Re: [GIT PULL] KVM: x86: Fixes for 6.9-rcN
From: Paolo Bonzini
Date: Tue Apr 16 2024 - 12:55:35 EST
On Thu, Apr 11, 2024 at 10:35 PM Sean Christopherson <seanjc@googlecom> wrote:
>
> Please pull a big pile of fixes for 6.9. Many of these were sent even before
> the 6.9 merge window, but I was on vacation until rc2, and things piled up.
>
> The back half of the commits were _just_ rebased to drop my version of the
> LVTPC masking fixes, but that's your fault. :-) For giggles, I also pushed
> kvm-x86 tags/kvm-x86-fixed-6.9-rcN-unrebased if you or anyone else want a paper
> trail for the pre-rebase commits.
>
> Note, there's a perf change in here that didn't get an Ack from anyone, but the
> fixes have been on-list for over a month, and I can't imagine anyone objecting
> to adding a new feature flag to x86_pmu_capability, which for all intents and
> purposes exists purely for KVM.
>
> Thanks!
Pulled, thanks.
Paolo
> The following changes since commit fec50db7033ea478773b159e0e2efb135270e3b7:
>
> Linux 6.9-rc3 (2024-04-07 13:22:46 -0700)
>
> are available in the Git repository at:
>
> https://github.com/kvm-x86/linux.git tags/kvm-x86-fixes-6.9-rcN
>
> for you to fetch changes up to eefb85b3f0310c2f4149c50cb9b13094ed1dde25:
>
> KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start() (2024-04-11 12:58:53 -0700)
>
> ----------------------------------------------------------------
> KVM fixes for 6.9-rcN:
>
> - Fix a mostly benign bug in the gfn_to_pfn_cache infrastructure where KVM
> would allow userspace to refresh the cache with a bogus GPA. The bug has
> existed for quite some time, but was exposed by a new sanity check added in
> 6.9 (to ensure a cache is either GPA-based or HVA-based).
>
> - Drop an unused param from gfn_to_pfn_cache_invalidate_start() that got left
> behind during a 6.9 cleanup.
>
> - Disable support for virtualizing adaptive PEBS, as KVM's implementation is
> architecturally broken and can leak host LBRs to the guest.
>
> - Fix a bug where KVM neglects to set the enable bits for general purpose
> counters in PERF_GLOBAL_CTRL when initializing the virtual PMU. Both Intel
> and AMD architectures require the bits to be set at RESET in order for v2
> PMUs to be backwards compatible with software that was written for v1 PMUs,
> i.e. for software that will never manually set the global enables.
>
> - Disable LBR virtualization on CPUs that don't support LBR callstacks, as
> KVM unconditionally uses PERF_SAMPLE_BRANCH_CALL_STACK when creating the
> virtual LBR perf event, i.e. KVM will always fail to create LBR events on
> such CPUs.
>
> - Fix a math goof in x86's hugepage logic for KVM_SET_MEMORY_ATTRIBUTES that
> results in an array overflow (detected by KASAN).
>
> - Fix a flaw in the max_guest_memory selftest that results in it exhausting
> the supply of ucall structures when run with more than 256 vCPUs.
>
> - Mark KVM_MEM_READONLY as supported for RISC-V in set_memory_region_test.
>
> - Fix a bug where KVM incorrectly thinks a TDP MMU root is an indirect shadow
> root due KVM unnecessarily clobbering root_role.direct when userspace sets
> guest CPUID.
>
> - Fix a dirty logging bug in the where KVM fails to write-protect TDP MMU
> SPTEs used for L2 if Page-Modification Logging is enabled for L1 and the L1
> hypervisor is NOT using EPT (if nEPT is enabled, KVM doesn't use the TDP MMU
> to run L2). For simplicity, KVM always disables PML when running L2, but
> the TDP MMU wasn't accounting for root-specific conditions that force write-
> protect based dirty logging.
>
> ----------------------------------------------------------------
> Andrew Jones (1):
> KVM: selftests: fix supported_flags for riscv
>
> David Matlack (4):
> KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status
> KVM: x86/mmu: Remove function comments above clear_dirty_{gfn_range,pt_masked}()
> KVM: x86/mmu: Fix and clarify comments about clearing D-bit vs. write-protecting
> KVM: selftests: Add coverage of EPT-disabled to vmx_dirty_log_test
>
> Maxim Levitsky (1):
> KVM: selftests: fix max_guest_memory_test with more that 256 vCPUs
>
> Rick Edgecombe (1):
> KVM: x86/mmu: x86: Don't overflow lpage_info when checking attributes
>
> Sean Christopherson (11):
> KVM: Add helpers to consolidate gfn_to_pfn_cache's page split check
> KVM: Check validity of offset+length of gfn_to_pfn_cache prior to activation
> KVM: Explicitly disallow activatating a gfn_to_pfn_cache with INVALID_GPA
> KVM: x86/pmu: Disable support for adaptive PEBS
> KVM: x86/pmu: Set enable bits for GP counters in PERF_GLOBAL_CTRL at "RESET"
> KVM: selftests: Verify post-RESET value of PERF_GLOBAL_CTRL in PMCs test
> KVM: VMX: Snapshot LBR capabilities during module initialization
> perf/x86/intel: Expose existence of callback support to KVM
> KVM: VMX: Disable LBR virtualization if the CPU doesn't support LBR callstacks
> KVM: x86/mmu: Precisely invalidate MMU root_role during CPUID update
> KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start()
>
> Tao Su (1):
> KVM: VMX: Ignore MKTME KeyID bits when intercepting #PF for allow_smaller_maxphyaddr
>
> arch/x86/events/intel/lbr.c | 1 +
> arch/x86/include/asm/perf_event.h | 1 +
> arch/x86/kvm/mmu/mmu.c | 9 ++--
> arch/x86/kvm/mmu/tdp_mmu.c | 51 ++++++++----------
> arch/x86/kvm/pmu.c | 16 +++++-
> arch/x86/kvm/vmx/pmu_intel.c | 2 +-
> arch/x86/kvm/vmx/vmx.c | 41 ++++++++++++---
> arch/x86/kvm/vmx/vmx.h | 6 ++-
> .../testing/selftests/kvm/max_guest_memory_test.c | 15 +++---
> .../testing/selftests/kvm/set_memory_region_test.c | 2 +-
> .../selftests/kvm/x86_64/pmu_counters_test.c | 20 +++++++-
> .../selftests/kvm/x86_64/vmx_dirty_log_test.c | 60 +++++++++++++++++-----
> virt/kvm/kvm_main.c | 3 +-
> virt/kvm/kvm_mm.h | 6 +--
> virt/kvm/pfncache.c | 50 ++++++++++++------
> 15 files changed, 194 insertions(+), 89 deletions(-)
>