the last kernel, the actual final
 fix for and debug code however have only been in linux-next for about a
 week or so but I think it is worth getting that code in for this merge
 window as it does help fix / prove / evaluate the issues reported
 with larger number of CPUs. Userspace is not yet fixed as it is taking
 a bit of time for folks to understand the crux of the issue and find a
 proper resolution. Worst come to worst, I have a kludge-of-concept [3]
 of how to make kernel_read*() calls for modules unique / converge them,
 but I'm currently inclined to just see if userspace can fix this
 instead.
 
 [0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/
 [1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com
 [2] https://lwn.net/Articles/927569/
 [3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org
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Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull module updates from Luis Chamberlain:
 "The summary of the changes for this pull requests is:

   - Song Liu's new struct module_memory replacement

   - Nick Alcock's MODULE_LICENSE() removal for non-modules

   - My cleanups and enhancements to reduce the areas where we vmalloc
     module memory for duplicates, and the respective debug code which
     proves the remaining vmalloc pressure comes from userspace.

  Most of the changes have been in linux-next for quite some time except
  the minor fixes I made to check if a module was already loaded prior
  to allocating the final module memory with vmalloc and the respective
  debug code it introduces to help clarify the issue. Although the
  functional change is small it is rather safe as it can only *help*
  reduce vmalloc space for duplicates and is confirmed to fix a bootup
  issue with over 400 CPUs with KASAN enabled. I don't expect stable
  kernels to pick up that fix as the cleanups would have also had to
  have been picked up. Folks on larger CPU systems with modules will
  want to just upgrade if vmalloc space has been an issue on bootup.

  Given the size of this request, here's some more elaborate details:

  The functional change change in this pull request is the very first
  patch from Song Liu which replaces the 'struct module_layout' with a
  new 'struct module_memory'. The old data structure tried to put
  together all types of supported module memory types in one data
  structure, the new one abstracts the differences in memory types in a
  module to allow each one to provide their own set of details. This
  paves the way in the future so we can deal with them in a cleaner way.
  If you look at changes they also provide a nice cleanup of how we
  handle these different memory areas in a module. This change has been
  in linux-next since before the merge window opened for v6.3 so to
  provide more than a full kernel cycle of testing. It's a good thing as
  quite a bit of fixes have been found for it.

  Jason Baron then made dynamic debug a first class citizen module user
  by using module notifier callbacks to allocate / remove module
  specific dynamic debug information.

  Nick Alcock has done quite a bit of work cross-tree to remove module
  license tags from things which cannot possibly be module at my request
  so to:

   a) help him with his longer term tooling goals which require a
      deterministic evaluation if a piece a symbol code could ever be
      part of a module or not. But quite recently it is has been made
      clear that tooling is not the only one that would benefit.
      Disambiguating symbols also helps efforts such as live patching,
      kprobes and BPF, but for other reasons and R&D on this area is
      active with no clear solution in sight.

   b) help us inch closer to the now generally accepted long term goal
      of automating all the MODULE_LICENSE() tags from SPDX license tags

  In so far as a) is concerned, although module license tags are a no-op
  for non-modules, tools which would want create a mapping of possible
  modules can only rely on the module license tag after the commit
  8b41fc4454 ("kbuild: create modules.builtin without
  Makefile.modbuiltin or tristate.conf").

  Nick has been working on this *for years* and AFAICT I was the only
  one to suggest two alternatives to this approach for tooling. The
  complexity in one of my suggested approaches lies in that we'd need a
  possible-obj-m and a could-be-module which would check if the object
  being built is part of any kconfig build which could ever lead to it
  being part of a module, and if so define a new define
  -DPOSSIBLE_MODULE [0].

  A more obvious yet theoretical approach I've suggested would be to
  have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
  well but that means getting kconfig symbol names mapping to modules
  always, and I don't think that's the case today. I am not aware of
  Nick or anyone exploring either of these options. Quite recently Josh
  Poimboeuf has pointed out that live patching, kprobes and BPF would
  benefit from resolving some part of the disambiguation as well but for
  other reasons. The function granularity KASLR (fgkaslr) patches were
  mentioned but Joe Lawrence has clarified this effort has been dropped
  with no clear solution in sight [1].

  In the meantime removing module license tags from code which could
  never be modules is welcomed for both objectives mentioned above. Some
  developers have also welcomed these changes as it has helped clarify
  when a module was never possible and they forgot to clean this up, and
  so you'll see quite a bit of Nick's patches in other pull requests for
  this merge window. I just picked up the stragglers after rc3. LWN has
  good coverage on the motivation behind this work [2] and the typical
  cross-tree issues he ran into along the way. The only concrete blocker
  issue he ran into was that we should not remove the MODULE_LICENSE()
  tags from files which have no SPDX tags yet, even if they can never be
  modules. Nick ended up giving up on his efforts due to having to do
  this vetting and backlash he ran into from folks who really did *not
  understand* the core of the issue nor were providing any alternative /
  guidance. I've gone through his changes and dropped the patches which
  dropped the module license tags where an SPDX license tag was missing,
  it only consisted of 11 drivers. To see if a pull request deals with a
  file which lacks SPDX tags you can just use:

    ./scripts/spdxcheck.py -f \
	$(git diff --name-only commid-id | xargs echo)

  You'll see a core module file in this pull request for the above, but
  that's not related to his changes. WE just need to add the SPDX
  license tag for the kernel/module/kmod.c file in the future but it
  demonstrates the effectiveness of the script.

  Most of Nick's changes were spread out through different trees, and I
  just picked up the slack after rc3 for the last kernel was out. Those
  changes have been in linux-next for over two weeks.

  The cleanups, debug code I added and final fix I added for modules
  were motivated by David Hildenbrand's report of boot failing on a
  systems with over 400 CPUs when KASAN was enabled due to running out
  of virtual memory space. Although the functional change only consists
  of 3 lines in the patch "module: avoid allocation if module is already
  present and ready", proving that this was the best we can do on the
  modules side took quite a bit of effort and new debug code.

  The initial cleanups I did on the modules side of things has been in
  linux-next since around rc3 of the last kernel, the actual final fix
  for and debug code however have only been in linux-next for about a
  week or so but I think it is worth getting that code in for this merge
  window as it does help fix / prove / evaluate the issues reported with
  larger number of CPUs. Userspace is not yet fixed as it is taking a
  bit of time for folks to understand the crux of the issue and find a
  proper resolution. Worst come to worst, I have a kludge-of-concept [3]
  of how to make kernel_read*() calls for modules unique / converge
  them, but I'm currently inclined to just see if userspace can fix this
  instead"

Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]

* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
  module: add debugging auto-load duplicate module support
  module: stats: fix invalid_mod_bytes typo
  module: remove use of uninitialized variable len
  module: fix building stats for 32-bit targets
  module: stats: include uapi/linux/module.h
  module: avoid allocation if module is already present and ready
  module: add debug stats to help identify memory pressure
  module: extract patient module check into helper
  modules/kmod: replace implementation with a semaphore
  Change DEFINE_SEMAPHORE() to take a number argument
  module: fix kmemleak annotations for non init ELF sections
  module: Ignore L0 and rename is_arm_mapping_symbol()
  module: Move is_arm_mapping_symbol() to module_symbol.h
  module: Sync code of is_arm_mapping_symbol()
  scripts/gdb: use mem instead of core_layout to get the module address
  interconnect: remove module-related code
  interconnect: remove MODULE_LICENSE in non-modules
  zswap: remove MODULE_LICENSE in non-modules
  zpool: remove MODULE_LICENSE in non-modules
  x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
  ...
2023-04-27 16:36:55 -07:00
Peter Zijlstra
48380368de Change DEFINE_SEMAPHORE() to take a number argument
Fundamentally semaphores are a counted primitive, but
DEFINE_SEMAPHORE() does not expose this and explicitly creates a
binary semaphore.

Change DEFINE_SEMAPHORE() to take a number argument and use that in the
few places that open-coded it using __SEMAPHORE_INITIALIZER().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[mcgrof: add some tribal knowledge about why some folks prefer
 binary sempahores over mutexes]
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-18 11:15:24 -07:00
Fenghua Yu
d7ce15e1d4 x86/split_lock: Enumerate architectural split lock disable bit
The December 2022 edition of the Intel Instruction Set Extensions manual
defined that the split lock disable bit in the IA32_CORE_CAPABILITIES MSR
is (and retrospectively always has been) architectural.

Remove all the model specific checks except for Ice Lake variants which are
still needed because these CPU models do not enumerate presence of the
IA32_CORE_CAPABILITIES MSR.

Originally-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/lkml/20220701131958.687066-1-fenghua.yu@intel.com/t/#mada243bee0915532a6adef6a9e32d244d1a9aef4
2023-03-16 11:50:51 +01:00
Linus Torvalds
a70210f415 - Add support for multiple testing sequences to the Intel In-Field Scan
driver in order to be able to run multiple different test patterns.
 Rework things and remove the BROKEN dependency so that the driver can be
 enabled (Jithu Joseph)
 
 - Remove the subsys interface usage in the microcode loader because it
 is not really needed
 
 - A couple of smaller fixes and cleanups
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Merge tag 'x86_microcode_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 microcode and IFS updates from Borislav Petkov:
 "The IFS (In-Field Scan) stuff goes through tip because the IFS driver
  uses the same structures and similar functionality as the microcode
  loader and it made sense to route it all through this branch so that
  there are no conflicts.

   - Add support for multiple testing sequences to the Intel In-Field
     Scan driver in order to be able to run multiple different test
     patterns. Rework things and remove the BROKEN dependency so that
     the driver can be enabled (Jithu Joseph)

   - Remove the subsys interface usage in the microcode loader because
     it is not really needed

   - A couple of smaller fixes and cleanups"

* tag 'x86_microcode_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86/microcode/intel: Do not retry microcode reloading on the APs
  x86/microcode/intel: Do not print microcode revision and processor flags
  platform/x86/intel/ifs: Add missing kernel-doc entry
  Revert "platform/x86/intel/ifs: Mark as BROKEN"
  Documentation/ABI: Update IFS ABI doc
  platform/x86/intel/ifs: Add current_batch sysfs entry
  platform/x86/intel/ifs: Remove reload sysfs entry
  platform/x86/intel/ifs: Add metadata validation
  platform/x86/intel/ifs: Use generic microcode headers and functions
  platform/x86/intel/ifs: Add metadata support
  x86/microcode/intel: Use a reserved field for metasize
  x86/microcode/intel: Add hdr_type to intel_microcode_sanity_check()
  x86/microcode/intel: Reuse microcode_sanity_check()
  x86/microcode/intel: Use appropriate type in microcode_sanity_check()
  x86/microcode/intel: Reuse find_matching_signature()
  platform/x86/intel/ifs: Remove memory allocation from load path
  platform/x86/intel/ifs: Remove image loading during init
  platform/x86/intel/ifs: Return a more appropriate error code
  platform/x86/intel/ifs: Remove unused selection
  x86/microcode: Drop struct ucode_cpu_info.valid
  ...
2022-12-13 15:05:29 -08:00
Jithu Joseph
e0788c3281 x86/microcode/intel: Add hdr_type to intel_microcode_sanity_check()
IFS test images and microcode blobs use the same header format.
Microcode blobs use header type of 1, whereas IFS test images
will use header type of 2.

In preparation for IFS reusing intel_microcode_sanity_check(),
add header type as a parameter for sanity check.

  [ bp: Touchups. ]

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-9-jithu.joseph@intel.com
2022-11-18 22:08:19 +01:00
Jithu Joseph
514ee839c6 x86/microcode/intel: Reuse microcode_sanity_check()
IFS test image carries the same microcode header as regular Intel
microcode blobs.

Reuse microcode_sanity_check() in the IFS driver to perform sanity check
of the IFS test images too.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-8-jithu.joseph@intel.com
2022-11-18 22:00:17 +01:00
Jithu Joseph
716f380275 x86/microcode/intel: Reuse find_matching_signature()
IFS uses test images provided by Intel that can be regarded as firmware.
An IFS test image carries microcode header with an extended signature
table.

Reuse find_matching_signature() for verifying if the test image header
or the extended signature table indicate whether that image is fit to
run on a system.

No functional changes.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-6-jithu.joseph@intel.com
2022-11-18 21:50:01 +01:00
Guilherme G. Piccoli
727209376f x86/split_lock: Add sysctl to control the misery mode
Commit b041b525da ("x86/split_lock: Make life miserable for split lockers")
changed the way the split lock detector works when in "warn" mode;
basically, it not only shows the warn message, but also intentionally
introduces a slowdown through sleeping plus serialization mechanism
on such task. Based on discussions in [0], seems the warning alone
wasn't enough motivation for userspace developers to fix their
applications.

This slowdown is enough to totally break some proprietary (aka.
unfixable) userspace[1].

Happens that originally the proposal in [0] was to add a new mode
which would warns + slowdown the "split locking" task, keeping the
old warn mode untouched. In the end, that idea was discarded and
the regular/default "warn" mode now slows down the applications. This
is quite aggressive with regards proprietary/legacy programs that
basically are unable to properly run in kernel with this change.
While it is understandable that a malicious application could DoS
by split locking, it seems unacceptable to regress old/proprietary
userspace programs through a default configuration that previously
worked. An example of such breakage was reported in [1].

Add a sysctl to allow controlling the "misery mode" behavior, as per
Thomas suggestion on [2]. This way, users running legacy and/or
proprietary software are allowed to still execute them with a decent
performance while still observing the warning messages on kernel log.

[0] https://lore.kernel.org/lkml/20220217012721.9694-1-tony.luck@intel.com/
[1] https://github.com/doitsujin/dxvk/issues/2938
[2] https://lore.kernel.org/lkml/87pmf4bter.ffs@tglx/

[ dhansen: minor changelog tweaks, including clarifying the actual
  	   problem ]

Fixes: b041b525da ("x86/split_lock: Make life miserable for split lockers")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Andre Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/all/20221024200254.635256-1-gpiccoli%40igalia.com
2022-11-10 10:14:22 -08:00
Borislav Petkov
254ed7cf4d x86/microcode: Drop struct ucode_cpu_info.valid
It is not needed anymore.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Link: https://lore.kernel.org/r/20221028142638.28498-6-bp@alien8.de
2022-11-02 16:45:46 +01:00
Chenyi Qiang
ffa6482e46 x86/bus_lock: Don't assume the init value of DEBUGCTLMSR.BUS_LOCK_DETECT to be zero
It's possible that this kernel has been kexec'd from a kernel that
enabled bus lock detection, or (hypothetically) BIOS/firmware has set
DEBUGCTLMSR_BUS_LOCK_DETECT.

Disable bus lock detection explicitly if not wanted.

Fixes: ebb1064e7c ("x86/traps: Handle #DB for bus lock")
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20220802033206.21333-1-chenyi.qiang@intel.com
2022-08-02 13:42:00 +02:00
Linus Torvalds
42efa5e3a8 - Remove the vendor check when selecting MWAIT as the default idle state
- Respect idle=nomwait when supplied on the kernel cmdline
 
 - Two small cleanups
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Merge tag 'x86_cpu_for_v6.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu updates from Borislav Petkov:

 - Remove the vendor check when selecting MWAIT as the default idle
   state

 - Respect idle=nomwait when supplied on the kernel cmdline

 - Two small cleanups

* tag 'x86_cpu_for_v6.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Use MSR_IA32_MISC_ENABLE constants
  x86: Fix comment for X86_FEATURE_ZEN
  x86: Remove vendor checks from prefer_mwait_c1_over_halt
  x86: Handle idle=nomwait cmdline properly for x86_idle
2022-08-01 09:49:29 -07:00
Paolo Bonzini
3f2adf00f5 x86/cpu: Use MSR_IA32_MISC_ENABLE constants
Instead of the magic numbers 1<<11 and 1<<12 use the constants
from msr-index.h.  This makes it obvious where those bits
of MSR_IA32_MISC_ENABLE are consumed (and in fact that Linux
consumes them at all) to simple minds that grep for
MSR_IA32_MISC_ENABLE_.*_UNAVAIL.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220719174714.2410374-1-pbonzini@redhat.com
2022-07-19 20:53:10 +02:00
Linus Torvalds
8443516da6 platform-drivers-x86 for v5.19-1
Highlights:
  -  New drivers:
     -  Intel "In Field Scan" (IFS) support
     -  Winmate FM07/FM07P buttons
     -  Mellanox SN2201 support
  -  AMD PMC driver enhancements
  -  Lots of various other small fixes and hardware-id additions
 
 The following is an automated git shortlog grouped by driver:
 
 Documentation:
  -  In-Field Scan
 
 Documentation/ABI:
  -  Add new attributes for mlxreg-io sysfs interfaces
  -  sysfs-class-firmware-attributes: Misc. cleanups
  -  sysfs-class-firmware-attributes: Fix Sphinx errors
  -  sysfs-driver-intel_sdsi: Fix sphinx warnings
 
 acerhdf:
  -  Cleanup str_starts_with()
 
 amd-pmc:
  -  Fix build error unused-function
  -  Shuffle location of amd_pmc_get_smu_version()
  -  Avoid reading SMU version at probe time
  -  Move FCH init to first use
  -  Move SMU logging setup out of init
  -  Fix compilation without CONFIG_SUSPEND
 
 amd_hsmp:
  -  Add HSMP protocol version 5 messages
 
 asus-nb-wmi:
  -  Add keymap for MyASUS key
 
 asus-wmi:
  -  Update unknown code message
  -  Use kobj_to_dev()
  -  Fix driver not binding when fan curve control probe fails
  -  Potential buffer overflow in asus_wmi_evaluate_method_buf()
 
 barco-p50-gpio:
  -  Fix duplicate included linux/io.h
 
 dell-laptop:
  -  Add quirk entry for Latitude 7520
 
 gigabyte-wmi:
  -  Add support for Z490 AORUS ELITE AC and X570 AORUS ELITE WIFI
  -  added support for B660 GAMING X DDR4 motherboard
 
 hp-wmi:
  -  Correct code style related issues
 
 intel-hid:
  -  fix _DSM function index handling
 
 intel-uncore-freq:
  -  Prevent driver loading in guests
 
 intel_cht_int33fe:
  -  Set driver data
 
 platform/mellanox:
  -  Add support for new SN2201 system
 
 platform/surface:
  -  aggregator: Fix initialization order when compiling as builtin module
  -  gpe: Add support for Surface Pro 8
 
 platform/x86/dell:
  -  add buffer allocation/free functions for SMI calls
 
 platform/x86/intel:
  -  Fix 'rmmod pmt_telemetry' panic
  -  pmc/core: Use kobj_to_dev()
  -  pmc/core: change pmc_lpm_modes to static
 
 platform/x86/intel/ifs:
  -  Add CPU_SUP_INTEL dependency
  -  add ABI documentation for IFS
  -  Add IFS sysfs interface
  -  Add scan test support
  -  Authenticate and copy to secured memory
  -  Check IFS Image sanity
  -  Read IFS firmware image
  -  Add stub driver for In-Field Scan
 
 platform/x86/intel/sdsi:
  -  Fix bug in multi packet reads
  -  Poll on ready bit for writes
  -  Handle leaky bucket
 
 platform_data/mlxreg:
  -  Add field for notification callback
 
 pmc_atom:
  -  dont export pmc_atom_read - no modular users
  -  remove unused pmc_atom_write()
 
 samsung-laptop:
  -  use kobj_to_dev()
  -  Fix an unsigned comparison which can never be negative
 
 stop_machine:
  -  Add stop_core_cpuslocked() for per-core operations
 
 think-lmi:
  -  certificate support clean ups
 
 thinkpad_acpi:
  -  Correct dual fan probe
  -  Add a s2idle resume quirk for a number of laptops
  -  Convert btusb DMI list to quirks
 
 tools/power/x86/intel-speed-select:
  -  Fix warning for perf_cap.cpu
  -  Display error on turbo mode disabled
  -  fix build failure when using -Wl,--as-needed
 
 toshiba_acpi:
  -  use kobj_to_dev()
 
 trace:
  -  platform/x86/intel/ifs: Add trace point to track Intel IFS operations
 
 winmate-fm07-keys:
  -  Winmate FM07/FM07P buttons
 
 wmi:
  -  replace usage of found with dedicated list iterator variable
 
 x86/microcode/intel:
  -  Expose collect_cpu_info_early() for IFS
 
 x86/msr-index:
  -  Define INTEGRITY_CAPABILITIES MSR
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Merge tag 'platform-drivers-x86-v5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver updates from Hans de Goede:
 "This includes some small changes to kernel/stop_machine.c and arch/x86
  which are deps of the new Intel IFS support.

  Highlights:

   - New drivers:
       - Intel "In Field Scan" (IFS) support
       - Winmate FM07/FM07P buttons
       - Mellanox SN2201 support

   -  AMD PMC driver enhancements

   -  Lots of various other small fixes and hardware-id additions"

* tag 'platform-drivers-x86-v5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (54 commits)
  platform/x86/intel/ifs: Add CPU_SUP_INTEL dependency
  platform/x86: intel_cht_int33fe: Set driver data
  platform/x86: intel-hid: fix _DSM function index handling
  platform/x86: toshiba_acpi: use kobj_to_dev()
  platform/x86: samsung-laptop: use kobj_to_dev()
  platform/x86: gigabyte-wmi: Add support for Z490 AORUS ELITE AC and X570 AORUS ELITE WIFI
  tools/power/x86/intel-speed-select: Fix warning for perf_cap.cpu
  tools/power/x86/intel-speed-select: Display error on turbo mode disabled
  Documentation: In-Field Scan
  platform/x86/intel/ifs: add ABI documentation for IFS
  trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations
  platform/x86/intel/ifs: Add IFS sysfs interface
  platform/x86/intel/ifs: Add scan test support
  platform/x86/intel/ifs: Authenticate and copy to secured memory
  platform/x86/intel/ifs: Check IFS Image sanity
  platform/x86/intel/ifs: Read IFS firmware image
  platform/x86/intel/ifs: Add stub driver for In-Field Scan
  stop_machine: Add stop_core_cpuslocked() for per-core operations
  x86/msr-index: Define INTEGRITY_CAPABILITIES MSR
  x86/microcode/intel: Expose collect_cpu_info_early() for IFS
  ...
2022-05-23 20:38:39 -07:00
Linus Torvalds
abc8babefb - A gargen variety of fixes which don't fit any other tip bucket:
- Remove function export
  - Correct asm constraint
  - Fix __setup handlers retval
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Merge tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 updates from Borislav Petkov:
 "A variety of fixes which don't fit any other tip bucket:

   - Remove unnecessary function export

   - Correct asm constraint

   - Fix __setup handlers retval"

* tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Cleanup the control_va_addr_alignment() __setup handler
  x86: Fix return value of __setup handlers
  x86/delay: Fix the wrong asm constraint in delay_loop()
  x86/amd_nb: Unexport amd_cache_northbridges()
2022-05-23 19:32:59 -07:00
Jithu Joseph
d3287fb0d3 x86/microcode/intel: Expose collect_cpu_info_early() for IFS
IFS is a CPU feature that allows a binary blob, similar to microcode,
to be loaded and consumed to perform low level validation of CPU
circuitry. In fact, it carries the same Processor Signature
(family/model/stepping) details that are contained in Intel microcode
blobs.

In support of an IFS driver to trigger loading, validation, and running
of these tests blobs, make the functionality of cpu_signatures_match()
and collect_cpu_info_early() available outside of the microcode driver.

Add an "intel_" prefix and drop the "_early" suffix from
collect_cpu_info_early() and EXPORT_SYMBOL_GPL() it. Add
declaration to x86 <asm/cpu.h>

Make cpu_signatures_match() an inline function in x86 <asm/cpu.h>,
and also give it an "intel_" prefix.

No functional change intended.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220506225410.1652287-2-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00
Randy Dunlap
12441ccdf5 x86: Fix return value of __setup handlers
__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled. A return
of 0 causes the boot option/value to be listed as an Unknown kernel
parameter and added to init's (limited) argument (no '=') or environment
(with '=') strings. So return 1 from these x86 __setup handlers.

Examples:

  Unknown kernel command line parameters "apicpmtimer
    BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable", will be
    passed to user space.

  Run /sbin/init as init process
   with arguments:
     /sbin/init
     apicpmtimer
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc8
     vdso=1
     ring3mwait=disable

Fixes: 2aae950b21 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu")
Fixes: 77b52b4c5c ("x86: add "debugpat" boot option")
Fixes: e16fd002af ("x86/cpufeature: Enable RING3MWAIT for Knights Landing")
Fixes: b8ce335906 ("x86_64: convert to clock events")
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lore.kernel.org/r/20220314012725.26661-1-rdunlap@infradead.org
2022-05-04 16:47:57 +02:00
Tony Luck
0180a1e823 x86/split_lock: Enable the split lock feature on Raptor Lake
Raptor Lake supports the split lock detection feature. Add it to
the split_lock_cpu_ids[] array.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220427231059.293086-1-tony.luck@intel.com
2022-05-04 12:11:25 +02:00
Tony Luck
ef79970d7c x86/split-lock: Remove unused TIF_SLD bit
Changes to the "warn" mode of split lock handling mean that TIF_SLD is
never set.

Remove the bit, and the functions that use it.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220310204854.31752-3-tony.luck@intel.com
2022-04-27 15:43:39 +02:00
Tony Luck
b041b525da x86/split_lock: Make life miserable for split lockers
In https://lore.kernel.org/all/87y22uujkm.ffs@tglx/ Thomas
said:

  Its's simply wishful thinking that stuff gets fixed because of a
  WARN_ONCE(). This has never worked. The only thing which works is to
  make stuff fail hard or slow it down in a way which makes it annoying
  enough to users to complain.

He was talking about WBINVD. But it made me think about how we use the
split lock detection feature in Linux.

Existing code has three options for applications:

 1) Don't enable split lock detection (allow arbitrary split locks)
 2) Warn once when a process uses split lock, but let the process
    keep running with split lock detection disabled
 3) Kill process that use split locks

Option 2 falls into the "wishful thinking" territory that Thomas warns does
nothing. But option 3 might not be viable in a situation with legacy
applications that need to run.

Hence make option 2 much stricter to "slow it down in a way which makes
it annoying".

Primary reason for this change is to provide better quality of service to
the rest of the applications running on the system. Internal testing shows
that even with many processes splitting locks, performance for the rest of
the system is much more responsive.

The new "warn" mode operates like this.  When an application tries to
execute a bus lock the #AC handler.

 1) Delays (interruptibly) 10 ms before moving to next step.

 2) Blocks (interruptibly) until it can get the semaphore
	If interrupted, just return. Assume the signal will either
	kill the task, or direct execution away from the instruction
	that is trying to get the bus lock.
 3) Disables split lock detection for the current core
 4) Schedules a work queue to re-enable split lock detect in 2 jiffies
 5) Returns

The work queue that re-enables split lock detection also releases the
semaphore.

There is a corner case where a CPU may be taken offline while split lock
detection is disabled. A CPU hotplug handler handles this case.

Old behaviour was to only print the split lock warning on the first
occurrence of a split lock from a task. Preserve that by adding a flag to
the task structure that suppresses subsequent split lock messages from that
task.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220310204854.31752-2-tony.luck@intel.com
2022-04-27 15:43:38 +02:00
Pawan Gupta
400331f8ff x86/tsx: Disable TSX development mode at boot
A microcode update on some Intel processors causes all TSX transactions
to always abort by default[*]. Microcode also added functionality to
re-enable TSX for development purposes. With this microcode loaded, if
tsx=on was passed on the cmdline, and TSX development mode was already
enabled before the kernel boot, it may make the system vulnerable to TSX
Asynchronous Abort (TAA).

To be on safer side, unconditionally disable TSX development mode during
boot. If a viable use case appears, this can be revisited later.

  [*]: Intel TSX Disable Update for Selected Processors, doc ID: 643557

  [ bp: Drop unstable web link, massage heavily. ]

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/347bd844da3a333a9793c6687d4e4eb3b2419a3e.1646943780.git.pawan.kumar.gupta@linux.intel.com
2022-04-11 09:58:40 +02:00
Pawan Gupta
258f3b8c32 x86/tsx: Use MSR_TSX_CTRL to clear CPUID bits
tsx_clear_cpuid() uses MSR_TSX_FORCE_ABORT to clear CPUID.RTM and
CPUID.HLE. Not all CPUs support MSR_TSX_FORCE_ABORT, alternatively use
MSR_IA32_TSX_CTRL when supported.

  [ bp: Document how and why TSX gets disabled. ]

Fixes: 293649307e ("x86/tsx: Clear CPUID bits when TSX always force aborts")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/5b323e77e251a9c8bcdda498c5cc0095be1e1d3c.1646943780.git.pawan.kumar.gupta@linux.intel.com
2022-04-11 09:54:34 +02:00
Linus Torvalds
1b1cf8fe99 Changes in this cycle were:
- Add the "ratelimit:N" parameter to the split_lock_detect= boot option,
    to rate-limit the generation of bus-lock exceptions. This is both
    easier on system resources and kinder to offending applications than
    the current policy of outright killing them.
 
  - Document the split-lock detection feature and its parameters.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-splitlock-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 splitlock updates from Ingo Molnar:

 - Add the "ratelimit:N" parameter to the split_lock_detect= boot
   option, to rate-limit the generation of bus-lock exceptions.

   This is both easier on system resources and kinder to offending
   applications than the current policy of outright killing them.

 - Document the split-lock detection feature and its parameters.

* tag 'x86-splitlock-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/x86: Add ratelimit in buslock.rst
  Documentation/admin-guide: Add bus lock ratelimit
  x86/bus_lock: Set rate limit for bus lock
  Documentation/x86: Add buslock.rst
2021-06-28 13:30:02 -07:00
Pawan Gupta
293649307e x86/tsx: Clear CPUID bits when TSX always force aborts
As a result of TSX deprecation, some processors always abort TSX
transactions by default after a microcode update.

When TSX feature cannot be used it is better to hide it. Clear CPUID.RTM
and CPUID.HLE bits when TSX transactions always abort.

 [ bp: Massage commit message and comments. ]

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Link: https://lkml.kernel.org/r/5209b3d72ffe5bd3cafdcc803f5b883f785329c3.1623704845.git-series.pawan.kumar.gupta@linux.intel.com
2021-06-15 17:46:48 +02:00
Fenghua Yu
ef4ae6e441 x86/bus_lock: Set rate limit for bus lock
A bus lock can be thousands of cycles slower than atomic operation within
one cache line. It also disrupts performance on other cores. Malicious
users can generate multiple bus locks to degrade the whole system
performance.

The current mitigation is to kill the offending process, but for certain
scenarios it's desired to identify and throttle the offending application.

Add a system wide rate limit for bus locks. When the system detects bus
locks at a rate higher than N/sec (where N can be set by the kernel boot
argument in the range [1..1000]) any task triggering a bus lock will be
forced to sleep for at least 20ms until the overall system rate of bus
locks drops below the threshold.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210419214958.4035512-3-fenghua.yu@intel.com
2021-05-18 16:39:31 +02:00
Linus Torvalds
42dec9a936 Perf events changes in this cycle were:
- Improve Intel uncore PMU support:
 
      - Parse uncore 'discovery tables' - a new hardware capability enumeration method
        introduced on the latest Intel platforms. This table is in a well-defined PCI
        namespace location and is read via MMIO. It is organized in an rbtree.
 
        These uncore tables will allow the discovery of standard counter blocks, but
        fancier counters still need to be enumerated explicitly.
 
      - Add Alder Lake support
 
      - Improve IIO stacks to PMON mapping support on Skylake servers
 
  - Add Intel Alder Lake PMU support - which requires the introduction of 'hybrid' CPUs
    and PMUs. Alder Lake is a mix of Golden Cove ('big') and Gracemont ('small' - Atom derived)
    cores.
 
    The CPU-side feature set is entirely symmetrical - but on the PMU side there's
    core type dependent PMU functionality.
 
  - Reduce data loss with CPU level hardware tracing on Intel PT / AUX profiling, by
    fixing the AUX allocation watermark logic.
 
  - Improve ring buffer allocation on NUMA systems
 
  - Put 'struct perf_event' into their separate kmem_cache pool
 
  - Add support for synchronous signals for select perf events. The immediate motivation
    is to support low-overhead sampling-based race detection for user-space code. The
    feature consists of the following main changes:
 
     - Add thread-only event inheritance via perf_event_attr::inherit_thread, which limits
       inheritance of events to CLONE_THREAD.
 
     - Add the ability for events to not leak through exec(), via perf_event_attr::remove_on_exec.
 
     - Allow the generation of SIGTRAP via perf_event_attr::sigtrap, extend siginfo with an u64
       ::si_perf, and add the breakpoint information to ::si_addr and ::si_perf if the event is
       PERF_TYPE_BREAKPOINT.
 
    The siginfo support is adequate for breakpoints right now - but the new field can be used
    to introduce support for other types of metadata passed over siginfo as well.
 
  - Misc fixes, cleanups and smaller updates.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf event updates from Ingo Molnar:

 - Improve Intel uncore PMU support:

     - Parse uncore 'discovery tables' - a new hardware capability
       enumeration method introduced on the latest Intel platforms. This
       table is in a well-defined PCI namespace location and is read via
       MMIO. It is organized in an rbtree.

       These uncore tables will allow the discovery of standard counter
       blocks, but fancier counters still need to be enumerated
       explicitly.

     - Add Alder Lake support

     - Improve IIO stacks to PMON mapping support on Skylake servers

 - Add Intel Alder Lake PMU support - which requires the introduction of
   'hybrid' CPUs and PMUs. Alder Lake is a mix of Golden Cove ('big')
   and Gracemont ('small' - Atom derived) cores.

   The CPU-side feature set is entirely symmetrical - but on the PMU
   side there's core type dependent PMU functionality.

 - Reduce data loss with CPU level hardware tracing on Intel PT / AUX
   profiling, by fixing the AUX allocation watermark logic.

 - Improve ring buffer allocation on NUMA systems

 - Put 'struct perf_event' into their separate kmem_cache pool

 - Add support for synchronous signals for select perf events. The
   immediate motivation is to support low-overhead sampling-based race
   detection for user-space code. The feature consists of the following
   main changes:

     - Add thread-only event inheritance via
       perf_event_attr::inherit_thread, which limits inheritance of
       events to CLONE_THREAD.

     - Add the ability for events to not leak through exec(), via
       perf_event_attr::remove_on_exec.

     - Allow the generation of SIGTRAP via perf_event_attr::sigtrap,
       extend siginfo with an u64 ::si_perf, and add the breakpoint
       information to ::si_addr and ::si_perf if the event is
       PERF_TYPE_BREAKPOINT.

   The siginfo support is adequate for breakpoints right now - but the
   new field can be used to introduce support for other types of
   metadata passed over siginfo as well.

 - Misc fixes, cleanups and smaller updates.

* tag 'perf-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  signal, perf: Add missing TRAP_PERF case in siginfo_layout()
  signal, perf: Fix siginfo_t by avoiding u64 on 32-bit architectures
  perf/x86: Allow for 8<num_fixed_counters<16
  perf/x86/rapl: Add support for Intel Alder Lake
  perf/x86/cstate: Add Alder Lake CPU support
  perf/x86/msr: Add Alder Lake CPU support
  perf/x86/intel/uncore: Add Alder Lake support
  perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
  perf/x86/intel: Add Alder Lake Hybrid support
  perf/x86: Support filter_match callback
  perf/x86/intel: Add attr_update for Hybrid PMUs
  perf/x86: Add structures for the attributes of Hybrid PMUs
  perf/x86: Register hybrid PMUs
  perf/x86: Factor out x86_pmu_show_pmu_cap
  perf/x86: Remove temporary pmu assignment in event_init
  perf/x86/intel: Factor out intel_pmu_check_extra_regs
  perf/x86/intel: Factor out intel_pmu_check_event_constraints
  perf/x86/intel: Factor out intel_pmu_check_num_counters
  perf/x86: Hybrid PMU support for extra_regs
  perf/x86: Hybrid PMU support for event constraints
  ...
2021-04-28 13:03:44 -07:00
Linus Torvalds
64f8e73de0 Support for enhanced split lock detection:
Newer CPUs provide a second mechanism to detect operations with lock
   prefix which go accross a cache line boundary. Such operations have to
   take bus lock which causes a system wide performance degradation when
   these operations happen frequently.
 
   The new mechanism is not using the #AC exception. It triggers #DB and is
   restricted to operations in user space. Kernel side split lock access can
   only be detected by the #AC based variant. Contrary to the #AC based
   mechanism the #DB based variant triggers _after_ the instruction was
   executed. The mechanism is CPUID enumerated and contrary to the #AC
   version which is based on the magic TEST_CTRL_MSR and model/family based
   enumeration on the way to become architectural.
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Merge tag 'x86-splitlock-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 bus lock detection updates from Thomas Gleixner:
 "Support for enhanced split lock detection:

  Newer CPUs provide a second mechanism to detect operations with lock
  prefix which go accross a cache line boundary. Such operations have to
  take bus lock which causes a system wide performance degradation when
  these operations happen frequently.

  The new mechanism is not using the #AC exception. It triggers #DB and
  is restricted to operations in user space. Kernel side split lock
  access can only be detected by the #AC based variant.

  Contrary to the #AC based mechanism the #DB based variant triggers
  _after_ the instruction was executed. The mechanism is CPUID
  enumerated and contrary to the #AC version which is based on the magic
  TEST_CTRL_MSR and model/family based enumeration on the way to become
  architectural"

* tag 'x86-splitlock-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/admin-guide: Change doc for split_lock_detect parameter
  x86/traps: Handle #DB for bus lock
  x86/cpufeatures: Enumerate #DB for bus lock detection
2021-04-26 10:09:38 -07:00
Ricardo Neri
250b3c0d79 x86/cpu: Add helper function to get the type of the current hybrid CPU
On processors with Intel Hybrid Technology (i.e., one having more than
one type of CPU in the same package), all CPUs support the same
instruction set and enumerate the same features on CPUID. Thus, all
software can run on any CPU without restrictions. However, there may be
model-specific differences among types of CPUs. For instance, each type
of CPU may support a different number of performance counters. Also,
machine check error banks may be wired differently. Even though most
software will not care about these differences, kernel subsystems
dealing with these differences must know.

Add and expose a new helper function get_this_hybrid_cpu_type() to query
the type of the current hybrid CPU. The function will be used later in
the perf subsystem.

The Intel Software Developer's Manual defines the CPU type as 8-bit
identifier.

Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1618237865-33448-3-git-send-email-kan.liang@linux.intel.com
2021-04-19 20:03:23 +02:00
Fenghua Yu
ebb1064e7c x86/traps: Handle #DB for bus lock
Bus locks degrade performance for the whole system, not just for the CPU
that requested the bus lock. Two CPU features "#AC for split lock" and
"#DB for bus lock" provide hooks so that the operating system may choose
one of several mitigation strategies.

#AC for split lock is already implemented. Add code to use the #DB for
bus lock feature to cover additional situations with new options to
mitigate.

split_lock_detect=
		#AC for split lock		#DB for bus lock

off		Do nothing			Do nothing

warn		Kernel OOPs			Warn once per task and
		Warn once per task and		and continues to run.
		disable future checking
	 	When both features are
		supported, warn in #AC

fatal		Kernel OOPs			Send SIGBUS to user.
		Send SIGBUS to user
		When both features are
		supported, fatal in #AC

ratelimit:N	Do nothing			Limit bus lock rate to
						N per second in the
						current non-root user.

Default option is "warn".

Hardware only generates #DB for bus lock detect when CPL>0 to avoid
nested #DB from multiple bus locks while the first #DB is being handled.
So no need to handle #DB for bus lock detected in the kernel.

#DB for bus lock is enabled by bus lock detection bit 2 in DEBUGCTL MSR
while #AC for split lock is enabled by split lock detection bit 29 in
TEST_CTRL MSR.

Both breakpoint and bus lock in the same instruction can trigger one #DB.
The bus lock is handled before the breakpoint in the #DB handler.

Delivery of #DB for bus lock in userspace clears DR6[11], which is set by
the #DB handler right after reading DR6.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210322135325.682257-3-fenghua.yu@intel.com
2021-03-28 22:52:15 +02:00