Re: [GIT PULL] KVM: x86: Misc changes for 6.7

[Paolo Bonzini]

On Fri, Oct 27, 2023 at 10:49 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> A truly miscellaneous collection of patches this time around.  David M's PML
> fix obviously belongs in the MMU pull request, but I applied it to the wrong
> branch and didn't want to rebase for such a silly thing.
>
> The following changes since commit 5804c19b80bf625c6a9925317f845e497434d6d3:
>
>   Merge tag 'kvm-riscv-fixes-6.6-1' of https://github.com/kvm-riscv/linux into HEAD (2023-09-23 05:35:55 -0400)
>
> are available in the Git repository at:
>
>   https://github.com/kvm-x86/linux.git tags/kvm-x86-misc-6.7
>
> for you to fetch changes up to 2770d4722036d6bd24bcb78e9cd7f6e572077d03:
>
>   KVM: x86: Ignore MSR_AMD64_TW_CFG access (2023-10-19 10:55:14 -0700)

Pulled, thanks.

Paolo

>
> ----------------------------------------------------------------
> KVM x86 misc changes for 6.7:
>
>  - Add CONFIG_KVM_MAX_NR_VCPUS to allow supporting up to 4096 vCPUs without
>    forcing more common use cases to eat the extra memory overhead.
>
>  - Add IBPB and SBPB virtualization support.
>
>  - Fix a bug where restoring a vCPU snapshot that was taken within 1 second of
>    creating the original vCPU would cause KVM to try to synchronize the vCPU's
>    TSC and thus clobber the correct TSC being set by userspace.
>
>  - Compute guest wall clock using a single TSC read to avoid generating an
>    inaccurate time, e.g. if the vCPU is preempted between multiple TSC reads.
>
>  - "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which complain
>     about a "Firmware Bug" if the bit isn't set for select F/M/S combos.
>
>  - Don't apply side effects to Hyper-V's synthetic timer on writes from
>    userspace to fix an issue where the auto-enable behavior can trigger
>    spurious interrupts, i.e. do auto-enabling only for guest writes.
>
>  - Remove an unnecessary kick of all vCPUs when synchronizing the dirty log
>    without PML enabled.
>
>  - Advertise "support" for non-serializing FS/GS base MSR writes as appropriate.
>
>  - Use octal notation for file permissions through KVM x86.
>
>  - Fix a handful of typo fixes and warts.
>
> ----------------------------------------------------------------
> David Matlack (1):
>       KVM: x86/mmu: Stop kicking vCPUs to sync the dirty log when PML is disabled
>
> David Woodhouse (1):
>       KVM: x86: Refine calculation of guest wall clock to use a single TSC read
>
> Dongli Zhang (1):
>       KVM: x86: remove always-false condition in kvmclock_sync_fn
>
> Jim Mattson (4):
>       KVM: x86: Allow HWCR.McStatusWrEn to be cleared once set
>       KVM: x86: Virtualize HWCR.TscFreqSel[bit 24]
>       KVM: selftests: Test behavior of HWCR, a.k.a. MSR_K7_HWCR
>       x86: KVM: Add feature flag for CPUID.80000021H:EAX[bit 1]
>
> Josh Poimboeuf (2):
>       KVM: x86: Add IBPB_BRTYPE support
>       KVM: x86: Add SBPB support
>
> Kyle Meyer (1):
>       KVM: x86: Add CONFIG_KVM_MAX_NR_VCPUS to allow up to 4096 vCPUs
>
> Liang Chen (1):
>       KVM: x86: remove the unused assigned_dev_head from kvm_arch
>
> Like Xu (1):
>       KVM: x86: Don't sync user-written TSC against startup values
>
> Maciej S. Szmigiero (1):
>       KVM: x86: Ignore MSR_AMD64_TW_CFG access
>
> Michal Luczaj (2):
>       KVM: x86: Remove redundant vcpu->arch.cr0 assignments
>       KVM: x86: Force TLB flush on userspace changes to special registers
>
> Mingwei Zhang (1):
>       KVM: x86: Update the variable naming in kvm_x86_ops.sched_in()
>
> Nicolas Saenz Julienne (1):
>       KVM: x86: hyper-v: Don't auto-enable stimer on write from user-space
>
> Peng Hao (1):
>       KVM: x86: Use octal for file permission
>
>  arch/x86/include/asm/cpufeatures.h                 |   1 +
>  arch/x86/include/asm/kvm_host.h                    |  12 +-
>  arch/x86/include/asm/msr-index.h                   |   1 +
>  arch/x86/kvm/Kconfig                               |  11 ++
>  arch/x86/kvm/cpuid.c                               |   8 +-
>  arch/x86/kvm/cpuid.h                               |   3 +-
>  arch/x86/kvm/hyperv.c                              |  10 +-
>  arch/x86/kvm/smm.c                                 |   1 -
>  arch/x86/kvm/svm/svm.c                             |   2 +-
>  arch/x86/kvm/vmx/vmx.c                             |  20 +--
>  arch/x86/kvm/x86.c                                 | 195 ++++++++++++++++-----
>  arch/x86/kvm/x86.h                                 |   1 +
>  arch/x86/kvm/xen.c                                 |   4 +-
>  tools/testing/selftests/kvm/Makefile               |   1 +
>  tools/testing/selftests/kvm/x86_64/hwcr_msr_test.c |  47 +++++
>  15 files changed, 251 insertions(+), 66 deletions(-)
>  create mode 100644 tools/testing/selftests/kvm/x86_64/hwcr_msr_test.c
>