Commit Graph

7017 Commits

Author SHA1 Message Date
Linus Torvalds
06cf61899d Merge tag 'x86-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Ingo Molnar:

 - Fix MCE CMCI discovery initialization ordering bug (Breno Leitao)

* tag 'x86-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Set up the polling timer before CMCI discovery
2026-08-08 16:43:07 -07:00
Linus Torvalds
f5fdd6665a Merge tag 'x86_bugs_saferet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
- Add a mitigation for the attack vector of interrupting the saferet
   sequence used in the SRSO mitigation and still poisoning the RSB.

   Do that by emulating the saferet sequence and thus avoiding executing
   a RET instruction.

* tag 'x86_bugs_saferet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bugs: Make Safe-RET robust against interrupt injection
2026-08-05 17:02:58 -07:00
Breno Leitao
a213dfaa25 x86/mce: Set up the polling timer before CMCI discovery
I hit the following on one of my machines:

  mce: CPU0 BANK15 CMCI inherited storm
  ------------[ cut here ]------------
  ODEBUG: assert_init not available (active state 0) object: (____ptrval____) object type: timer_list hint: 0x0
  WARNING: lib/debugobjects.c:632 at debug_object_assert_init+0x178/0x230, CPU#0: swapper/0/0
  CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc5 #3 PREEMPTLAZY
  RIP: 0010:debug_object_assert_init+0x18f/0x230
  Call Trace:
   <TASK>
   __mod_timer
   mce_timer_kick
   cmci_discover
   intel_init_cmci
   mce_intel_feature_init
   mcheck_cpu_init
   identify_cpu
   identify_boot_cpu
   arch_cpu_finalize_init
   start_kernel

A second splat follows right after, from timer_setup() finding that same
timer already queued:

  ODEBUG: init active (active state 0) object: (____ptrval____) object type: timer_list hint: stub_timer+0x0/0x10

This is happening because CMCI storm detection is trying to modify the timer
before latter was properly set up.

Set up the timer first. __mcheck_cpu_setup_timer() only calls timer_setup(),
and depends on neither the generic nor the vendor init.

  [ bp: Massage commit message. ]

Fixes: 1f68ce2a02 ("x86/mce: Handle Intel threshold interrupt storms")
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260803-mce_timer_init-v1-1-9539db424330@debian.org
2026-08-04 15:09:25 -07:00
Pratik Vishwakarma
5207512827 x86/CPU/AMD: Carve out a Zen5 models range
Family 0x1a, model 0xd0..0xd7 belongs to the Zen5 generation. Carve it
out from the larger, Zen6 range where former doesn't belong.

  [ bp: Rewrite commit message, add tags. ]

Fixes: b5f53e6d3d ("x86/CPU/AMD: Add more Zen6 models")
Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260729055459.15904-1-Pratik.Vishwakarma@amd.com
2026-07-29 12:52:27 -07:00
Borislav Petkov (AMD)
7e7f81cf6f x86/bugs: Make Safe-RET robust against interrupt injection
An attacker injecting interrupts while the Safe-RET mitigation executes
on machines affected by SRSO can neutralize the safe return sequence,
potentially leading to data leakage through speculative execution.

Fixup register state as if the Safe-RET sequence executed successfully
by "emulating" it, in a manner of speaking, and avoid executing a RET
instruction after returning from the interrupt.

Co-developed-by: David Kaplan <David.Kaplan@amd.com>
Signed-off-by: David Kaplan <David.Kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2026-07-26 07:21:37 -07:00
Ethan Nelson-Moore
1ecb29b084 x86/cpu: Remove Makefile rule for removed UMC CPU support
Support for UMC CPUs was removed in

  7d328c5de4 ("x86/cpu: Remove CPU_SUP_UMC_32 support"),

but a Makefile rule for the support code remained. Remove it.

Fixes: 7d328c5de4 ("x86/cpu: Remove CPU_SUP_UMC_32 support")
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ahmed S. Darwish <darwi@linutronix.de>
Link: https://patch.msgid.link/20260610033252.164571-1-enelsonmoore@gmail.com
2026-07-11 18:07:30 -07:00
Linus Torvalds
f105f3631d Merge tag 'x86-urgent-2026-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Ingo Molnar:

 - Prevent OOB access in the resctrl code while offlining
   CPUs when Intel SNC (Sub-NUMA Clustering) is enabled
   (Reinette Chatre)

* tag 'x86-urgent-2026-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled
2026-07-05 05:37:46 -10:00
Reinette Chatre
fc16126cc1 x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled
The architecture updates the cpu_mask in a domain's header to track which
online CPUs are associated with the domain. When this mask becomes empty
the architecture initiates offline of the domain that includes calling
on resctrl fs to offline the domain. If it is a monitoring domain in
which LLC occupancy is tracked resctrl fs forces the limbo handler to
clear all busy RMID state associated with the domain.

The limbo handler always reads the current event value associated with a
busy RMID irrespective of it being checked as part of regular "is it still
busy" check or whether it will be forced released anyway. When reading an
RMID on a system with SNC enabled the "logical RMID" is converted to the
"physical RMID" and this conversion requires the NUMA node ID of the
resctrl monitoring domain that is in turn determined by querying the NUMA
node ID of any CPU belonging to the monitoring domain.

When the monitoring domain is going offline its cpu_mask is empty causing
the NUMA node ID query via cpu_to_node() to be done with "nr_cpu_ids" as
argument resulting in an out-of-bounds access.

Refactor the limbo handler to skip reading the RMID when the RMID will
just be forced to no longer be dirty in the domain anyway. Add a safety
check to the architecture's RMID reader to protect against this scenario.

Fixes: e13db55b5a ("x86/resctrl: Introduce snc_nodes_per_l3_cache")
Closes: https://sashiko.dev/#/patchset/cover.1780456704.git.reinette.chatre%40intel.com?part=9
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/16137433df42f85013b2f7a53626795cbd6637b9.1781029125.git.reinette.chatre@intel.com
2026-07-01 13:15:02 -07:00
Pawan Gupta
a3af84b0fa x86/bugs: Enable IBPB flush on BPF JIT allocation
Enable hardening against JIT spraying when Spectre-v2 mitigations are in
use. Specifically, issue an IBPB flush on BPF JIT memory reuse. Skip
enabling the IBPB flush if the BPF dispatcher is already using a retpoline
sequence.

This hardening applies only when BPF-JIT is in use. Guard the enabling
under CONFIG_BPF_JIT so that bugs.c still builds with CONFIG_BPF_JIT=n.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2026-07-01 10:33:38 +02:00
Linus Torvalds
97cc7dc16a Merge tag 'x86_microcode_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode loader updates from Borislav Petkov:

 - Move the zero-revision fixup for AMD microcode to the patch level
   retrieval function and restrict it to Zen family processors, ensuring
   patch level arithmetic always operates on a valid revision

 - Fix an incorrect comment about which CPUID bit is checked when
   determining whether the microcode loader should be disabled

 - Add the latest Intel microcode revision data for a broad range of
   processor models and steppings and add the script which generates the
   header of minimum expected Intel microcode revisions

* tag 'x86_microcode_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/AMD: Move the no-revision fixup to get_patch_level()
  x86/microcode: Fix comment in microcode_loader_disabled()
  scripts/x86/intel: Add a script to update the old microcode list
  x86/microcode/intel: Refresh old_microcode defines with Nov 2025 release
2026-06-16 05:45:36 +05:30
Linus Torvalds
454761e121 Merge tag 'x86_cleanups_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:

 - The usual pile of cleanups and fixlets the cat dragged in

* tag 'x86_cleanups_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Remove obsolete aperfmperf_get_khz() declaration
  x86/pmem: Check for platform_device_alloc() retval
  x86/platform/uv: Use str_enabled_disabled() in uv_nmi_setup_hubless_intr()
  x86/cpu: Keep the PROCESSOR_SELECT menu together
  x86/tlb: Convert copy_from_user() + kstrtouint() to kstrtouint_from_user()
  x86/purgatory: Fix #endif comment
  x86/boot: Get rid of kstrtoull()
  x86/boot/compressed: Use boot_kstrtoul() for hugepages= parsing
2026-06-16 05:41:22 +05:30
Linus Torvalds
3c26a6bc40 Merge tag 'x86_cache_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull x86 resource control updates from Borislav Petkov:
 "Preparatory work for MPAM counter assignment:

   - Simplify the error handling path when creating monitor group event
     configuration directories

   - Make the MBM event filter configurable only on architectures that
     support it and expose this with the respective file modes in the
     event config

   - Disallow the MBA software controller on systems where MBM counters
     are assignable, as it requires continuous bandwidth measurement
     that assignable counters do not guarantee

   - Replace a compile-time Kconfig option for fixed counter assignment
     with a per-architecture runtime property, and expose whether the
     counter assignment mode is changeable to userspace

   - Continue counter allocation across all domains instead of aborting
     at the first failure

   - Document that automatic MBM counter assignment is best effort and
     may not assign counters to all domains

   - Document the behavior of task ID 0 and idle tasks in the resctrl
     tasks file"

* tag 'x86_cache_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  fs/resctrl: Document tasks file behaviour for task id 0 and idle tasks
  fs/resctrl: Document that automatic counter assignment is best effort
  fs/resctrl: Continue counter allocation after failure
  fs/resctrl: Add monitor property 'mbm_cntr_assign_fixed'
  fs/resctrl: Disallow the software controller when MBM counters are assignable
  x86,fs/resctrl: Create 'event_filter' files read only if they're not configurable
  fs/resctrl: Tidy up the error path in resctrl_mkdir_event_configs()
2026-06-16 05:35:40 +05:30
Linus Torvalds
ff5ccdb8d5 Merge tag 'x86-cpu-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull x86 cpuid updates from Ingo Molnar:

 - CPUID API updates (Ahmed S. Darwish):
    - Introduce a centralized CPUID parser
    - Introduce a centralized CPUID data model
    - Introduce <asm/cpuid/leaf_types.h>
    - Rename cpuid_leaf()/cpuid_subleaf() APIs
    - treewide: Explicitly include the x86 CPUID headers

 - Update to x86-cpuid-db v3.1 (Maciej Wieczor-Retman)

 - Continued removal of pre-i586 support and related simplifications
   (Ingo Molnar)

 - Add Intel CPU model number for rugged Panther Lake (Tony Luck)

 - Misc fixes, updates and cleanups by Arnd Bergmann, Chao Gao, Lukas
   Bulwahn, Sohil Mehta, Maciej Wieczor-Retman.

* tag 'x86-cpu-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (25 commits)
  x86/cpu: Make CONFIG_X86_CX8 unconditional
  x86/cpu: Remove unused !CONFIG_X86_TSC code
  x86/cpuid: Update bitfields to x86-cpuid-db v3.1
  tools/x86/kcpuid: Update bitfields to x86-cpuid-db v3.1
  x86/cpu: Make CONFIG_X86_TSC unconditional
  MAINTAINERS: Drop obsolete FPU EMULATOR section
  x86/cpu: Fix a F00F bug warning and clean up surrounding code
  x86/cpu: Add Intel CPU model number for rugged Panther Lake
  x86/cpuid: Introduce a centralized CPUID parser
  x86/cpu: Introduce a centralized CPUID data model
  x86/cpuid: Introduce <asm/cpuid/leaf_types.h>
  x86/cpuid: Rename cpuid_leaf()/cpuid_subleaf() APIs
  x86/cpu: Do not include the CPUID API header in asm/processor.h
  Documentation: core-api/cpu_hotplug: Remove stale cpu0_hotplug docs
  x86/cpu, cpufreq: Remove AMD ELAN support
  x86/fpu: Remove the math-emu/ FPU emulation library
  x86/fpu: Remove the 'no387' boot option
  x86/fpu: Remove MATH_EMULATION and related glue code
  treewide: Explicitly include the x86 CPUID headers
  x86/cpu: Remove the CONFIG_X86_INVD_BUG quirk
  ...
2026-06-15 15:25:17 +05:30
Linus Torvalds
7561361d76 Merge tag 'x86-msr-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull x86/msr updates from Ingo Molnar:

 - Large series to reorganize the rdmsr/wrmsr APIs to remove
   32-bit variants and convert to 64-bit variants (Juergen Gross)

 - Fix W=1 warning (HyeongJun An)

* tag 'x86-msr-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/msr: Remove wrmsrl()
  x86/msr: Switch wrmsrl() users to wrmsrq()
  x86/msr: Remove rdmsrl()
  x86/msr: Switch rdmsrl() users to rdmsrq()
  x86/msr: Remove wrmsr_safe_on_cpu()
  x86/msr: Switch wrmsr_safe_on_cpu() users to wrmsrq_safe_on_cpu()
  x86/msr: Remove rdmsr_safe_on_cpu()
  x86/msr: Switch rdmsr_safe_on_cpu() users to rdmsrq_safe_on_cpu()
  x86/msr: Don't use rdmsr_safe_on_cpu() in rdmsrq_safe_on_cpu()
  x86/msr: Remove wrmsr_on_cpu()
  x86/msr: Switch wrmsr_on_cpu() users to wrmsrq_on_cpu()
  x86/msr: Remove rdmsr_on_cpu()
  x86/msr: Switch rdmsr_on_cpu() users to rdmsrq_on_cpu()
  x86/msr: Remove rdmsrl_on_cpu()
  x86/msr: Switch rdmsrl_on_cpu() user to rdmsrq_on_cpu()
  x86/process: Convert rdmsr() to rdmsrq() in arch_post_acpi_subsys_init() to address W=1 warning
2026-06-15 15:08:14 +05:30
Linus Torvalds
13e1a6d6a1 Merge tag 'irq-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull interrupt core updates from Thomas Gleixner:

  - Rework of /proc/interrupt handling:

    /proc/interrupts was subject to micro optimizations for a long time,
    but most of the low hanging fruit was left on the table. This rework
    addresses the major time consuming issues:

      - Printing a long series of zeros one by one via a format string
        instead of counting subsequent zeros and emitting a string
        constant.

      - Simplify and cache the conditions whether interrupts should be
        printed

      - Use a proper iteration over the interrupt descriptor xarray
        instead of walking and testing one by one.

      - Provide helper functions for the architecture code to emit the
        architecture specific counters

      - Convert the counter structure in x86 to an array, which
        simplifies the output and add mechanisms to suppress unused
        architecture interrupts, which just occupy space for nothing.
        Adopt the new core mechanisms.

    This adjusts the gdb scripts related to interrupt counter statistics
    to work with the new mechanisms.

  - Prevent a string overflow in the /proc/irq/$N/ directory name
    creation code.

* tag 'irq-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/irq: Add missing 's' back to thermal event printout
  genirq/proc: Speed up /proc/interrupts iteration
  genirq/proc: Runtime size the chip name
  genirq: Expose irq_find_desc_at_or_after() in core code
  genirq: Add rcuref count to struct irq_desc
  genirq/proc: Increase default interrupt number precision to four
  genirq: Calculate precision only when required
  genirq: Cache the condition for /proc/interrupts exposure
  genirq/manage: Make NMI cleanup RT safe
  genirq: Expose nr_irqs in core code
  scripts/gdb: Update x86 interrupts to the array based storage
  x86/irq: Move IOAPIC misrouted and PIC/APIC error counts into irq_stats
  x86/irq: Suppress unlikely interrupt stats by default
  x86/irq: Make irqstats array based
  genirq/proc: Utilize irq_desc::tot_count to avoid evaluation
  genirq/proc: Avoid formatting zero counts in /proc/interrupts
  x86/irq: Optimize interrupts decimals printing
  genirq/proc: Size interrupt directory names for 10-digit interrupt numbers
2026-06-15 13:19:41 +05:30
Juergen Gross
2232959db2 x86/msr: Switch wrmsrl() users to wrmsrq()
wrmsrl() is a deprecated synonym for wrmsrq(). Switch its users to
wrmsrq().

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Long Li <longli@microsoft.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20260608082809.3492719-4-jgross@suse.com
2026-06-08 13:16:35 +02:00
Juergen Gross
72ac0e45c2 x86/msr: Switch rdmsrl() users to rdmsrq()
rdmsrl() is a deprecated synonym for rdmsrq(). Switch its users to
rdmsrq().

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Long Li <longli@microsoft.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20260608082809.3492719-2-jgross@suse.com
2026-06-08 13:16:34 +02:00
Juergen Gross
35971831aa x86/msr: Switch wrmsr_on_cpu() users to wrmsrq_on_cpu()
In order to prepare retiring wrmsr_on_cpu() switch wrmsr_on_cpu() users
to wrmsrq_on_cpu().

Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@kernel.org>
Link: https://patch.msgid.link/20260608051741.3207435-6-jgross@suse.com
2026-06-08 10:01:49 +02:00
Juergen Gross
40b57cfbd2 x86/msr: Switch rdmsr_on_cpu() users to rdmsrq_on_cpu()
In order to prepare retiring rdmsr_on_cpu() switch rdmsr_on_cpu() users
to rdmsrq_on_cpu().

Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Daniel Lezcano <daniel.lezcano@kernel.org>
Link: https://patch.msgid.link/20260608051741.3207435-4-jgross@suse.com
2026-06-08 10:01:49 +02:00
Junxiao Chang
a5f28da54f x86/cpu: Remove obsolete aperfmperf_get_khz() declaration
aperfmperf_get_khz() was replaced by arch_freq_get_on_cpu().
The remaining declaration in the header file is no longer used
and should be removed.

Fixes: f3eca381bd ("x86/aperfmperf: Replace arch_freq_get_on_cpu()")
Signed-off-by: Junxiao Chang <junxiao.chang@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Link: https://patch.msgid.link/20260606021514.1433619-1-junxiao.chang@intel.com
2026-06-05 15:10:25 +02:00
Tony Luck
6f6947b238 x86/resctrl: Only check Intel systems for SNC
topology_num_nodes_per_package() reports values greater than one on certain
AMD systems resulting in resctrl's Intel model specific SNC detection
printing the confusing message:

   "CoD enabled system? Resctrl not supported"

Add a check for Intel systems before looking at the topology.

[ reinette: Add Closes tag, fix tag typos, rework changelog ]

Fixes: 59674fc9d0 ("x86/resctrl: Fix SNC detection")
Reported-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://patch.msgid.link/9849330f45ac86344cc5ac54df2d313906d70bc4.1780634584.git.reinette.chatre@intel.com
Closes: https://lore.kernel.org/lkml/37ac0376-43a3-4283-a3d5-4d57b3bec578@amd.com/
2026-06-05 11:09:34 +02:00
Borislav Petkov (AMD)
098bcea71b x86/microcode/AMD: Move the no-revision fixup to get_patch_level()
On machines which don't have microcode applied yet, the revision is 0.
However, this doesn't work with the Zen family/model/stepping patch
arithmetic. So move the fixup to the patch level getter function and
this way make sure the patch level is always proper and thus the
arithmetic always works.

And now that it can be called on any family, make this Zen-only.

Assisted-by: claude/claude-opus-4-6
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20260530024213.86137-1-bp@kernel.org
2026-06-04 08:55:58 -07:00
Pratik Vishwakarma
b5f53e6d3d x86/CPU/AMD: Add more Zen6 models
Family 0x1a, models 0xd0 - 0xef are Zen6, so add them to the range which sets
X86_FEATURE_ZEN6.

  [ bp: Massage commit message. ]

Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260530061819.9721-1-Pratik.Vishwakarma@amd.com
2026-06-01 10:31:09 -07:00
Sohil Mehta
87a451161f x86/cpu: Fix a F00F bug warning and clean up surrounding code
On x86 SMP systems with the F00F bug present, do_clear_cpu_cap()
rightfully warns that the code clears the X86_BUG_F00F flag after
alternatives have been patched.

X86_BUG_F00F is first cleared in intel_workarounds() and then set for
the affected models. This sequence works fine on the BSP but on AP
bringup, where alternatives have already been patched and clearing the
flag there triggers the warning.

There is no technical reason for clearing the flag before setting it. It
is mainly an artifact of introducing the X86_BUG_F00F flag in

  e2604b49e8 ("x86, cpu: Convert F00F bug detection").

Remove the unnecessary clearing of the flag.

While at it, remove the kernel notification and the surrounding logic to
inform the user about the workaround exactly once. If needed, the
presence of the F00F bug can be determined through /proc/cpuinfo.

Additionally, the F00F bug was the last remaining user of clear_cpu_bug().
With no users left, get rid of this helper as well.

  [ bp: Massage commit message. ]

Co-developed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ahmed S. Darwish <darwi@linutronix.de>
Link: https://patch.msgid.link/20260528184826.3642051-1-sohil.mehta@intel.com
2026-05-28 18:41:32 -07:00
Borislav Petkov
cda64169ba x86/microcode: Do not access MSR_IA32_PLATFORM_ID when running as a guest
Patch in Fixes: causes the usual:

  unchecked MSR access error: RDMSR from 0x17 at ... (intel_get_platform_id)
  Call Trace:
   early_init_intel
   early_cpu_init
   setup_arch
   _printk
   start_kernel
   x86_64_start_reservations
   x86_64_start_kernel
   common_startup_64

because the kernel is booted in a guest.

In order to avoid it, this MSR access needs to be prevented when running
virtualized. That is usually done by checking X86_FEATURE_HYPERVISOR but
for this particular case it is too early yet.

The platform ID needs to be read as early as when microcode is loaded on
the BSP:

  load_ucode_bsp ... -> get_microcode_blob ... -> intel_find_matching_signature

and by that time, CPUID leafs haven't been parsed yet.

The microcode loader already has logic to check early whether the kernel
is running virtualized so make that globally available to arch/x86/. The
query whether running virtualized is getting more and more prominent in
recent times so might as well make it an arch-global var which the rest
of the code can use.

Fixes: d8630b67ca ("x86/cpu: Add platform ID to CPU info structure")
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Tested-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/all/20260430020953.1405535-1-binbin.wu@linux.intel.com
2026-05-26 13:36:23 -07:00
Thomas Gleixner
2b57c69917 x86/irq: Make irqstats array based
Having the x86 specific interrupt statistics as a data structure with
individual members instead of an array is just stupid as it requires
endless copy and paste in arch_show_interrupts() and arch_irq_stat_cpu(),
where the latter does not even take the latest interrupt additions into
account. The resulting #ifdef orgy is just disgusting.

Convert it to an array of counters, which does not make a difference in the
actual interrupt hotpath increment as the array index is constant and
therefore not any different than the member based access.

But in arch_show_interrupts() and arch_irq_stat_cpu() this just turns into
a loop, which reduces the text size by ~2k (~12%):

   text	   data	    bss	    dec	    hex	filename
  19643	  15250	    904	  35797	   8bd5	../build/arch/x86/kernel/irq.o
  17355	  15250	    904	  33509	   82e5	../build/arch/x86/kernel/irq.o

Adding a new vector or software counter only requires to update the table
and everything just works. Using the core provided emit function which
speeds up 0 outputs makes it significantly faster.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Radu Rendec <radu@rendec.net>
Link: https://patch.msgid.link/20260517194931.196070643@kernel.org
2026-05-26 16:21:12 +02:00
Tom Lendacky
44126343d5 x86/mm: Disable broadcast TLB flush when PCID is disabled
Booting with "nopcid" clears X86_FEATURE_PCID and keeps CR4.PCIDE from being
set to one. On AMD CPUs that support INVLPGB, broadcast TLB flushing remains
enabled.

There are two checks that decide whether the global ASID code runs,
mm_global_asid() and consider_global_asid(), that key off of the
X86_FEATURE_INVLPGB feature. Once an mm becomes active on more than three
CPUs, consider_global_asid() assigns it a global ASID, after which
flush_tlb_mm_range() takes the broadcast_tlb_flush() path using a non-zero
PCID. Issuing an INVLPGB with a non-zero PCID while CR4.PCIDE is not set
results in a #GP:

  Oops: general protection fault, kernel NULL pointer dereference 0x1: 0000 [#1] SMP NOPTI
  CPU: 158 UID: 0 PID: 3119 Comm: snap Not tainted 7.1.0-rc3 #1 PREEMPT(full)
  Hardware name: ...
  RIP: 0010:broadcast_tlb_flush
  Code: ... 89 da 48 83 c8 07 <0f> 01 fe eb 08 cc cc cc ...
  Call Trace:
   <TASK>
   flush_tlb_mm_range
   ptep_clear_flush
   wp_page_copy
   ? _raw_spin_unlock
   __handle_mm_fault
   handle_mm_fault
   do_user_addr_fault
   exc_page_fault
   asm_exc_page_fault

All processors that support broadcast TLB invalidation also have PCID support,
so it is only the "nopcid" scenario that is of concern. In this situation just
disable the broadcast TLB support using the CPUID dependency support by making
X86_FEATURE_INVLPGB dependent on X86_FEATURE_PCID.

  [ bp: Massage commit message. ]

Fixes: 4afeb0ed17 ("x86/mm: Enable broadcast TLB invalidation for multi-threaded processes")
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Assisted-by: Claude:claude-opus-4.7
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/b915acfd63e8b2a094fdeb8dc608738072518764.1779296450.git.thomas.lendacky@amd.com
2026-05-20 14:15:07 -07:00
Linus Torvalds
daa3de23f9 Merge tag 'ras-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull MCE fix from Ingo Molnar:

 - Fix an MCE polling interval adjustment regression (Borislav Petkov)

* tag 'ras-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Restore MCA polling interval halving
2026-05-17 10:50:13 -07:00
Borislav Petkov (AMD)
ea324444ec x86/mce: Restore MCA polling interval halving
RongQing reported that the MCA polling interval doesn't halve when an
error gets logged. It was traced down to the commit in Fixes:, because:

  mce_timer_fn()
  |-> mce_poll_banks()
  |-> machine_check_poll()
  |-> mce_log()

which will queue the work and return.

Now, back in mce_timer_fn():

        /*
         * Alert userspace if needed. If we logged an MCE, reduce the polling
         * interval, otherwise increase the polling interval.
         */
        if (mce_notify_irq())

<--- here we haven't ran the notifier chain yet so mce_need_notify is
not set yet so this won't hit and we won't halve the interval iv.

Now the notifier chain runs. mce_early_notifier() sets the bit, does
mce_notify_irq(), that clears the bit and then the notifier chain
a little later logs the error.

So this is a silly timing issue.

But, that's all unnecessary.

All it needs to happen here is, the "should we notify of a logged MCE"
mce_notify_irq() asks, should be simply a question to the mce gen pool:
"Are you empty?"

And that then turns into a simple yes or no answer and it all
JustWorks(tm).

So do that and also distribute the functionality where it belongs:
 - Print that MCE events have been logged in mce_log()
 - Trigger the mcelog tool specific work in the first notifier

As a result, mce_notify_irq() can go now.

Fixes: 011d826111 ("RAS: Add a Corrected Errors Collector")
Reported-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Link: https://lore.kernel.org/r/20260112082747.2842-1-lirongqing@baidu.com
2026-05-13 17:38:35 +02:00
Xiaoyao Li
1458ade746 x86/microcode: Fix comment in microcode_loader_disabled()
The code in microcode_loader_disabled() actually checks for the bit 31
in CPUID[1]:ECX being set. Update the comment to match the code.

No functional change intended.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260512152754.671760-1-xiaoyao.li@intel.com
2026-05-12 18:28:04 +02:00
Prathyushi Nangia
c21b90f776 x86/CPU/AMD: Prevent improper isolation of shared resources in Zen2's op cache
Make sure resources are not improperly shared in the op cache and
cause instruction corruption this way.

Signed-off-by: Prathyushi Nangia <prathyushi.nangia@amd.com>
Co-developed-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-05-11 20:06:36 -07:00
Ahmed S. Darwish
fa6dcbc69a x86/cpuid: Introduce a centralized CPUID parser
Introduce a CPUID parser for populating the system's CPUID tables.

Since accessing a leaf within the CPUID table requires compile time
tokenization, split the parser into two stages:

  (a) Compile-time macros for tokenizing the leaf/subleaf offsets within
      the CPUID table.

  (b) Generic runtime code to fill the CPUID data, using a parsing table
      which collects these compile-time offsets.

For actual CPUID output parsing, support both generic and leaf-specific
read functions.

To ensure CPUID data early availability, invoke the parser during early
boot, early Xen boot, and at early secondary CPUs bring up.

Provide call site APIs to refresh a single leaf, or a leaf range, within
the CPUID tables.  This is for sites issuing MSR writes that partially
change the CPU's CPUID layout.  Doing full CPUID table rescans in such
cases will be destructive since the CPUID tables will host all of the
kernel's X86_FEATURE flags at a later stage.

Suggested-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/all/20260327021645.555257-1-darwi@linutronix.de
2026-05-11 16:05:50 +02:00
Ahmed S. Darwish
5fbe09ebb4 x86/cpuid: Rename cpuid_leaf()/cpuid_subleaf() APIs
A new CPUID model will be added where its APIs will be designated as the
official CPUID API.  Free the cpuid_leaf() and cpuid_subleaf() function
names for that API.  Rename them accordingly to cpuid_read() and
cpuid_read_subleaf().

For kernel/cpuid.c, rename its local file operations read function from
cpuid_read() to cpuid_read_f() so that it does not conflict with the new
API.

No functional change.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20260327021645.555257-1-darwi@linutronix.de
2026-05-08 23:10:14 +02:00
Ingo Molnar
d8b55ce0c9 x86/fpu: Remove the 'no387' boot option
Without math emulation there's no point to this option.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ahmed S. Darwish <darwi@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250425084216.3913608-10-mingo@kernel.org
2026-05-08 07:34:03 +02:00
Ben Horgan
94a1206522 x86,fs/resctrl: Create 'event_filter' files read only if they're not configurable
When the counter assignment mode is mbm_event resctrl assumes the MBM
events are configurable and exposes the 'event_filter' files. These files
live at info/L3_MON/event_configs/<event>/event_filter and are used to
display and set the event configuration.

The MPAM architecture has support for configuring the memory bandwidth
utilization (MBWU) counters to only count reads or only count
writes. However, in MPAM, this event filtering support is optional in the
hardware (and not yet implemented in the MPAM driver) but MBM counter
assignment is always possible for MPAM MBWU counters.

In order to support mbm_event mode with MPAM, create the 'event_filter'
files read only if the event configuration can't be changed. A user can
still chmod the file and so also return early with an error from
event_filter_write().

Introduce a new monitor property, mbm_cntr_configurable, to indicate
whether or not assignable MBM counters are configurable. On x86, set this
to true whenever mbm_cntr_assignable is true to keep existing behaviour.

Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/20260506082855.3694761-1-ben.horgan@arm.com
2026-05-06 19:06:57 +02:00
Ahmed S. Darwish
7b49a3fb69 treewide: Explicitly include the x86 CPUID headers
Modify all CPUID call sites which implicitly include any of the CPUID
headers to explicitly include them instead.

For KVM's reverse_cpuid.h, just include <asm/cpuid/types.h> since it
references the CPUID_EAX..EDX symbols without using the CPUID APIs.

Note, this allows removing the inclusion of <asm/cpuid/api.h> from within
<asm/processor.h> next.  That allows the CPUID API headers to include
<asm/processor.h> without introducing a circular dependency.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20260327021645.555257-1-darwi@linutronix.de
2026-05-06 14:29:59 +02:00
Ingo Molnar
7d328c5de4 x86/cpu: Remove CPU_SUP_UMC_32 support
These are 486 based CPUs, which build option (M486) is now gone
upstream.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250425084216.3913608-4-mingo@kernel.org
2026-05-06 08:01:45 +02:00
Sohil Mehta
515c6b2160 x86/microcode/intel: Refresh old_microcode defines with Nov 2025 release
Update the minimum expected revisions of Intel microcode based on the
microcode-20251111 (November 2025) release.

Add an SPDX header as well as a comment to specify that the file is
auto-generated. While at it, remove an extra space before the model
field to match the formatting of the other fields.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20260407014226.1169040-2-sohil.mehta@intel.com
2026-04-29 15:53:19 -07:00
Linus Torvalds
8fd12b03c7 Merge tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull Hyper-V updates from Wei Liu:

 - Fix cross-compilation for hv tools (Aditya Garg)

 - Fix vmemmap_shift exceeding MAX_FOLIO_ORDER in mshv_vtl (Naman Jain)

 - Limit channel interrupt scan to relid high water mark (Michael
   Kelley)

 - Export hv_vmbus_exists() and use it in pci-hyperv (Dexuan Cui)

 - Fix cleanup and shutdown issues for MSHV (Jork Loeser)

 - Introduce more tracing support for MSHV (Stanislav Kinsburskii)

* tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Skip LP/VP creation on kexec
  x86/hyperv: move stimer cleanup to hv_machine_shutdown()
  Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowing
  mshv: Add tracepoint for GPA intercept handling
  mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER
  tools: hv: Fix cross-compilation
  Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv
  mshv: Introduce tracing support
  Drivers: hv: vmbus: Limit channel interrupt scan to relid high water mark
2026-04-22 09:50:46 -07:00
Jork Loeser
5170a82e89 x86/hyperv: Skip LP/VP creation on kexec
After a kexec the logical processors and virtual processors already
exist in the hypervisor because they were created by the previous
kernel. Attempting to add them again causes either a BUG_ON or
corrupted VP state leading to MCEs in the new kernel.

Add hv_lp_exists() to probe whether an LP is already present by
calling HVCALL_GET_LOGICAL_PROCESSOR_RUN_TIME. When it succeeds the
LP exists and we skip the add-LP and create-VP loops entirely.

Also add hv_call_notify_all_processors_started() which informs the
hypervisor that all processors are online. This is required after
adding LPs (fresh boot) and is a no-op on kexec since we skip that
path.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Co-developed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Signed-off-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22 06:23:25 +00:00
Jork Loeser
f7ce370b52 x86/hyperv: move stimer cleanup to hv_machine_shutdown()
Move hv_stimer_global_cleanup() from vmbus's hv_kexec_handler() to
hv_machine_shutdown() in the platform code. This ensures stimer cleanup
happens before the vmbus unload, which is required for root partition
kexec to work correctly.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22 06:23:25 +00:00
Linus Torvalds
01f492e181 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "Arm:

   - Add support for tracing in the standalone EL2 hypervisor code,
     which should help both debugging and performance analysis. This
     uses the new infrastructure for 'remote' trace buffers that can be
     exposed by non-kernel entities such as firmware, and which came
     through the tracing tree

   - Add support for GICv5 Per Processor Interrupts (PPIs), as the
     starting point for supporting the new GIC architecture in KVM

   - Finally add support for pKVM protected guests, where pages are
     unmapped from the host as they are faulted into the guest and can
     be shared back from the guest using pKVM hypercalls. Protected
     guests are created using a new machine type identifier. As the
     elusive guestmem has not yet delivered on its promises, anonymous
     memory is also supported

     This is only a first step towards full isolation from the host; for
     example, the CPU register state and DMA accesses are not yet
     isolated. Because this does not really yet bring fully what it
     promises, it is hidden behind CONFIG_ARM_PKVM_GUEST +
     'kvm-arm.mode=protected', and also triggers TAINT_USER when a VM is
     created. Caveat emptor

   - Rework the dreaded user_mem_abort() function to make it more
     maintainable, reducing the amount of state being exposed to the
     various helpers and rendering a substantial amount of state
     immutable

   - Expand the Stage-2 page table dumper to support NV shadow page
     tables on a per-VM basis

   - Tidy up the pKVM PSCI proxy code to be slightly less hard to
     follow

   - Fix both SPE and TRBE in non-VHE configurations so that they do not
     generate spurious, out of context table walks that ultimately lead
     to very bad HW lockups

   - A small set of patches fixing the Stage-2 MMU freeing in error
     cases

   - Tighten-up accepted SMC immediate value to be only #0 for host
     SMCCC calls

   - The usual cleanups and other selftest churn

  LoongArch:

   - Use CSR_CRMD_PLV for kvm_arch_vcpu_in_kernel()

   - Add DMSINTC irqchip in kernel support

  RISC-V:

   - Fix steal time shared memory alignment checks

   - Fix vector context allocation leak

   - Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi()

   - Fix double-free of sdata in kvm_pmu_clear_snapshot_area()

   - Fix integer overflow in kvm_pmu_validate_counter_mask()

   - Fix shift-out-of-bounds in make_xfence_request()

   - Fix lost write protection on huge pages during dirty logging

   - Split huge pages during fault handling for dirty logging

   - Skip CSR restore if VCPU is reloaded on the same core

   - Implement kvm_arch_has_default_irqchip() for KVM selftests

   - Factored-out ISA checks into separate sources

   - Added hideleg to struct kvm_vcpu_config

   - Factored-out VCPU config into separate sources

   - Support configuration of per-VM HGATP mode from KVM user space

  s390:

   - Support for ESA (31-bit) guests inside nested hypervisors

   - Remove restriction on memslot alignment, which is not needed
     anymore with the new gmap code

   - Fix LPSW/E to update the bear (which of course is the breaking
     event address register)

  x86:

   - Shut up various UBSAN warnings on reading module parameter before
     they were initialized

   - Don't zero-allocate page tables that are used for splitting
     hugepages in the TDP MMU, as KVM is guaranteed to set all SPTEs in
     the page table and thus write all bytes

   - As an optimization, bail early when trying to unsync 4KiB mappings
     if the target gfn can just be mapped with a 2MiB hugepage

  x86 generic:

   - Copy single-chunk MMIO write values into struct kvm_vcpu (more
     precisely struct kvm_mmio_fragment) to fix use-after-free stack
     bugs where KVM would dereference stack pointer after an exit to
     userspace

   - Clean up and comment the emulated MMIO code to try to make it
     easier to maintain (not necessarily "easy", but "easier")

   - Move VMXON+VMXOFF and EFER.SVME toggling out of KVM (not *all* of
     VMX and SVM enabling) as it is needed for trusted I/O

   - Advertise support for AVX512 Bit Matrix Multiply (BMM) instructions

   - Immediately fail the build if a required #define is missing in one
     of KVM's headers that is included multiple times

   - Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected
     exception, mostly to prevent syzkaller from abusing the uAPI to
     trigger WARNs, but also because it can help prevent userspace from
     unintentionally crashing the VM

   - Exempt SMM from CPUID faulting on Intel, as per the spec

   - Misc hardening and cleanup changes

  x86 (AMD):

   - Fix and optimize IRQ window inhibit handling for AVIC; make it
     per-vCPU so that KVM doesn't prematurely re-enable AVIC if multiple
     vCPUs have to-be-injected IRQs

   - Clean up and optimize the OSVW handling, avoiding a bug in which
     KVM would overwrite state when enabling virtualization on multiple
     CPUs in parallel. This should not be a problem because OSVW should
     usually be the same for all CPUs

   - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains
     about a "too large" size based purely on user input

   - Clean up and harden the pinning code for KVM_MEMORY_ENCRYPT_REG_REGION

   - Disallow synchronizing a VMSA of an already-launched/encrypted
     vCPU, as doing so for an SNP guest will crash the host due to an
     RMP violation page fault

   - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped
     queries are required to hold kvm->lock, and enforce it by lockdep.
     Fix various bugs where sev_guest() was not ensured to be stable for
     the whole duration of a function or ioctl

   - Convert a pile of kvm->lock SEV code to guard()

   - Play nicer with userspace that does not enable
     KVM_CAP_EXCEPTION_PAYLOAD, for which KVM needs to set CR2 and DR6
     as a response to ioctls such as KVM_GET_VCPU_EVENTS (even if the
     payload would end up in EXITINFO2 rather than CR2, for example).
     Only set CR2 and DR6 when consumption of the payload is imminent,
     but on the other hand force delivery of the payload in all paths
     where userspace retrieves CR2 or DR6

   - Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT
     instead of vmcb02->save.cr2. The value is out of sync after a
     save/restore or after a #PF is injected into L2

   - Fix a class of nSVM bugs where some fields written by the CPU are
     not synchronized from vmcb02 to cached vmcb12 after VMRUN, and so
     are not up-to-date when saved by KVM_GET_NESTED_STATE

   - Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE
     and KVM_SET_{S}REGS could cause vmcb02 to be incorrectly
     initialized after save+restore

   - Add a variety of missing nSVM consistency checks

   - Fix several bugs where KVM failed to correctly update VMCB fields
     on nested #VMEXIT

   - Fix several bugs where KVM failed to correctly synthesize #UD or
     #GP for SVM-related instructions

   - Add support for save+restore of virtualized LBRs (on SVM)

   - Refactor various helpers and macros to improve clarity and
     (hopefully) make the code easier to maintain

   - Aggressively sanitize fields when copying from vmcb12, to guard
     against unintentionally allowing L1 to utilize yet-to-be-defined
     features

   - Fix several bugs where KVM botched rAX legality checks when
     emulating SVM instructions. There are remaining issues in that KVM
     doesn't handle size prefix overrides for 64-bit guests

   - Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails
     instead of somewhat arbitrarily synthesizing #GP (i.e. don't double
     down on AMD's architectural but sketchy behavior of generating #GP
     for "unsupported" addresses)

   - Cache all used vmcb12 fields to further harden against TOCTOU bugs

  x86 (Intel):

   - Drop obsolete branch hint prefixes from the VMX instruction macros

   - Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a
     register input when appropriate

   - Code cleanups

  guest_memfd:

   - Don't mark guest_memfd folios as accessed, as guest_memfd doesn't
     support reclaim, the memory is unevictable, and there is no storage
     to write back to

  LoongArch selftests:

   - Add KVM PMU test cases

  s390 selftests:

   - Enable more memory selftests

  x86 selftests:

   - Add support for Hygon CPUs in KVM selftests

   - Fix a bug in the MSR test where it would get false failures on
     AMD/Hygon CPUs with exactly one of RDPID or RDTSCP

   - Add an MADV_COLLAPSE testcase for guest_memfd as a regression test
     for a bug where the kernel would attempt to collapse guest_memfd
     folios against KVM's will"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (373 commits)
  KVM: x86: use inlines instead of macros for is_sev_*guest
  x86/virt: Treat SVM as unsupported when running as an SEV+ guest
  KVM: SEV: Goto an existing error label if charging misc_cg for an ASID fails
  KVM: SVM: Move lock-protected allocation of SEV ASID into a separate helper
  KVM: SEV: use mutex guard in snp_handle_guest_req()
  KVM: SEV: use mutex guard in sev_mem_enc_unregister_region()
  KVM: SEV: use mutex guard in sev_mem_enc_ioctl()
  KVM: SEV: use mutex guard in snp_launch_update()
  KVM: SEV: Assert that kvm->lock is held when querying SEV+ support
  KVM: SEV: Document that checking for SEV+ guests when reclaiming memory is "safe"
  KVM: SEV: Hide "struct kvm_sev_info" behind CONFIG_KVM_AMD_SEV=y
  KVM: SEV: WARN on unhandled VM type when initializing VM
  KVM: LoongArch: selftests: Add PMU overflow interrupt test
  KVM: LoongArch: selftests: Add basic PMU event counting test
  KVM: LoongArch: selftests: Add cpucfg read/write helpers
  LoongArch: KVM: Add DMSINTC inject msi to vCPU
  LoongArch: KVM: Add DMSINTC device support
  LoongArch: KVM: Make vcpu_is_preempted() as a macro rather than function
  LoongArch: KVM: Move host CSR_GSTAT save and restore in context switch
  LoongArch: KVM: Move host CSR_EENTRY save and restore in context switch
  ...
2026-04-17 07:18:03 -07:00
Borislav Petkov (AMD)
e55d98e775 x86/CPU: Fix FPDSS on Zen1
Zen1's hardware divider can leave, under certain circumstances, partial
results from previous operations.  Those results can be leaked by
another, attacker thread.

Fix that with a chicken bit.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-04-17 06:04:42 -07:00
Linus Torvalds
334fbe734e Merge tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - "maple_tree: Replace big node with maple copy" (Liam Howlett)

   Mainly prepararatory work for ongoing development but it does reduce
   stack usage and is an improvement.

 - "mm, swap: swap table phase III: remove swap_map" (Kairui Song)

   Offers memory savings by removing the static swap_map. It also yields
   some CPU savings and implements several cleanups.

 - "mm: memfd_luo: preserve file seals" (Pratyush Yadav)

   File seal preservation to LUO's memfd code

 - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan
   Chen)

   Additional userspace stats reportng to zswap

 - "arch, mm: consolidate empty_zero_page" (Mike Rapoport)

   Some cleanups for our handling of ZERO_PAGE() and zero_pfn

 - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu
   Han)

   A robustness improvement and some cleanups in the kmemleak code

 - "Improve khugepaged scan logic" (Vernon Yang)

   Improve khugepaged scan logic and reduce CPU consumption by
   prioritizing scanning tasks that access memory frequently

 - "Make KHO Stateless" (Jason Miu)

   Simplify Kexec Handover by transitioning KHO from an xarray-based
   metadata tracking system with serialization to a radix tree data
   structure that can be passed directly to the next kernel

 - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas
   Ballasi and Steven Rostedt)

   Enhance vmscan's tracepointing

 - "mm: arch/shstk: Common shadow stack mapping helper and
   VM_NOHUGEPAGE" (Catalin Marinas)

   Cleanup for the shadow stack code: remove per-arch code in favour of
   a generic implementation

 - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin)

   Fix a WARN() which can be emitted the KHO restores a vmalloc area

 - "mm: Remove stray references to pagevec" (Tal Zussman)

   Several cleanups, mainly udpating references to "struct pagevec",
   which became folio_batch three years ago

 - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl
   Shutsemau)

   Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail
   pages encode their relationship to the head page

 - "mm/damon/core: improve DAMOS quota efficiency for core layer
   filters" (SeongJae Park)

   Improve two problematic behaviors of DAMOS that makes it less
   efficient when core layer filters are used

 - "mm/damon: strictly respect min_nr_regions" (SeongJae Park)

   Improve DAMON usability by extending the treatment of the
   min_nr_regions user-settable parameter

 - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka)

   The proper fix for a previously hotfixed SMP=n issue. Code
   simplifications and cleanups ensued

 - "mm: cleanups around unmapping / zapping" (David Hildenbrand)

   A bunch of cleanups around unmapping and zapping. Mostly
   simplifications, code movements, documentation and renaming of
   zapping functions

 - "support batched checking of the young flag for MGLRU" (Baolin Wang)

   Batched checking of the young flag for MGLRU. It's part cleanups; one
   benchmark shows large performance benefits for arm64

 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner)

   memcg cleanup and robustness improvements

 - "Allow order zero pages in page reporting" (Yuvraj Sakshith)

   Enhance free page reporting - it is presently and undesirably order-0
   pages when reporting free memory.

 - "mm: vma flag tweaks" (Lorenzo Stoakes)

   Cleanup work following from the recent conversion of the VMA flags to
   a bitmap

 - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae
   Park)

   Add some more developer-facing debug checks into DAMON core

 - "mm/damon: test and document power-of-2 min_region_sz requirement"
   (SeongJae Park)

   An additional DAMON kunit test and makes some adjustments to the
   addr_unit parameter handling

 - "mm/damon/core: make passed_sample_intervals comparisons
   overflow-safe" (SeongJae Park)

   Fix a hard-to-hit time overflow issue in DAMON core

 - "mm/damon: improve/fixup/update ratio calculation, test and
   documentation" (SeongJae Park)

   A batch of misc/minor improvements and fixups for DAMON

 - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David
   Hildenbrand)

   Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code
   movement was required.

 - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky)

   A somewhat random mix of fixups, recompression cleanups and
   improvements in the zram code

 - "mm/damon: support multiple goal-based quota tuning algorithms"
   (SeongJae Park)

   Extend DAMOS quotas goal auto-tuning to support multiple tuning
   algorithms that users can select

 - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao)

   Fix the khugpaged sysfs handling so we no longer spam the logs with
   reams of junk when starting/stopping khugepaged

 - "mm: improve map count checks" (Lorenzo Stoakes)

   Provide some cleanups and slight fixes in the mremap, mmap and vma
   code

 - "mm/damon: support addr_unit on default monitoring targets for
   modules" (SeongJae Park)

   Extend the use of DAMON core's addr_unit tunable

 - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache)

   Cleanups to khugepaged and is a base for Nico's planned khugepaged
   mTHP support

 - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand)

   Code movement and cleanups in the memhotplug and sparsemem code

 - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup
   CONFIG_MIGRATION" (David Hildenbrand)

   Rationalize some memhotplug Kconfig support

 - "change young flag check functions to return bool" (Baolin Wang)

   Cleanups to change all young flag check functions to return bool

 - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh
   Law and SeongJae Park)

   Fix a few potential DAMON bugs

 - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo
   Stoakes)

   Convert a lot of the existing use of the legacy vm_flags_t data type
   to the new vma_flags_t type which replaces it. Mainly in the vma
   code.

 - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes)

   Expand the mmap_prepare functionality, which is intended to replace
   the deprecated f_op->mmap hook which has been the source of bugs and
   security issues for some time. Cleanups, documentation, extension of
   mmap_prepare into filesystem drivers

 - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes)

   Simplify and clean up zap_huge_pmd(). Additional cleanups around
   vm_normal_folio_pmd() and the softleaf functionality are performed.

* tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm: fix deferred split queue races during migration
  mm/khugepaged: fix issue with tracking lock
  mm/huge_memory: add and use has_deposited_pgtable()
  mm/huge_memory: add and use normal_or_softleaf_folio_pmd()
  mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio()
  mm/huge_memory: separate out the folio part of zap_huge_pmd()
  mm/huge_memory: use mm instead of tlb->mm
  mm/huge_memory: remove unnecessary sanity checks
  mm/huge_memory: deduplicate zap deposited table call
  mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE()
  mm/huge_memory: add a common exit path to zap_huge_pmd()
  mm/huge_memory: handle buggy PMD entry in zap_huge_pmd()
  mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc
  mm/huge: avoid big else branch in zap_huge_pmd()
  mm/huge_memory: simplify vma_is_specal_huge()
  mm: on remap assert that input range within the proposed VMA
  mm: add mmap_action_map_kernel_pages[_full]()
  uio: replace deprecated mmap hook with mmap_prepare in uio_info
  drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare
  mm: allow handling of stacked mmap_prepare hooks in more drivers
  ...
2026-04-15 12:59:16 -07:00
Linus Torvalds
508fed6795 Merge tag 'ras_core_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Borislav Petkov:

 - Add new AMD MCA bank names and types to the MCA code, preceded by a
   clean up of the relevant places to have them more developer-friendly
   (read: sort them alphanumerically and clean up comments) such that
   adding new banks is easy

* tag 'ras_core_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce, EDAC/mce_amd: Add new SMCA bank types
  x86/mce, EDAC/mce_amd: Update CS bank type naming
  x86/mce, EDAC/mce_amd: Reorder SMCA bank type enums
2026-04-14 15:32:39 -07:00
Linus Torvalds
970216e023 Merge tag 'x86_misc_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Borislav Petkov:

 - Reference the tip tree maintainer handbook directly from the relevant
   MAINTAINERS file entries (covering timers, IRQ, locking, scheduling,
   perf, x86, and others) so that contributors and tooling can know
   where to look

 - Enable interrupt remapping in defconfig, which is an architectural
   requirement for x2APIC to function correctly on bare metal. Without
   it, x2APIC was effectively enabled but non-functional.

 - Ensure that drivers which register custom restart handlers (such as
   those needed for SoC-based x86 devices like Intel Lightning Mountain)
   are actually invoked during reboot, bringing x86 in line with how
   other architectures handle this.

 - Cleanups

* tag 'x86_misc_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Add references to tip tree handbook
  x86/64/defconfig: Add CONFIG_IRQ_REMAP
  x86/reboot: Execute the kernel restart handler upon machine restart
  x86/mtrr: Use kstrtoul() in parse_mtrr_spare_reg()
2026-04-14 15:15:08 -07:00
Linus Torvalds
cd4cdc53cc Merge tag 'x86_microcode_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode loading updates from Borislav Petkov:
 "The kernel carries a table of Intel CPUs family, model, stepping, etc
  tuples which say what is the latest microcode for that particular CPU.

  Some CPU variants differ only by the platform ID which determines what
  microcode needs to be loaded on them.

  Carve out the platform ID handling from the microcode loader and make it
  available in a more generic place so that the old microcode
  verification machinery can use it"

* tag 'x86_microcode_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode: Add platform mask to Intel microcode "old" list
  x86/cpu: Add platform ID to CPU matching structure
  x86/cpu: Add platform ID to CPU info structure
  x86/microcode: Refactor platform ID enumeration into a helper
2026-04-14 14:57:29 -07:00
Linus Torvalds
e9635f2a73 Merge tag 'x86_fred_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 FRED updates from Borislav Petkov:
 "We made the FRED support an opt-in initially out of fear of it
  breaking machines left and right in the case of a hw bug in the first
  generation of machines supporting it.

  Now that that the FRED code has seen a lot of hammering, flip the
  logic to be opt-out as is the usual case with new hw features"

* tag 'x86_fred_for_v7.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fred: Remove kernel log message when initializing exceptions
  x86/fred: Enable FRED by default
2026-04-14 14:50:51 -07:00
Linus Torvalds
9f2bb6c7b3 Merge tag 'x86_cpu_for_7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu updates from Dave Hansen:

 - Complete LASS enabling: deal with vsyscall and EFI

   The existing Linear Address Space Separation (LASS) support punted
   on support for common EFI and vsyscall configs. Complete the
   implementation by supporting EFI and vsyscall=xonly.

 - Clean up CPUID usage in newer Intel "avs" audio driver and update the
   x86-cpuid-db file

* tag 'x86_cpu_for_7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/x86/kcpuid: Update bitfields to x86-cpuid-db v3.0
  ASoC: Intel: avs: Include CPUID header at file scope
  ASoC: Intel: avs: Check maximum valid CPUID leaf
  x86/cpu: Remove LASS restriction on vsyscall emulation
  x86/vsyscall: Disable LASS if vsyscall mode is set to EMULATE
  x86/vsyscall: Restore vsyscall=xonly mode under LASS
  x86/traps: Consolidate user fixups in the #GP handler
  x86/vsyscall: Reorganize the page fault emulation code
  x86/cpu: Remove LASS restriction on EFI
  x86/efi: Disable LASS while executing runtime services
  x86/cpu: Defer LASS enabling until userspace comes up
2026-04-14 14:24:45 -07:00
Linus Torvalds
0972ba5605 Merge tag 'x86-platform-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 platform updates from Ingo Molnar:

 - Remove M486/M486SX/ELAN support, first minimal step (Ingo Molnar)

 - Print AGESA string from DMI additional information entry (Yazen
   Ghannam, Mario Limonciello)

 - Improve and fix the DMI code (Mario Limonciello):
     - Correct an indexing error in <linux/dmi.h>
     - Adjust dmi_decode() to use enums <linux/dmi.h>
     - Add pr_fmt() for dmi_scan.c to fix & standardize the log prefixes

* tag 'x86-platform-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: Print AGESA string from DMI additional information entry
  firmware: dmi: Add pr_fmt() for dmi_scan.c
  firmware: dmi: Adjust dmi_decode() to use enums
  firmware: dmi: Correct an indexing error in dmi.h
  x86/cpu: Remove M486/M486SX/ELAN support
2026-04-14 14:10:44 -07:00