From: Maxim Levitsky <mlevitsk@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/9] KVM: x86: Avoid double CPUID lookup when updating MWAIT at runtime
Date: Sun, 19 Nov 2023 19:33:01 +0200 [thread overview]
Message-ID: <8c518aae88a6db2347813985ea4e7c2ccee585da.camel@redhat.com> (raw)
In-Reply-To: <20231110235528.1561679-5-seanjc@google.com>
On Fri, 2023-11-10 at 15:55 -0800, Sean Christopherson wrote:
> Move the handling of X86_FEATURE_MWAIT during CPUID runtime updates to
> utilize the lookup done for other CPUID.0x1 features.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> arch/x86/kvm/cpuid.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 5cf3d697ecb3..6777780be6ae 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -276,6 +276,11 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
>
> cpuid_entry_change(best, X86_FEATURE_APIC,
> vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
> +
> + if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT))
> + cpuid_entry_change(best, X86_FEATURE_MWAIT,
> + vcpu->arch.ia32_misc_enable_msr &
> + MSR_IA32_MISC_ENABLE_MWAIT);
> }
>
> best = cpuid_entry2_find(entries, nent, 7, 0);
> @@ -296,14 +301,6 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e
> if (kvm_hlt_in_guest(vcpu->kvm) && best &&
> (best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
> best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
> -
> - if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
> - best = cpuid_entry2_find(entries, nent, 0x1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
> - if (best)
> - cpuid_entry_change(best, X86_FEATURE_MWAIT,
> - vcpu->arch.ia32_misc_enable_msr &
> - MSR_IA32_MISC_ENABLE_MWAIT);
> - }
> }
>
> void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Best regards,
Maxim Levitsky
next prev parent reply other threads:[~2023-11-19 17:33 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-10 23:55 [PATCH 0/9] KVM: x86: Replace governed features with guest cpu_caps Sean Christopherson
2023-11-10 23:55 ` [PATCH 1/9] KVM: x86: Rename "governed features" helpers to use "guest_cpu_cap" Sean Christopherson
2023-11-19 17:08 ` Maxim Levitsky
2023-11-21 3:20 ` Chao Gao
2023-11-10 23:55 ` [PATCH 2/9] KVM: x86: Replace guts of "goverened" features with comprehensive cpu_caps Sean Christopherson
2023-11-14 9:12 ` Binbin Wu
2023-11-19 17:22 ` Maxim Levitsky
2023-11-28 1:24 ` Sean Christopherson
2023-11-10 23:55 ` [PATCH 3/9] KVM: x86: Initialize guest cpu_caps based on guest CPUID Sean Christopherson
2023-11-16 3:16 ` Yang, Weijiang
2023-11-16 22:29 ` Sean Christopherson
2023-11-17 8:33 ` Yang, Weijiang
2023-11-21 3:10 ` Yuan Yao
2023-11-19 17:32 ` Maxim Levitsky
2023-12-01 1:51 ` Sean Christopherson
2023-12-21 16:59 ` Maxim Levitsky
2024-01-05 2:13 ` Sean Christopherson
2024-01-12 0:44 ` Sean Christopherson
2023-11-10 23:55 ` [PATCH 4/9] KVM: x86: Avoid double CPUID lookup when updating MWAIT at runtime Sean Christopherson
2023-11-19 17:33 ` Maxim Levitsky [this message]
2023-11-10 23:55 ` [PATCH 5/9] KVM: x86: Drop unnecessary check that cpuid_entry2_find() returns right leaf Sean Christopherson
2023-11-19 17:33 ` Maxim Levitsky
2023-11-10 23:55 ` [PATCH 6/9] KVM: x86: Update guest cpu_caps at runtime for dynamic CPUID-based features Sean Christopherson
2023-11-13 8:03 ` Robert Hoo
2023-11-14 13:48 ` Sean Christopherson
2023-11-15 1:59 ` Robert Hoo
2023-11-15 15:09 ` Sean Christopherson
2023-11-17 1:28 ` Robert Hoo
2023-11-16 2:24 ` Yang, Weijiang
2023-11-16 22:19 ` Sean Christopherson
2023-11-19 17:35 ` Maxim Levitsky
2023-11-24 6:33 ` Xu Yilun
2023-11-28 0:43 ` Sean Christopherson
2023-11-28 5:13 ` Xu Yilun
2023-11-10 23:55 ` [PATCH 7/9] KVM: x86: Shuffle code to prepare for dropping guest_cpuid_has() Sean Christopherson
2023-11-19 17:35 ` Maxim Levitsky
2023-11-10 23:55 ` [PATCH 8/9] KVM: x86: Replace all guest CPUID feature queries with cpu_caps check Sean Christopherson
2023-11-19 17:35 ` Maxim Levitsky
2023-11-10 23:55 ` [PATCH 9/9] KVM: x86: Restrict XSAVE in cpu_caps based on KVM capabilities Sean Christopherson
2023-11-19 17:36 ` Maxim Levitsky
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