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From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Like Xu <like.xu.linux@gmail.com>
Subject: Re: [PATCH v2 02/21] KVM: x86: Add a helper to query whether or not a vCPU has ever run
Date: Tue, 14 Feb 2023 14:35:48 +0800	[thread overview]
Message-ID: <08e86395-d67a-b24e-5256-d7f78f06873d@intel.com> (raw)
In-Reply-To: <20230210003148.2646712-3-seanjc@google.com>

On 2/10/2023 8:31 AM, Sean Christopherson wrote:
> Add a helper to query if a vCPU has run so that KVM doesn't have to open
> code the check on last_vmentry_cpu being set to a magic value.
> 
> No functional change intended.
> 
> Suggested-by: Xiaoyao Li <xiaoyao.li@intel.com>
> Cc: Like Xu <like.xu.linux@gmail.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>

> ---
>   arch/x86/kvm/cpuid.c   | 2 +-
>   arch/x86/kvm/mmu/mmu.c | 2 +-
>   arch/x86/kvm/x86.h     | 5 +++++
>   3 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 8f8edeaf8177..448d627ce891 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -420,7 +420,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
>   	 * KVM_SET_CPUID{,2} again. To support this legacy behavior, check
>   	 * whether the supplied CPUID data is equal to what's already set.
>   	 */
> -	if (vcpu->arch.last_vmentry_cpu != -1) {
> +	if (kvm_vcpu_has_run(vcpu)) {
>   		r = kvm_cpuid_check_equal(vcpu, e2, nent);
>   		if (r)
>   			return r;
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index c91ee2927dd7..b0693195273b 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -5393,7 +5393,7 @@ void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu)
>   	 * Changing guest CPUID after KVM_RUN is forbidden, see the comment in
>   	 * kvm_arch_vcpu_ioctl().
>   	 */
> -	KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm);
> +	KVM_BUG_ON(kvm_vcpu_has_run(vcpu), vcpu->kvm);
>   }
>   
>   void kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
> diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
> index a8167b47b8c8..754190af1791 100644
> --- a/arch/x86/kvm/x86.h
> +++ b/arch/x86/kvm/x86.h
> @@ -83,6 +83,11 @@ static inline unsigned int __shrink_ple_window(unsigned int val,
>   void kvm_service_local_tlb_flush_requests(struct kvm_vcpu *vcpu);
>   int kvm_check_nested_events(struct kvm_vcpu *vcpu);
>   
> +static inline bool kvm_vcpu_has_run(struct kvm_vcpu *vcpu)
> +{
> +	return vcpu->arch.last_vmentry_cpu != -1;
> +}
> +
>   static inline bool kvm_is_exception_pending(struct kvm_vcpu *vcpu)
>   {
>   	return vcpu->arch.exception.pending ||


  reply	other threads:[~2023-02-14  6:35 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-10  0:31 [PATCH v2 00/21] KVM: x86: Disallow writes to feature MSRs post-KVM_RUN Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 01/21] KVM: x86: Rename kvm_init_msr_list() to clarify it inits multiple lists Sean Christopherson
2023-02-14  6:34   ` Xiaoyao Li
2023-02-10  0:31 ` [PATCH v2 02/21] KVM: x86: Add a helper to query whether or not a vCPU has ever run Sean Christopherson
2023-02-14  6:35   ` Xiaoyao Li [this message]
2023-02-10  0:31 ` [PATCH v2 03/21] KVM: x86: Add macros to track first...last VMX feature MSRs Sean Christopherson
2023-02-14 10:48   ` Like Xu
2023-02-14 18:51     ` Sean Christopherson
2023-02-15  3:20   ` Xiaoyao Li
2023-02-10  0:31 ` [PATCH v2 04/21] KVM: x86: Generate set of VMX feature MSRs using first/last definitions Sean Christopherson
2023-02-14  6:36   ` Xiaoyao Li
2023-02-10  0:31 ` [PATCH v2 05/21] KVM: x86: Disallow writes to immutable feature MSRs after KVM_RUN Sean Christopherson
2023-02-10 13:01   ` Yu Zhang
2023-02-10 16:31     ` Sean Christopherson
2023-02-14  6:39   ` Xiaoyao Li
2023-02-14 11:39   ` Like Xu
2023-02-15 22:36     ` Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 06/21] KVM: x86/pmu: WARN and bug the VM if PMU is refreshed after vCPU has run Sean Christopherson
2023-02-15 11:53   ` Like Xu
2023-02-15 15:20     ` Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 07/21] KVM: x86/pmu: Zero out LBR capabilities during PMU refresh Sean Christopherson
2023-02-15 12:00   ` Like Xu
2023-02-15 15:17     ` Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 08/21] KVM: selftests: Split PMU caps sub-tests to avoid writing MSR after KVM_RUN Sean Christopherson
2023-02-14  7:27   ` Like Xu
2023-02-14 17:42     ` Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 09/21] KVM: selftests: Move 0/initial value PERF_CAPS checks to dedicated sub-test Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 10/21] KVM: selftests: Assert that full-width PMC writes are supported if PDCM=1 Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 11/21] KVM: selftests: Print out failing MSR and value in vcpu_set_msr() Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 12/21] KVM: selftests: Verify KVM preserves userspace writes to "durable" MSRs Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 13/21] KVM: selftests: Drop now-redundant checks on PERF_CAPABILITIES writes Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 14/21] KVM: selftests: Test all fungible features in PERF_CAPABILITIES Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 15/21] KVM: selftests: Test all immutable non-format bits " Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 16/21] KVM: selftests: Expand negative testing of guest writes to PERF_CAPABILITIES Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 17/21] KVM: selftests: Test post-KVM_RUN " Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 18/21] KVM: selftests: Drop "all done!" printf() from PERF_CAPABILITIES test Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 19/21] KVM: selftests: Refactor LBR_FMT test to avoid use of separate macro Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 20/21] KVM: selftests: Add negative testcase for PEBS format in PERF_CAPABILITIES Sean Christopherson
2023-02-10  0:31 ` [PATCH v2 21/21] KVM: selftests: Verify LBRs are disabled if vPMU is disabled Sean Christopherson

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