Commit Graph

44753 Commits

Author SHA1 Message Date
Linus Torvalds
e56b2b6057 Fix preemption delays in the SGX code, remove unnecessarily UAPI-exported code,
fix a ld.lld linker (in)compatibility quirk and make the x86 SMP init code a bit
 more conservative to fix kexec() lockups.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmT97boRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1jObA//X7nug+d+IMLIs+c4579z4ZhkltMRxJVI
 Btf8sdHpwgTUtKaOLmJnGiJ7f0GK5NtoaNtGUJF28aQETVOhco0Fvg/R8k1FE2Tc
 CJqw6oy2FjVqD9qzZPCXh6QCvTtGjN5GF+xmoUbf7eZ9U8IVvOxBG+7yDMorQw3P
 zzjIccLLg/aDvNLN/yZD2oqw6UGHZuh/Qr/0Q4PkZ7zL+yWV8EC+HOx3rlQklq0x
 hh6YMwa4LGr3przUObHsfNS11EDzLDhg2WtTQMr12vlnpUB2eXnXWLklr6rpWjcz
 qJiMxkrEkygB7seXnuQ0b4KHN/17zdkJ+t6vZoznUTXs1ohIDLWdiNTSl03qCs9B
 V98a1x3MPT6aro9O/5ywyAJwPb0hvsg2S0ODFWab0Z3oRUbIG/k6dTEYlP7qZw8v
 EFMtLy6M2EILXetj8q2ZGcA0rKz7pj/z9SosWDzqNj76w7xGwDKrSWoKJckkCwG+
 j+ycBuKfrpxVYOF4ywvONSf35QTIW8BR0sM9Lg1GZuwaeincFwLf0cmS4ljGRyZ1
 Vsi0SfpIgVQkeY/17onTa1C5X6c2wIE9nq253M58Xnc9B2EWpYImr+4PVZk6s4GI
 GExvdPC/rIIwYa0LmvYTTlpHEd7f5qIAhfcEtMAuGSjVDLvmdDGFkaU7TgJ6Jcw2
 D12wKSAAgPU=
 =S38E
 -----END PGP SIGNATURE-----

Merge tag 'x86-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Fix preemption delays in the SGX code, remove unnecessarily
  UAPI-exported code, fix a ld.lld linker (in)compatibility quirk and
  make the x86 SMP init code a bit more conservative to fix kexec()
  lockups"

* tag 'x86-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Break up long non-preemptible delays in sgx_vepc_release()
  x86: Remove the arch_calc_vm_prot_bits() macro from the UAPI
  x86/build: Fix linker fill bytes quirk/incompatibility for ld.lld
  x86/smp: Don't send INIT to non-present and non-booted CPUs
2023-09-10 10:39:31 -07:00
Linus Torvalds
e79dbf03d8 Work around a firmware bug in the uncore PMU driver,
affecting certain Intel systems.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmT97GIRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1iLjRAAjk67cOUubVYXYOwlI4/5c+XiMC1qcqv9
 M0uK30h+EECqWdm5Waj4mjFJ3seWUPrNsmdY9L4a6Gd1+s6W10wIabCEJnDBcfj5
 M4Nv7OBnbfKb2JGfUfgd0OSSoclxL/QJh5UXMI+vLPKS2hMC5wL3BdKsxwrmbT+y
 ZwilRbkHU0kSZpkkKE9yZNOcHhBMZ6LuQGlCAQ5k99Q8Z2KbxPa8T/8zx/RjYfuw
 5WrE2gJJPXE/J/IHIvg7auhu2IcpzOmWPtb9J8MPExrUZLSQIYNhdqqyY9lvagKu
 OdYcotBEoZM2+MSXzVWSQPKVVKox03FDErwdGef/QLFmzzldFFGUjKSRBfpnMK9Q
 esjSiIGXlxh8fFcyCS/6FH48zA5y4BnBSzmPn3xt63VK0+EHPtUOUt8Xiug8DEYs
 O8hW+3SYmhr6seF9ioX0RCoqft8dQuNz07zZWfLu5Qc0Bl8aLBhwRoXsYKnKqems
 uqQ7bOb1FFwrS6AgebDhqHJUiw6WaeldsEolDyZzbKGJqFHJuTTFaECHApceLD7M
 V4ymgy6QoKeccctr8qnwzX/5xbwTx8fRfTIuL9ZR2KC0NJLF/UwIw+bEAq2vuv3A
 ROFYH+z1h4IvlCE3o3mRhGGYTxkdFw+BRXrWP690qxyRHBoHE+JwccSu36CKwBYS
 LiZn7CWuFtg=
 =Zq1S
 -----END PGP SIGNATURE-----

Merge tag 'perf-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf event fix from Ingo Molnar:
 "Work around a firmware bug in the uncore PMU driver, affecting certain
  Intel systems"

* tag 'perf-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore: Correct the number of CHAs on EMR
2023-09-10 10:34:46 -07:00
Linus Torvalds
0c02183427 ARM:
* Clean up vCPU targets, always returning generic v8 as the preferred target
 
 * Trap forwarding infrastructure for nested virtualization (used for traps
   that are taken from an L2 guest and are needed by the L1 hypervisor)
 
 * FEAT_TLBIRANGE support to only invalidate specific ranges of addresses
   when collapsing a table PTE to a block PTE.  This avoids that the guest
   refills the TLBs again for addresses that aren't covered by the table PTE.
 
 * Fix vPMU issues related to handling of PMUver.
 
 * Don't unnecessary align non-stack allocations in the EL2 VA space
 
 * Drop HCR_VIRT_EXCP_MASK, which was never used...
 
 * Don't use smp_processor_id() in kvm_arch_vcpu_load(),
   but the cpu parameter instead
 
 * Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort()
 
 * Remove prototypes without implementations
 
 RISC-V:
 
 * Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for guest
 
 * Added ONE_REG interface for SATP mode
 
 * Added ONE_REG interface to enable/disable multiple ISA extensions
 
 * Improved error codes returned by ONE_REG interfaces
 
 * Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V
 
 * Added get-reg-list selftest for KVM RISC-V
 
 s390:
 
 * PV crypto passthrough enablement (Tony, Steffen, Viktor, Janosch)
   Allows a PV guest to use crypto cards. Card access is governed by
   the firmware and once a crypto queue is "bound" to a PV VM every
   other entity (PV or not) looses access until it is not bound
   anymore. Enablement is done via flags when creating the PV VM.
 
 * Guest debug fixes (Ilya)
 
 x86:
 
 * Clean up KVM's handling of Intel architectural events
 
 * Intel bugfixes
 
 * Add support for SEV-ES DebugSwap, allowing SEV-ES guests to use debug
   registers and generate/handle #DBs
 
 * Clean up LBR virtualization code
 
 * Fix a bug where KVM fails to set the target pCPU during an IRTE update
 
 * Fix fatal bugs in SEV-ES intrahost migration
 
 * Fix a bug where the recent (architecturally correct) change to reinject
   #BP and skip INT3 broke SEV guests (can't decode INT3 to skip it)
 
 * Retry APIC map recalculation if a vCPU is added/enabled
 
 * Overhaul emergency reboot code to bring SVM up to par with VMX, tie the
   "emergency disabling" behavior to KVM actually being loaded, and move all of
   the logic within KVM
 
 * Fix user triggerable WARNs in SVM where KVM incorrectly assumes the TSC
   ratio MSR cannot diverge from the default when TSC scaling is disabled
   up related code
 
 * Add a framework to allow "caching" feature flags so that KVM can check if
   the guest can use a feature without needing to search guest CPUID
 
 * Rip out the ancient MMU_DEBUG crud and replace the useful bits with
   CONFIG_KVM_PROVE_MMU
 
 * Fix KVM's handling of !visible guest roots to avoid premature triple fault
   injection
 
 * Overhaul KVM's page-track APIs, and KVMGT's usage, to reduce the API surface
   that is needed by external users (currently only KVMGT), and fix a variety
   of issues in the process
 
 This last item had a silly one-character bug in the topic branch that
 was sent to me.  Because it caused pretty bad selftest failures in
 some configurations, I decided to squash in the fix.  So, while the
 exact commit ids haven't been in linux-next, the code has (from the
 kvm-x86 tree).
 
 Generic:
 
 * Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier events to pass
   action specific data without needing to constantly update the main handlers.
 
 * Drop unused function declarations
 
 Selftests:
 
 * Add testcases to x86's sync_regs_test for detecting KVM TOCTOU bugs
 
 * Add support for printf() in guest code and covert all guest asserts to use
   printf-based reporting
 
 * Clean up the PMU event filter test and add new testcases
 
 * Include x86 selftests in the KVM x86 MAINTAINERS entry
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmT1m0kUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroMNgggAiN7nz6UC423FznuI+yO3TLm8tkx1
 CpKh5onqQogVtchH+vrngi97cfOzZb1/AtifY90OWQi31KEWhehkeofcx7G6ERhj
 5a9NFADY1xGBsX4exca/VHDxhnzsbDWaWYPXw5vWFWI6erft9Mvy3tp1LwTvOzqM
 v8X4aWz+g5bmo/DWJf4Wu32tEU6mnxzkrjKU14JmyqQTBawVmJ3RYvHVJ/Agpw+n
 hRtPAy7FU6XTdkmq/uCT+KUHuJEIK0E/l1js47HFAqSzwdW70UDg14GGo1o4ETxu
 RjZQmVNvL57yVgi6QU38/A0FWIsWQm5IlaX1Ug6x8pjZPnUKNbo9BY4T1g==
 =W+4p
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Clean up vCPU targets, always returning generic v8 as the preferred
     target

   - Trap forwarding infrastructure for nested virtualization (used for
     traps that are taken from an L2 guest and are needed by the L1
     hypervisor)

   - FEAT_TLBIRANGE support to only invalidate specific ranges of
     addresses when collapsing a table PTE to a block PTE. This avoids
     that the guest refills the TLBs again for addresses that aren't
     covered by the table PTE.

   - Fix vPMU issues related to handling of PMUver.

   - Don't unnecessary align non-stack allocations in the EL2 VA space

   - Drop HCR_VIRT_EXCP_MASK, which was never used...

   - Don't use smp_processor_id() in kvm_arch_vcpu_load(), but the cpu
     parameter instead

   - Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort()

   - Remove prototypes without implementations

  RISC-V:

   - Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for guest

   - Added ONE_REG interface for SATP mode

   - Added ONE_REG interface to enable/disable multiple ISA extensions

   - Improved error codes returned by ONE_REG interfaces

   - Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V

   - Added get-reg-list selftest for KVM RISC-V

  s390:

   - PV crypto passthrough enablement (Tony, Steffen, Viktor, Janosch)

     Allows a PV guest to use crypto cards. Card access is governed by
     the firmware and once a crypto queue is "bound" to a PV VM every
     other entity (PV or not) looses access until it is not bound
     anymore. Enablement is done via flags when creating the PV VM.

   - Guest debug fixes (Ilya)

  x86:

   - Clean up KVM's handling of Intel architectural events

   - Intel bugfixes

   - Add support for SEV-ES DebugSwap, allowing SEV-ES guests to use
     debug registers and generate/handle #DBs

   - Clean up LBR virtualization code

   - Fix a bug where KVM fails to set the target pCPU during an IRTE
     update

   - Fix fatal bugs in SEV-ES intrahost migration

   - Fix a bug where the recent (architecturally correct) change to
     reinject #BP and skip INT3 broke SEV guests (can't decode INT3 to
     skip it)

   - Retry APIC map recalculation if a vCPU is added/enabled

   - Overhaul emergency reboot code to bring SVM up to par with VMX, tie
     the "emergency disabling" behavior to KVM actually being loaded,
     and move all of the logic within KVM

   - Fix user triggerable WARNs in SVM where KVM incorrectly assumes the
     TSC ratio MSR cannot diverge from the default when TSC scaling is
     disabled up related code

   - Add a framework to allow "caching" feature flags so that KVM can
     check if the guest can use a feature without needing to search
     guest CPUID

   - Rip out the ancient MMU_DEBUG crud and replace the useful bits with
     CONFIG_KVM_PROVE_MMU

   - Fix KVM's handling of !visible guest roots to avoid premature
     triple fault injection

   - Overhaul KVM's page-track APIs, and KVMGT's usage, to reduce the
     API surface that is needed by external users (currently only
     KVMGT), and fix a variety of issues in the process

  Generic:

   - Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier
     events to pass action specific data without needing to constantly
     update the main handlers.

   - Drop unused function declarations

  Selftests:

   - Add testcases to x86's sync_regs_test for detecting KVM TOCTOU bugs

   - Add support for printf() in guest code and covert all guest asserts
     to use printf-based reporting

   - Clean up the PMU event filter test and add new testcases

   - Include x86 selftests in the KVM x86 MAINTAINERS entry"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (279 commits)
  KVM: x86/mmu: Include mmu.h in spte.h
  KVM: x86/mmu: Use dummy root, backed by zero page, for !visible guest roots
  KVM: x86/mmu: Disallow guest from using !visible slots for page tables
  KVM: x86/mmu: Harden TDP MMU iteration against root w/o shadow page
  KVM: x86/mmu: Harden new PGD against roots without shadow pages
  KVM: x86/mmu: Add helper to convert root hpa to shadow page
  drm/i915/gvt: Drop final dependencies on KVM internal details
  KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers
  KVM: x86/mmu: Drop @slot param from exported/external page-track APIs
  KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled
  KVM: x86/mmu: Assert that correct locks are held for page write-tracking
  KVM: x86/mmu: Rename page-track APIs to reflect the new reality
  KVM: x86/mmu: Drop infrastructure for multiple page-track modes
  KVM: x86/mmu: Use page-track notifiers iff there are external users
  KVM: x86/mmu: Move KVM-only page-track declarations to internal header
  KVM: x86: Remove the unused page-track hook track_flush_slot()
  drm/i915/gvt: switch from ->track_flush_slot() to ->track_remove_region()
  KVM: x86: Add a new page-track hook to handle memslot deletion
  drm/i915/gvt: Don't bother removing write-protection on to-be-deleted slot
  KVM: x86: Reject memslot MOVE operations if KVMGT is attached
  ...
2023-09-07 13:52:20 -07:00
Jack Wang
3d7d72a34e x86/sgx: Break up long non-preemptible delays in sgx_vepc_release()
On large enclaves we hit the softlockup warning with following call trace:

	xa_erase()
	sgx_vepc_release()
	__fput()
	task_work_run()
	do_exit()

The latency issue is similar to the one fixed in:

  8795359e35 ("x86/sgx: Silence softlockup detection when releasing large enclaves")

The test system has 64GB of enclave memory, and all is assigned to a single VM.
Release of 'vepc' takes a longer time and causes long latencies, which triggers
the softlockup warning.

Add cond_resched() to give other tasks a chance to run and reduce
latencies, which also avoids the softlockup detector.

[ mingo: Rewrote the changelog. ]

Fixes: 540745ddbc ("x86/sgx: Introduce virtual EPC for use by KVM guests")
Reported-by: Yu Zhang <yu.zhang@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Yu Zhang <yu.zhang@ionos.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Acked-by: Haitao Huang <haitao.huang@linux.intel.com>
Cc: stable@vger.kernel.org
2023-09-06 23:55:09 +02:00
Thomas Huth
659df86a7b x86: Remove the arch_calc_vm_prot_bits() macro from the UAPI
The arch_calc_vm_prot_bits() macro uses VM_PKEY_BIT0 etc. which are
not part of the UAPI, so the macro is completely useless for userspace.

It is also hidden behind the CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
config switch which we shouldn't expose to userspace. Thus let's move
this macro into a new internal header instead.

Fixes: 8f62c88322 ("x86/mm/pkeys: Add arch-specific VMA protection bits")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lore.kernel.org/r/20230906162658.142511-1-thuth@redhat.com
2023-09-06 23:50:46 +02:00
Song Liu
65e710899f x86/build: Fix linker fill bytes quirk/incompatibility for ld.lld
With ":text =0xcccc", ld.lld fills unused text area with 0xcccc0000.
Example objdump -D output:

	ffffffff82b04203:       00 00                   add    %al,(%rax)
	ffffffff82b04205:       cc                      int3
	ffffffff82b04206:       cc                      int3
	ffffffff82b04207:       00 00                   add    %al,(%rax)
	ffffffff82b04209:       cc                      int3
	ffffffff82b0420a:       cc                      int3

Replace it with ":text =0xcccccccc", so we get the following instead:

	ffffffff82b04203:       cc                      int3
	ffffffff82b04204:       cc                      int3
	ffffffff82b04205:       cc                      int3
	ffffffff82b04206:       cc                      int3
	ffffffff82b04207:       cc                      int3
	ffffffff82b04208:       cc                      int3

gcc/ld doesn't seem to have the same issue. The generated code stays the
same for gcc/ld.

Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Fixes: 7705dc8557 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes")
Link: https://lore.kernel.org/r/20230906175215.2236033-1-song@kernel.org
2023-09-06 23:49:12 +02:00
Kan Liang
6f7f984fa8 perf/x86/uncore: Correct the number of CHAs on EMR
Starting from SPR, the basic uncore PMON information is retrieved from
the discovery table (resides in an MMIO space populated by BIOS). It is
called the discovery method. The existing value of the type->num_boxes
is from the discovery table.

On some SPR variants, there is a firmware bug that makes the value from the
discovery table incorrect. We use the value from the
SPR_MSR_UNC_CBO_CONFIG MSR to replace the one from the discovery table:

   38776cc45e ("perf/x86/uncore: Correct the number of CHAs on SPR")

Unfortunately, the SPR_MSR_UNC_CBO_CONFIG isn't available for the EMR
XCC (Always returns 0), but the above firmware bug doesn't impact the
EMR XCC.

Don't let the value from the MSR replace the existing value from the
discovery table.

Fixes: 38776cc45e ("perf/x86/uncore: Correct the number of CHAs on SPR")
Reported-by: Stephane Eranian <eranian@google.com>
Reported-by: Yunying Sun <yunying.sun@intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Yunying Sun <yunying.sun@intel.com>
Link: https://lore.kernel.org/r/20230905134248.496114-1-kan.liang@linux.intel.com
2023-09-05 21:50:21 +02:00
Linus Torvalds
61401a8724 Kbuild updates for v6.6
- Enable -Wenum-conversion warning option
 
  - Refactor the rpm-pkg target
 
  - Fix scripts/setlocalversion to consider annotated tags for rt-kernel
 
  - Add a jump key feature for the search menu of 'make nconfig'
 
  - Support Qt6 for 'make xconfig'
 
  - Enable -Wformat-overflow, -Wformat-truncation, -Wstringop-overflow, and
    -Wrestrict warnings for W=1 builds
 
  - Replace <asm/export.h> with <linux/export.h> for alpha, ia64, and sparc
 
  - Support DEB_BUILD_OPTIONS=parallel=N for the debian source package
 
  - Refactor scripts/Makefile.modinst and fix some modules_sign issues
 
  - Add a new Kconfig env variable to warn symbols that are not defined anywhere
 
  - Show help messages of config fragments in 'make help'
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmT3X/oVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsG58oQAIXDrka3r53Flky/uJjSl8ab620o
 XL3u4PF/ekv6qsZoLlU24WQP8BzcJO6gPHFz88mE9/J1+wHpNKZLZehjpgj1cCY3
 LatbEAa3DCZPC/c7P/nz+FT4mjTZpKOeQmvZVfA+xonBHmTyVUKgws0uDB/xuTjE
 GARyOX7ymD0AAZv84SUUCiaBe5Y2Bkrki67HfteS4bxW8GHg0rZWzrFUUkEkoG54
 elNOYR0WYROwyo8Iokd2MedVdK2SPZxvY8i67hXl2K+Qve6tLNk8dbRIENnYI0pk
 7oQVmIfC20eu9CteywHlyjt8jpTOeIrRc2yhJKR0YrjjIzKhulRGMh+pFAAwoySd
 Se60uWCS2AydcXWTrtb+iwFUyM2zRK4SaMlxleqnoE/bWYp6jhg9qbV9xpztWSYI
 j39k9aX7B19stN1drzJeyXdILRVtaAQCcax3RR+mGgm4Z5fuTDntPepvIv8J3lBg
 QZ4MCdOdtFw33eQaKa7O3LddD3q1X355xeaIITivEe3rAk5iIJYu3Ty1VY+/XTcH
 ktSVl83zQ5Ge3tvx8D6kCR9J8jAQyTLIKHxvr/j969HgZKguS2i37eChnPyKcu23
 ZMKJcmCJ1O7naQXVrb/TeiaMR0UEo/PSdrUjpEO3LlMpRthNXLVSLfgJGv8WLO7/
 pb/HFXHgKaSORiRV
 =lfUi
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Enable -Wenum-conversion warning option

 - Refactor the rpm-pkg target

 - Fix scripts/setlocalversion to consider annotated tags for rt-kernel

 - Add a jump key feature for the search menu of 'make nconfig'

 - Support Qt6 for 'make xconfig'

 - Enable -Wformat-overflow, -Wformat-truncation, -Wstringop-overflow,
   and -Wrestrict warnings for W=1 builds

 - Replace <asm/export.h> with <linux/export.h> for alpha, ia64, and
   sparc

 - Support DEB_BUILD_OPTIONS=parallel=N for the debian source package

 - Refactor scripts/Makefile.modinst and fix some modules_sign issues

 - Add a new Kconfig env variable to warn symbols that are not defined
   anywhere

 - Show help messages of config fragments in 'make help'

* tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (62 commits)
  kconfig: fix possible buffer overflow
  kbuild: Show marked Kconfig fragments in "help"
  kconfig: add warn-unknown-symbols sanity check
  kbuild: dummy-tools: make MPROFILE_KERNEL checks work on BE
  Documentation/llvm: refresh docs
  modpost: Skip .llvm.call-graph-profile section check
  kbuild: support modules_sign for external modules as well
  kbuild: support 'make modules_sign' with CONFIG_MODULE_SIG_ALL=n
  kbuild: move more module installation code to scripts/Makefile.modinst
  kbuild: reduce the number of mkdir calls during modules_install
  kbuild: remove $(MODLIB)/source symlink
  kbuild: move depmod rule to scripts/Makefile.modinst
  kbuild: add modules_sign to no-{compiler,sync-config}-targets
  kbuild: do not run depmod for 'make modules_sign'
  kbuild: deb-pkg: support DEB_BUILD_OPTIONS=parallel=N in debian/rules
  alpha: remove <asm/export.h>
  alpha: replace #include <asm/export.h> with #include <linux/export.h>
  ia64: remove <asm/export.h>
  ia64: replace #include <asm/export.h> with #include <linux/export.h>
  sparc: remove <asm/export.h>
  ...
2023-09-05 11:01:47 -07:00
Linus Torvalds
68d76d4e7e This pull request contains the following changes for UML:
- Drop 32-bit checksum implementation and re-use it from arch/x86
 - String function cleanup
 - Fixes for -Wmissing-variable-declarations and -Wmissing-prototypes builds
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCAA0FiEEdgfidid8lnn52cLTZvlZhesYu8EFAmT0158WHHJpY2hhcmRA
 c2lnbWEtc3Rhci5hdAAKCRBm+VmF6xi7wTUvD/4yx5F1tFljUrsBipHtg8NX81Wk
 /yqidBnug71S76BhkoOHX1P+qxzl3WS+zp35zclL2/kPPew1vc5TpVXXFdZa5Xkh
 yaEPGSNKY+yFnaxYWrg/fWYYJbBS+HLDB+Am3fyYdeiXmAEV9K/5HVptZOnDqXnM
 0hJf8hKzkfmn0eaXBlvyfZaQSVofK3R9lKalDXMOwc0vp7i1gEHWuN3K1jjM6WCx
 /lPkpHKErRCDGyCtr/dY9J0FgCROo5ytSQq7KIBat+F+JBGZh7pcruEbl11fg1Ed
 w4RjbcwYITBNHOlrb2kYvxIu7/clxgzYWtcarS0GB3o7Iu8ZQXijWKXakeRV2DBx
 by6NAxliZZDp+QmRpPMDgZPPbN5BQY3GDCYY8eAQEAllrTZXE0ZJyIgBPYX6j4bF
 pOKAHd/hErpoPXi5Ec7r01+pE9aMOZUEK7ebXSM7Hqnj4btcX+1b5V3FMrAHPqEa
 LZpQmeJRtIJQZNRhjjgQx0zd2oJ2OXz0gc+Dap2fj1aSIfGkwIIo0hXvNSoETH3J
 Swsr4v+FynCGCWyNsYFEmWMEe9EWOrElvSNk+Hek4gdQc9lByo9JXxSfOxcoaYLG
 vebV5kog6NDP3DgmnfmPzAnGjpGwMhjNrMQ9UR1Ul3BUOyvZ4nljdzr4tNYVnF0R
 ydtiEOf5IjHW2Jq2Ww==
 =UmrW
 -----END PGP SIGNATURE-----

Merge tag 'uml-for-linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

Pull UML updates from Richard Weinberger:

 - Drop 32-bit checksum implementation and re-use it from arch/x86

 - String function cleanup

 - Fixes for -Wmissing-variable-declarations and -Wmissing-prototypes
   builds

* tag 'uml-for-linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux:
  um: virt-pci: fix missing declaration warning
  um: Refactor deprecated strncpy to memcpy
  um: fix 3 instances of -Wmissing-prototypes
  um: port_kern: fix -Wmissing-variable-declarations
  uml: audio: fix -Wmissing-variable-declarations
  um: vector: refactor deprecated strncpy
  um: use obj-y to descend into arch/um/*/
  um: Hard-code the result of 'uname -s'
  um: Use the x86 checksum implementation on 32-bit
  asm-generic: current: Don't include thread-info.h if building asm
  um: Remove unsued extern declaration ldt_host_info()
  um: Fix hostaudio build errors
  um: Remove strlcpy usage
2023-09-04 11:32:21 -07:00
Linus Torvalds
0b90c5637d hyperv-next for v6.6
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCgAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAmT0EE8THHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXg5FCACGJ6n2ikhtRHAENHIVY/mTh+HbhO07
 ERzjADfqKF43u1Nt9cslgT4MioqwLjQsAu/A0YcJgVxVSOtg7dnbDmurRAjrGT/3
 iKqcVvnaiwSV44TkF8evpeMttZSOg29ImmpyQjoZJJvDMfpxleEK53nuKB9EsjKL
 Mz/0gSPoNc79bWF+85cVhgPnGIh9nBarxHqVsuWjMhc+UFhzjf9mOtk34qqPfJ1Q
 4RsKGEjkVkeXoG6nGd6Gl/+8WoTpenOZQLchhInocY+k9FlAzW1Kr+ICLDx+Topw
 8OJ6fv2rMDOejT9aOaA3/imf7LMer0xSUKb6N0sqQAQX8KzwcOYyKtQJ
 =rC/v
 -----END PGP SIGNATURE-----

Merge tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Support for SEV-SNP guests on Hyper-V (Tianyu Lan)

 - Support for TDX guests on Hyper-V (Dexuan Cui)

 - Use SBRM API in Hyper-V balloon driver (Mitchell Levy)

 - Avoid dereferencing ACPI root object handle in VMBus driver (Maciej
   Szmigiero)

 - A few misecllaneous fixes (Jiapeng Chong, Nathan Chancellor, Saurabh
   Sengar)

* tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits)
  x86/hyperv: Remove duplicate include
  x86/hyperv: Move the code in ivm.c around to avoid unnecessary ifdef's
  x86/hyperv: Remove hv_isolation_type_en_snp
  x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the paravisor
  Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor
  x86/hyperv: Introduce a global variable hyperv_paravisor_present
  Drivers: hv: vmbus: Support >64 VPs for a fully enlightened TDX/SNP VM
  x86/hyperv: Fix serial console interrupts for fully enlightened TDX guests
  Drivers: hv: vmbus: Support fully enlightened TDX guests
  x86/hyperv: Support hypercalls for fully enlightened TDX guests
  x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guests
  x86/hyperv: Fix undefined reference to isolation_type_en_snp without CONFIG_HYPERV
  x86/hyperv: Add missing 'inline' to hv_snp_boot_ap() stub
  hv: hyperv.h: Replace one-element array with flexible-array member
  Drivers: hv: vmbus: Don't dereference ACPI root object handle
  x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES
  x86/hyperv: Add smp support for SEV-SNP guest
  clocksource: hyper-v: Mark hyperv tsc page unencrypted in sev-snp enlightened guest
  x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp enlightened guest
  drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP enlightened guest
  ...
2023-09-04 11:26:29 -07:00
Thomas Gleixner
3f874c9b2a x86/smp: Don't send INIT to non-present and non-booted CPUs
Vasant reported that kexec() can hang or reset the machine when it tries to
park CPUs via INIT. This happens when the kernel is using extended APIC,
but the present mask has APIC IDs >= 0x100 enumerated.

As extended APIC can only handle 8 bit of APIC ID sending INIT to APIC ID
0x100 sends INIT to APIC ID 0x0. That's the boot CPU which is special on
x86 and INIT causes the system to hang or resets the machine.

Prevent this by sending INIT only to those CPUs which have been booted
once.

Fixes: 45e34c8af5 ("x86/smp: Put CPUs into INIT on shutdown if possible")
Reported-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/87cyzwjbff.ffs@tglx
2023-09-04 15:41:42 +02:00
Kees Cook
feec5e1f74 kbuild: Show marked Kconfig fragments in "help"
Currently the Kconfig fragments in kernel/configs and arch/*/configs
that aren't used internally aren't discoverable through "make help",
which consists of hard-coded lists of config fragments. Instead, list
all the fragment targets that have a "# Help: " comment prefix so the
targets can be generated dynamically.

Add logic to the Makefile to search for and display the fragment and
comment. Add comments to fragments that are intended to be direct targets.

Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-09-04 02:04:20 +09:00
Linus Torvalds
2fcbb03847 * Mark all Skylake CPUs as vulnerable to GDS
* Fix PKRU covert channel
  * Fix -Wmissing-variable-declarations warning for ia32_xyz_class
  * Fix kernel-doc annotation warning
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmTyK2sACgkQaDWVMHDJ
 krCPyA//WbT65hhGZt5UHayoW3Cv8NmS4kRf6FTVMmt1yIvbOtVmWVZeOGMypprC
 jYBPOdTf1SdoUxeD1cTTd/rtbYknczaBLC5VGilGb2/663yQl9ThT3ePc6OgUpPW
 28ItLslfHGchHbrOgCgUK8Aiv8xRdfNUJoByMTOoce6eGUQsgYaNOq74z1YaLsZ4
 afbitcd/vWO9eJfW5DNl26rIP+ksOgA/Iue8uRiEczoPltnbUxGGLCtuuR9B2Xxi
 FqfttvcnUy9yFJBnELx4721VtTcmK4Dq5O/ZoJnmVQqRPY9aXpkbwZnH9co8r/uh
 GueQj30l6VhEO6XnwPvjsOghXI2vOMrxlL3zGMw5y6pjfUWa4W6f33EV6mByYfml
 dfPTXIz9K1QxznHtk6xVhn1X8CFw7L1L7CC/2CPQPETiuqyjWrHqvFBXcsWpKq4N
 1GjnpoveNZmWcE7UY9qEHAXGh7ndI+EIux/0WfJJHOE/fzCr06GphQdxNwPGdi5O
 T3JkZf6R4GBvfi6e0F6Qn2B02sDl18remmAMi9bAn/M31g+mvAoHqKLlI9EzAGGz
 91PzJdHecdvalU6zsCKqi0ETzq11WG7zCfSXs+jeHBe1jsUITpcZCkpVi2pGA2aq
 X7qLjJyW+Sx0hdE2IWFhCOfiwGFpXxfegCl1uax3HrZg6rrORbw=
 =prt2
 -----END PGP SIGNATURE-----

Merge tag 'x86-urgent-2023-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Dave Hansen:
 "The most important fix here adds a missing CPU model to the recent
  Gather Data Sampling (GDS) mitigation list to ensure that mitigations
  are available on that CPU.

  There are also a pair of warning fixes, and closure of a covert
  channel that pops up when protection keys are disabled.

  Summary:
   - Mark all Skylake CPUs as vulnerable to GDS
   - Fix PKRU covert channel
   - Fix -Wmissing-variable-declarations warning for ia32_xyz_class
   - Fix kernel-doc annotation warning"

* tag 'x86-urgent-2023-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu/xstate: Fix PKRU covert channel
  x86/irq/i8259: Fix kernel-doc annotation warning
  x86/speculation: Mark all Skylake CPUs as vulnerable to GDS
  x86/audit: Fix -Wmissing-variable-declarations warning for ia32_xyz_class
2023-09-01 16:40:19 -07:00
Linus Torvalds
1c9f8dff62 Char/Misc driver changes for 6.6-rc1
Here is the big set of char/misc and other small driver subsystem
 changes for 6.6-rc1.
 
 Stuff all over the place here, lots of driver updates and changes and
 new additions.  Short summary is:
   - new IIO drivers and updates
   - Interconnect driver updates
   - fpga driver updates and additions
   - fsi driver updates
   - mei driver updates
   - coresight driver updates
   - nvmem driver updates
   - counter driver updates
   - lots of smaller misc and char driver updates and additions
 
 All of these have been in linux-next for a long time with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZPH64g8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ynr2QCfd3RKeR+WnGzyEOFhksl30UJJhiIAoNZtYT5+
 t9KG0iMDXRuTsOqeEQbd
 =tVnk
 -----END PGP SIGNATURE-----

Merge tag 'char-misc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big set of char/misc and other small driver subsystem
  changes for 6.6-rc1.

  Stuff all over the place here, lots of driver updates and changes and
  new additions. Short summary is:

   - new IIO drivers and updates

   - Interconnect driver updates

   - fpga driver updates and additions

   - fsi driver updates

   - mei driver updates

   - coresight driver updates

   - nvmem driver updates

   - counter driver updates

   - lots of smaller misc and char driver updates and additions

  All of these have been in linux-next for a long time with no reported
  problems"

* tag 'char-misc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (267 commits)
  nvmem: core: Notify when a new layout is registered
  nvmem: core: Do not open-code existing functions
  nvmem: core: Return NULL when no nvmem layout is found
  nvmem: core: Create all cells before adding the nvmem device
  nvmem: u-boot-env:: Replace zero-length array with DECLARE_FLEX_ARRAY() helper
  nvmem: sec-qfprom: Add Qualcomm secure QFPROM support
  dt-bindings: nvmem: sec-qfprom: Add bindings for secure qfprom
  dt-bindings: nvmem: Add compatible for QCM2290
  nvmem: Kconfig: Fix typo "drive" -> "driver"
  nvmem: Explicitly include correct DT includes
  nvmem: add new NXP QorIQ eFuse driver
  dt-bindings: nvmem: Add t1023-sfp efuse support
  dt-bindings: nvmem: qfprom: Add compatible for MSM8226
  nvmem: uniphier: Use devm_platform_get_and_ioremap_resource()
  nvmem: qfprom: do some cleanup
  nvmem: stm32-romem: Use devm_platform_get_and_ioremap_resource()
  nvmem: rockchip-efuse: Use devm_platform_get_and_ioremap_resource()
  nvmem: meson-mx-efuse: Convert to devm_platform_ioremap_resource()
  nvmem: lpc18xx_otp: Convert to devm_platform_ioremap_resource()
  nvmem: brcm_nvram: Use devm_platform_get_and_ioremap_resource()
  ...
2023-09-01 09:53:54 -07:00
Linus Torvalds
28a4f91f5f Driver core changes for 6.6-rc1
Here is a small set of driver core updates and additions for 6.6-rc1.
 
 Included in here are:
   - stable kernel documentation updates
   - class structure const work from Ivan on various subsystems
   - kernfs tweaks
   - driver core tests!
   - kobject sanity cleanups
   - kobject structure reordering to save space
   - driver core error code handling fixups
   - other minor driver core cleanups
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZPH77Q8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ylZMACePk8SitfaJc6FfFf5I7YK7Nq0V8MAn0nUjgsR
 i8NcNpu/Yv4HGrDgTdh/
 =PJbk
 -----END PGP SIGNATURE-----

Merge tag 'driver-core-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is a small set of driver core updates and additions for 6.6-rc1.

  Included in here are:

   - stable kernel documentation updates

   - class structure const work from Ivan on various subsystems

   - kernfs tweaks

   - driver core tests!

   - kobject sanity cleanups

   - kobject structure reordering to save space

   - driver core error code handling fixups

   - other minor driver core cleanups

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (32 commits)
  driver core: Call in reversed order in device_platform_notify_remove()
  driver core: Return proper error code when dev_set_name() fails
  kobject: Remove redundant checks for whether ktype is NULL
  kobject: Add sanity check for kset->kobj.ktype in kset_register()
  drivers: base: test: Add missing MODULE_* macros to root device tests
  drivers: base: test: Add missing MODULE_* macros for platform devices tests
  drivers: base: Free devm resources when unregistering a device
  drivers: base: Add basic devm tests for platform devices
  drivers: base: Add basic devm tests for root devices
  kernfs: fix missing kernfs_iattr_rwsem locking
  docs: stable-kernel-rules: mention that regressions must be prevented
  docs: stable-kernel-rules: fine-tune various details
  docs: stable-kernel-rules: make the examples for option 1 a proper list
  docs: stable-kernel-rules: move text around to improve flow
  docs: stable-kernel-rules: improve structure by changing headlines
  base/node: Remove duplicated include
  kernfs: attach uuid for every kernfs and report it in fsid
  kernfs: add stub helper for kernfs_generic_poll()
  x86/resctrl: make pseudo_lock_class a static const structure
  x86/MSR: make msr_class a static const structure
  ...
2023-09-01 09:43:18 -07:00
Jim Mattson
18032b47ad x86/fpu/xstate: Fix PKRU covert channel
When XCR0[9] is set, PKRU can be read and written from userspace with
XSAVE and XRSTOR, even when CR4.PKE is clear.

Clear XCR0[9] when protection keys are disabled.

Reported-by: Tavis Ormandy <taviso@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20230831043228.1194256-1-jmattson@google.com
2023-08-31 23:29:49 +02:00
Linus Torvalds
df57721f9a Add x86 shadow stack support
Convert IBT selftest to asm to fix objtool warning
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmTv1QQACgkQaDWVMHDJ
 krAUwhAAn6TOwHJK8BSkHeiQhON1nrlP3c5cv0AyZ2NP8RYDrZrSZvhpYBJ6wgKC
 Cx5CGq5nn9twYsYS3KsktLKDfR3lRdsQ7K9qtyFtYiaeaVKo+7gEKl/K+klwai8/
 gninQWHk0zmSCja8Vi77q52WOMkQKapT8+vaON9EVDO8dVEi+CvhAIfPwMafuiwO
 Rk4X86SzoZu9FP79LcCg9XyGC/XbM2OG9eNUTSCKT40qTTKm5y4gix687NvAlaHR
 ko5MTsdl0Wfp6Qk0ohT74LnoA2c1g/FluvZIM33ci/2rFpkf9Hw7ip3lUXqn6CPx
 rKiZ+pVRc0xikVWkraMfIGMJfUd2rhelp8OyoozD7DB7UZw40Q4RW4N5tgq9Fhe9
 MQs3p1v9N8xHdRKl365UcOczUxNAmv4u0nV5gY/4FMC6VjldCl2V9fmqYXyzFS4/
 Ogg4FSd7c2JyGFKPs+5uXyi+RY2qOX4+nzHOoKD7SY616IYqtgKoz5usxETLwZ6s
 VtJOmJL0h//z0A7tBliB0zd+SQ5UQQBDC2XouQH2fNX2isJMn0UDmWJGjaHgK6Hh
 8jVp6LNqf+CEQS387UxckOyj7fu438hDky1Ggaw4YqowEOhQeqLVO4++x+HITrbp
 AupXfbJw9h9cMN63Yc0gVxXQ9IMZ+M7UxLtZ3Cd8/PVztNy/clA=
 =3UUm
 -----END PGP SIGNATURE-----

Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...
2023-08-31 12:20:12 -07:00
Vincenzo Palazzo
d87e89c273 x86/irq/i8259: Fix kernel-doc annotation warning
Fix this warning:

  arch/x86/kernel/i8259.c:235: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
   * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
    CC      arch/x86/kernel/irqinit.o

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230830131211.88226-1-vincenzopalazzodev@gmail.com
2023-08-31 20:43:30 +02:00
Dave Hansen
c9f4c45c8e x86/speculation: Mark all Skylake CPUs as vulnerable to GDS
The Gather Data Sampling (GDS) vulnerability is common to all Skylake
processors.  However, the "client" Skylakes* are now in this list:

	https://www.intel.com/content/www/us/en/support/articles/000022396/processors.html

which means they are no longer included for new vulnerabilities here:

	https://www.intel.com/content/www/us/en/developer/topic-technology/software-security-guidance/processors-affected-consolidated-product-cpu-model.html

or in other GDS documentation.  Thus, they were not included in the
original GDS mitigation patches.

Mark SKYLAKE and SKYLAKE_L as vulnerable to GDS to match all the
other Skylake CPUs (which include Kaby Lake).  Also group the CPUs
so that the ones that share the exact same vulnerabilities are next
to each other.

Last, move SRBDS to the end of each line.  This makes it clear at a
glance that SKYLAKE_X is unique.  Of the five Skylakes, it is the
only "server" CPU and has a different implementation from the
clients of the "special register" hardware, making it immune to SRBDS.

This makes the diff much harder to read, but the resulting table is
worth it.

I very much appreciate the report from Michael Zhivich about this
issue.  Despite what level of support a hardware vendor is providing,
the kernel very much needs an accurate and up-to-date list of
vulnerable CPUs.  More reports like this are very welcome.

* Client Skylakes are CPUID 406E3/506E3 which is family 6, models
  0x4E and 0x5E, aka INTEL_FAM6_SKYLAKE and INTEL_FAM6_SKYLAKE_L.

Reported-by: Michael Zhivich <mzhivich@akamai.com>
Fixes: 8974eb5882 ("x86/speculation: Add Gather Data Sampling mitigation")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2023-08-31 20:20:31 +02:00
Sean Christopherson
d10f3780bc KVM: x86/mmu: Include mmu.h in spte.h
Explicitly include mmu.h in spte.h instead of relying on the "parent" to
include mmu.h.  spte.h references a variety of macros and variables that
are defined/declared in mmu.h, and so including spte.h before (or instead
of) mmu.h will result in build errors, e.g.

  arch/x86/kvm/mmu/spte.h: In function ‘is_mmio_spte’:
  arch/x86/kvm/mmu/spte.h:242:23: error: ‘enable_mmio_caching’ undeclared
    242 |                likely(enable_mmio_caching);
        |                       ^~~~~~~~~~~~~~~~~~~

  arch/x86/kvm/mmu/spte.h: In function ‘is_large_pte’:
  arch/x86/kvm/mmu/spte.h:302:22: error: ‘PT_PAGE_SIZE_MASK’ undeclared
    302 |         return pte & PT_PAGE_SIZE_MASK;
        |                      ^~~~~~~~~~~~~~~~~

  arch/x86/kvm/mmu/spte.h: In function ‘is_dirty_spte’:
  arch/x86/kvm/mmu/spte.h:332:56: error: ‘PT_WRITABLE_MASK’ undeclared
    332 |         return dirty_mask ? spte & dirty_mask : spte & PT_WRITABLE_MASK;
        |                                                        ^~~~~~~~~~~~~~~~

Fixes: 5a9624affe ("KVM: mmu: extract spte.h and spte.c")
Link: https://lore.kernel.org/r/20230808224059.2492476-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:25 -04:00
Sean Christopherson
0e3223d8d0 KVM: x86/mmu: Use dummy root, backed by zero page, for !visible guest roots
When attempting to allocate a shadow root for a !visible guest root gfn,
e.g. that resides in MMIO space, load a dummy root that is backed by the
zero page instead of immediately synthesizing a triple fault shutdown
(using the zero page ensures any attempt to translate memory will generate
a !PRESENT fault and thus VM-Exit).

Unless the vCPU is racing with memslot activity, KVM will inject a page
fault due to not finding a visible slot in FNAME(walk_addr_generic), i.e.
the end result is mostly same, but critically KVM will inject a fault only
*after* KVM runs the vCPU with the bogus root.

Waiting to inject a fault until after running the vCPU fixes a bug where
KVM would bail from nested VM-Enter if L1 tried to run L2 with TDP enabled
and a !visible root.  Even though a bad root will *probably* lead to
shutdown, (a) it's not guaranteed and (b) the CPU won't read the
underlying memory until after VM-Enter succeeds.  E.g. if L1 runs L2 with
a VMX preemption timer value of '0', then architecturally the preemption
timer VM-Exit is guaranteed to occur before the CPU executes any
instruction, i.e. before the CPU needs to translate a GPA to a HPA (so
long as there are no injected events with higher priority than the
preemption timer).

If KVM manages to get to FNAME(fetch) with a dummy root, e.g. because
userspace created a memslot between installing the dummy root and handling
the page fault, simply unload the MMU to allocate a new root and retry the
instruction.  Use KVM_REQ_MMU_FREE_OBSOLETE_ROOTS to drop the root, as
invoking kvm_mmu_free_roots() while holding mmu_lock would deadlock, and
conceptually the dummy root has indeeed become obsolete.  The only
difference versus existing usage of KVM_REQ_MMU_FREE_OBSOLETE_ROOTS is
that the root has become obsolete due to memslot *creation*, not memslot
deletion or movement.

Reported-by: Reima Ishii <ishiir@g.ecc.u-tokyo.ac.jp>
Cc: Yu Zhang <yu.c.zhang@linux.intel.com>
Link: https://lore.kernel.org/r/20230729005200.1057358-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:24 -04:00
Sean Christopherson
b5b359ac30 KVM: x86/mmu: Disallow guest from using !visible slots for page tables
Explicitly inject a page fault if guest attempts to use a !visible gfn
as a page table.  kvm_vcpu_gfn_to_hva_prot() will naturally handle the
case where there is no memslot, but doesn't catch the scenario where the
gfn points at a KVM-internal memslot.

Letting the guest backdoor its way into accessing KVM-internal memslots
isn't dangerous on its own, e.g. at worst the guest can crash itself, but
disallowing the behavior will simplify fixing how KVM handles !visible
guest root gfns (immediately synthesizing a triple fault when loading the
root is architecturally wrong).

Link: https://lore.kernel.org/r/20230729005200.1057358-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:23 -04:00
Sean Christopherson
2c6d4c27b9 KVM: x86/mmu: Harden TDP MMU iteration against root w/o shadow page
Explicitly check that tdp_iter_start() is handed a valid shadow page
to harden KVM against bugs, e.g. if KVM calls into the TDP MMU with an
invalid or shadow MMU root (which would be a fatal KVM bug), the shadow
page pointer will be NULL.

Opportunistically stop the TDP MMU iteration instead of continuing on
with garbage if the incoming root is bogus.  Attempting to walk a garbage
root is more likely to caused major problems than doing nothing.

Cc: Yu Zhang <yu.c.zhang@linux.intel.com>
Link: https://lore.kernel.org/r/20230729005200.1057358-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:22 -04:00
Sean Christopherson
c30e000e69 KVM: x86/mmu: Harden new PGD against roots without shadow pages
Harden kvm_mmu_new_pgd() against NULL pointer dereference bugs by sanity
checking that the target root has an associated shadow page prior to
dereferencing said shadow page.  The code in question is guaranteed to
only see roots with shadow pages as fast_pgd_switch() explicitly frees the
current root if it doesn't have a shadow page, i.e. is a PAE root, and
that in turn prevents valid roots from being cached, but that's all very
subtle.

Link: https://lore.kernel.org/r/20230729005200.1057358-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:21 -04:00
Sean Christopherson
c5f2d5645f KVM: x86/mmu: Add helper to convert root hpa to shadow page
Add a dedicated helper for converting a root hpa to a shadow page in
anticipation of using a "dummy" root to handle the scenario where KVM
needs to load a valid shadow root (from hardware's perspective), but
the guest doesn't have a visible root to shadow.  Similar to PAE roots,
the dummy root won't have an associated kvm_mmu_page and will need special
handling when finding a shadow page given a root.

Opportunistically retrieve the root shadow page in kvm_mmu_sync_roots()
*after* verifying the root is unsync (the dummy root can never be unsync).

Link: https://lore.kernel.org/r/20230729005200.1057358-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:20 -04:00
Sean Christopherson
f22b1e8500 KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers
Get/put references to KVM when a page-track notifier is (un)registered
instead of relying on the caller to do so.  Forcing the caller to do the
bookkeeping is unnecessary and adds one more thing for users to get
wrong, e.g. see commit 9ed1fdee9e ("drm/i915/gvt: Get reference to KVM
iff attachment to VM is successful").

Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-29-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:19 -04:00
Sean Christopherson
96316a0670 KVM: x86/mmu: Drop @slot param from exported/external page-track APIs
Refactor KVM's exported/external page-track, a.k.a. write-track, APIs
to take only the gfn and do the required memslot lookup in KVM proper.
Forcing users of the APIs to get the memslot unnecessarily bleeds
KVM internals into KVMGT and complicates usage of the APIs.

No functional change intended.

Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-28-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:18 -04:00
Sean Christopherson
427c76aed2 KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled
Bug the VM if something attempts to write-track a gfn, but write-tracking
isn't enabled.  The VM is doomed (and KVM has an egregious bug) if KVM or
KVMGT wants to shadow guest page tables but can't because write-tracking
isn't enabled.

Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-27-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:17 -04:00
Sean Christopherson
e18c5429e0 KVM: x86/mmu: Assert that correct locks are held for page write-tracking
When adding/removing gfns to/from write-tracking, assert that mmu_lock
is held for write, and that either slots_lock or kvm->srcu is held.
mmu_lock must be held for write to protect gfn_write_track's refcount,
and SRCU or slots_lock must be held to protect the memslot itself.

Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-26-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:16 -04:00
Sean Christopherson
7b574863e7 KVM: x86/mmu: Rename page-track APIs to reflect the new reality
Rename the page-track APIs to capture that they're all about tracking
writes, now that the facade of supporting multiple modes is gone.

Opportunstically replace "slot" with "gfn" in anticipation of removing
the @slot param from the external APIs.

No functional change intended.

Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-25-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:15 -04:00
Sean Christopherson
338068b5be KVM: x86/mmu: Drop infrastructure for multiple page-track modes
Drop "support" for multiple page-track modes, as there is no evidence
that array-based and refcounted metadata is the optimal solution for
other modes, nor is there any evidence that other use cases, e.g. for
access-tracking, will be a good fit for the page-track machinery in
general.

E.g. one potential use case of access-tracking would be to prevent guest
access to poisoned memory (from the guest's perspective).  In that case,
the number of poisoned pages is likely to be a very small percentage of
the guest memory, and there is no need to reference count the number of
access-tracking users, i.e. expanding gfn_track[] for a new mode would be
grossly inefficient.  And for poisoned memory, host userspace would also
likely want to trap accesses, e.g. to inject #MC into the guest, and that
isn't currently supported by the page-track framework.

A better alternative for that poisoned page use case is likely a
variation of the proposed per-gfn attributes overlay (linked), which
would allow efficiently tracking the sparse set of poisoned pages, and by
default would exit to userspace on access.

Link: https://lore.kernel.org/all/Y2WB48kD0J4VGynX@google.com
Cc: Ben Gardon <bgardon@google.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-24-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:14 -04:00
Sean Christopherson
e998fb1a30 KVM: x86/mmu: Use page-track notifiers iff there are external users
Disable the page-track notifier code at compile time if there are no
external users, i.e. if CONFIG_KVM_EXTERNAL_WRITE_TRACKING=n.  KVM itself
now hooks emulated writes directly instead of relying on the page-track
mechanism.

Provide a stub for "struct kvm_page_track_notifier_node" so that including
headers directly from the command line, e.g. for testing include guards,
doesn't fail due to a struct having an incomplete type.

Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-23-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:14 -04:00
Sean Christopherson
58ea7cf700 KVM: x86/mmu: Move KVM-only page-track declarations to internal header
Bury the declaration of the page-track helpers that are intended only for
internal KVM use in a "private" header.  In addition to guarding against
unwanted usage of the internal-only helpers, dropping their definitions
avoids exposing other structures that should be KVM-internal, e.g. for
memslots.  This is a baby step toward making kvm_host.h a KVM-internal
header in the very distant future.

Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-22-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:08:13 -04:00
Yan Zhao
d104d5bbbc KVM: x86: Remove the unused page-track hook track_flush_slot()
Remove ->track_remove_slot(), there are no longer any users and it's
unlikely a "flush" hook will ever be the correct API to provide to an
external page-track user.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-21-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:07:26 -04:00
Yan Zhao
b83ab124de KVM: x86: Add a new page-track hook to handle memslot deletion
Add a new page-track hook, track_remove_region(), that is called when a
memslot DELETE operation is about to be committed.  The "remove" hook
will be used by KVMGT and will effectively replace the existing
track_flush_slot() altogether now that KVM itself doesn't rely on the
"flush" hook either.

The "flush" hook is flawed as it's invoked before the memslot operation
is guaranteed to succeed, i.e. KVM might ultimately keep the existing
memslot without notifying external page track users, a.k.a. KVMGT.  In
practice, this can't currently happen on x86, but there are no guarantees
that won't change in the future, not to mention that "flush" does a very
poor job of describing what is happening.

Pass in the gfn+nr_pages instead of the slot itself so external users,
i.e. KVMGT, don't need to exposed to KVM internals (memslots).  This will
help set the stage for additional cleanups to the page-track APIs.

Opportunistically align the existing srcu_read_lock_held() usage so that
the new case doesn't stand out like a sore thumb (and not aligning the
new code makes bots unhappy).

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-19-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:07:25 -04:00
Sean Christopherson
c70934e0ab KVM: x86: Reject memslot MOVE operations if KVMGT is attached
Disallow moving memslots if the VM has external page-track users, i.e. if
KVMGT is being used to expose a virtual GPU to the guest, as KVMGT doesn't
correctly handle moving memory regions.

Note, this is potential ABI breakage!  E.g. userspace could move regions
that aren't shadowed by KVMGT without harming the guest.  However, the
only known user of KVMGT is QEMU, and QEMU doesn't move generic memory
regions.  KVM's own support for moving memory regions was also broken for
multiple years (albeit for an edge case, but arguably moving RAM is
itself an edge case), e.g. see commit edd4fa37ba ("KVM: x86: Allocate
new rmap and large page tracking when moving memslot").

Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-17-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 14:07:23 -04:00
Sean Christopherson
b271e17def KVM: drm/i915/gvt: Drop @vcpu from KVM's ->track_write() hook
Drop @vcpu from KVM's ->track_write() hook provided for external users of
the page-track APIs now that KVM itself doesn't use the page-track
mechanism.

Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-16-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:49:01 -04:00
Sean Christopherson
932844462a KVM: x86/mmu: Don't bounce through page-track mechanism for guest PTEs
Don't use the generic page-track mechanism to handle writes to guest PTEs
in KVM's MMU.  KVM's MMU needs access to information that should not be
exposed to external page-track users, e.g. KVM needs (for some definitions
of "need") the vCPU to query the current paging mode, whereas external
users, i.e. KVMGT, have no ties to the current vCPU and so should never
need the vCPU.

Moving away from the page-track mechanism will allow dropping use of the
page-track mechanism for KVM's own MMU, and will also allow simplifying
and cleaning up the page-track APIs.

Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-15-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:49:00 -04:00
Sean Christopherson
eeb87272a3 KVM: x86/mmu: Don't rely on page-track mechanism to flush on memslot change
Call kvm_mmu_zap_all_fast() directly when flushing a memslot instead of
bouncing through the page-track mechanism.  KVM (unfortunately) needs to
zap and flush all page tables on memslot DELETE/MOVE irrespective of
whether KVM is shadowing guest page tables.

This will allow changing KVM to register a page-track notifier on the
first shadow root allocation, and will also allow deleting the misguided
kvm_page_track_flush_slot() hook itself once KVM-GT also moves to a
different method for reacting to memslot changes.

No functional change intended.

Cc: Yan Zhao <yan.y.zhao@intel.com>
Link: https://lore.kernel.org/r/20221110014821.1548347-2-seanjc@google.com
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-14-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:49:00 -04:00
Sean Christopherson
db0d70e610 KVM: x86/mmu: Move kvm_arch_flush_shadow_{all,memslot}() to mmu.c
Move x86's implementation of kvm_arch_flush_shadow_{all,memslot}() into
mmu.c, and make kvm_mmu_zap_all() static as it was globally visible only
for kvm_arch_flush_shadow_all().  This will allow refactoring
kvm_arch_flush_shadow_memslot() to call kvm_mmu_zap_all() directly without
having to expose kvm_mmu_zap_all_fast() outside of mmu.c.  Keeping
everything in mmu.c will also likely simplify supporting TDX, which
intends to do zap only relevant SPTEs on memslot updates.

No functional change intended.

Suggested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:59 -04:00
Sean Christopherson
52e322eda3 KVM: x86/mmu: BUG() in rmap helpers iff CONFIG_BUG_ON_DATA_CORRUPTION=y
Introduce KVM_BUG_ON_DATA_CORRUPTION() and use it in the low-level rmap
helpers to convert the existing BUG()s to WARN_ON_ONCE() when the kernel
is built with CONFIG_BUG_ON_DATA_CORRUPTION=n, i.e. does NOT want to BUG()
on corruption of host kernel data structures.  Environments that don't
have infrastructure to automatically capture crash dumps, i.e. aren't
likely to enable CONFIG_BUG_ON_DATA_CORRUPTION=y, are typically better
served overall by WARN-and-continue behavior (for the kernel, the VM is
dead regardless), as a BUG() while holding mmu_lock all but guarantees
the _best_ case scenario is a panic().

Make the BUG()s conditional instead of removing/replacing them entirely as
there's a non-zero chance (though by no means a guarantee) that the damage
isn't contained to the target VM, e.g. if no rmap is found for a SPTE then
KVM may be double-zapping the SPTE, i.e. has already freed the memory the
SPTE pointed at and thus KVM is reading/writing memory that KVM no longer
owns.

Link: https://lore.kernel.org/all/20221129191237.31447-1-mizhang@google.com
Suggested-by: Mingwei Zhang <mizhang@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: Jim Mattson <jmattson@google.com>
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230729004722.1056172-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:50 -04:00
Mingwei Zhang
069f30c619 KVM: x86/mmu: Plumb "struct kvm" all the way to pte_list_remove()
Plumb "struct kvm" all the way to pte_list_remove() to allow the usage of
KVM_BUG() and/or KVM_BUG_ON().  This will allow killing only the offending
VM instead of doing BUG() if the kernel is built with
CONFIG_BUG_ON_DATA_CORRUPTION=n, i.e. does NOT want to BUG() if KVM's data
structures (rmaps) appear to be corrupted.

Signed-off-by: Mingwei Zhang <mizhang@google.com>
[sean: tweak changelog]
Link: https://lore.kernel.org/r/20230729004722.1056172-12-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:49 -04:00
Sean Christopherson
3328dfe0ea KVM: x86/mmu: Use BUILD_BUG_ON_INVALID() for KVM_MMU_WARN_ON() stub
Use BUILD_BUG_ON_INVALID() instead of an empty do-while loop to stub out
KVM_MMU_WARN_ON() when CONFIG_KVM_PROVE_MMU=n, that way _some_ build
issues with the usage of KVM_MMU_WARN_ON() will be dected even if the
kernel is using the stubs, e.g. basic syntax errors will be detected.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230729004722.1056172-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:48 -04:00
Sean Christopherson
870d4d4ed8 KVM: x86/mmu: Replace MMU_DEBUG with proper KVM_PROVE_MMU Kconfig
Replace MMU_DEBUG, which requires manually modifying KVM to enable the
macro, with a proper Kconfig, KVM_PROVE_MMU.  Now that pgprintk() and
rmap_printk() are gone, i.e. the macro guards only KVM_MMU_WARN_ON() and
won't flood the kernel logs, enabling the option for debug kernels is both
desirable and feasible.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230729004722.1056172-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:47 -04:00
Sean Christopherson
72e2fb24a0 KVM: x86/mmu: Bug the VM if a vCPU ends up in long mode without PAE enabled
Promote the ASSERT(), which is quite dead code in KVM, into a KVM_BUG_ON()
for KVM's sanity check that CR4.PAE=1 if the vCPU is in long mode when
performing a walk of guest page tables.  The sanity is quite cheap since
neither EFER nor CR4.PAE requires a VMREAD, especially relative to the
cost of walking the guest page tables.

More importantly, the sanity check would have prevented the true badness
fixed by commit 112e66017b ("KVM: nVMX: add missing consistency checks
for CR0 and CR4").  The missed consistency check resulted in some versions
of KVM corrupting the on-stack guest_walker structure due to KVM thinking
there are 4/5 levels of page tables, but wiring up the MMU hooks to point
at the paging32 implementation, which only allocates space for two levels
of page tables in "struct guest_walker32".

Queue a page fault for injection if the assertion fails, as both callers,
FNAME(gva_to_gpa) and FNAME(walk_addr_generic), assume that walker.fault
contains sane info on a walk failure.  E.g. not populating the fault info
could result in KVM consuming and/or exposing uninitialized stack data
before the vCPU is kicked out to userspace, which doesn't happen until
KVM checks for KVM_REQ_VM_DEAD on the next enter.

Move the check below the initialization of "pte_access" so that the
aforementioned to-be-injected page fault doesn't consume uninitialized
stack data.  The information _shouldn't_ reach the guest or userspace,
but there's zero downside to being paranoid in this case.

Link: https://lore.kernel.org/r/20230729004722.1056172-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:47 -04:00
Sean Christopherson
20ba462dfd KVM: x86/mmu: Convert "runtime" WARN_ON() assertions to WARN_ON_ONCE()
Convert all "runtime" assertions, i.e. assertions that can be triggered
while running vCPUs, from WARN_ON() to WARN_ON_ONCE().  Every WARN in the
MMU that is tied to running vCPUs, i.e. not contained to loading and
initializing KVM, is likely to fire _a lot_ when it does trigger.  E.g. if
KVM ends up with a bug that causes a root to be invalidated before the
page fault handler is invoked, pretty much _every_ page fault VM-Exit
triggers the WARN.

If a WARN is triggered frequently, the resulting spam usually causes a lot
of damage of its own, e.g. consumes resources to log the WARN and pollutes
the kernel log, often to the point where other useful information can be
lost.  In many case, the damage caused by the spam is actually worse than
the bug itself, e.g. KVM can almost always recover from an unexpectedly
invalid root.

On the flip side, warning every time is rarely helpful for debug and
triage, i.e. a single splat is usually sufficient to point a debugger in
the right direction, and automated testing, e.g. syzkaller, typically runs
with warn_on_panic=1, i.e. will never get past the first WARN anyways.

Lastly, when an assertions fails multiple times, the stack traces in KVM
are almost always identical, i.e. the full splat only needs to be captured
once.  And _if_ there is value in captruing information about the failed
assert, a ratelimited printk() is sufficient and less likely to rack up a
large amount of collateral damage.

Link: https://lore.kernel.org/r/20230729004722.1056172-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:44 -04:00
Sean Christopherson
0fe6370eb3 KVM: x86/mmu: Rename MMU_WARN_ON() to KVM_MMU_WARN_ON()
Rename MMU_WARN_ON() to make it super obvious that the assertions are
all about KVM's MMU, not the primary MMU.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230729004722.1056172-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:43 -04:00
Sean Christopherson
58da926caa KVM: x86/mmu: Cleanup sanity check of SPTEs at SP free
Massage the error message for the sanity check on SPTEs when freeing a
shadow page to be more verbose, and to print out all shadow-present SPTEs,
not just the first SPTE encountered.  Printing all SPTEs can be quite
valuable for debug, e.g. highlights whether the leak is a one-off or
widepsread, or possibly the result of memory corruption (something else
in the kernel stomping on KVM's SPTEs).

Opportunistically move the MMU_WARN_ON() into the helper itself, which
will allow a future cleanup to use BUILD_BUG_ON_INVALID() as the stub for
MMU_WARN_ON().  BUILD_BUG_ON_INVALID() works as intended and results in
the compiler complaining about is_empty_shadow_page() not being declared.

Link: https://lore.kernel.org/r/20230729004722.1056172-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:43 -04:00
Sean Christopherson
242a6dd8da KVM: x86/mmu: Avoid pointer arithmetic when iterating over SPTEs
Replace the pointer arithmetic used to iterate over SPTEs in
is_empty_shadow_page() with more standard interger-based iteration.

No functional change intended.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230729004722.1056172-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:42 -04:00
Sean Christopherson
c4f92cfe02 KVM: x86/mmu: Delete the "dbg" module param
Delete KVM's "dbg" module param now that its usage in KVM is gone (it
used to guard pgprintk() and rmap_printk()).

Link: https://lore.kernel.org/r/20230729004722.1056172-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-31 13:48:41 -04:00