Re: [PATCH 0/9] KVM: x86: Add a quirk for feature MSR initialization
From: Sean Christopherson
Date: Thu Oct 31 2024 - 15:55:23 EST
On Fri, 02 Aug 2024 11:55:02 -0700, Sean Christopherson wrote:
> The primary goal of this series to fix an issue where KVM's initialization
> of feature MSRs during vCPU creation results in a failed save/restore of
> PERF_CAPABILITIES. If userspace configures the VM to _not_ have a PMU,
> because KVM initializes the vCPU's PERF_CAPABILTIIES, trying to save/restore
> the non-zero value will be rejected by the destination.
>
> The secondary goal is to try and avoid such goofs in the future, by making
> it explicitly clear that userspace owns the vCPU model.
>
> [...]
Applied to kvm-x86 misc, thanks!
[1/9] KVM: x86: Co-locate initialization of feature MSRs in kvm_arch_vcpu_create()
https://github.com/kvm-x86/linux/commit/383383cfd202
[2/9] KVM: x86: Disallow changing MSR_PLATFORM_INFO after vCPU has run
https://github.com/kvm-x86/linux/commit/d76a5e78f16d
[3/9] KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration
https://github.com/kvm-x86/linux/commit/088b8eeb25ec
[4/9] KVM: x86: Reject userspace attempts to access PERF_CAPABILITIES w/o PDCM
https://github.com/kvm-x86/linux/commit/c2eb2d0318c0
[5/9] KVM: VMX: Remove restriction that PMU version > 0 for PERF_CAPABILITIES
https://github.com/kvm-x86/linux/commit/bae593b20e92
[6/9] KVM: x86: Reject userspace attempts to access ARCH_CAPABILITIES w/o support
https://github.com/kvm-x86/linux/commit/83a5fe6cf1eb
[7/9] KVM: x86: Remove ordering check b/w MSR_PLATFORM_INFO and MISC_FEATURES_ENABLES
https://github.com/kvm-x86/linux/commit/9d2dcfb82db1
[8/9] KVM: selftests: Verify get/set PERF_CAPABILITIES w/o guest PDMC behavior
https://github.com/kvm-x86/linux/commit/6a4511f8602f
[9/9] KVM: selftests: Add a testcase for disabling feature MSRs init quirk
https://github.com/kvm-x86/linux/commit/58a7368f104d
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https://github.com/kvm-x86/linux/tree/next