From: Maxim Levitsky <mlevitsk@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] KVM: x86: Identify vCPU0 by its vcpu_idx instead of walking vCPUs array
Date: Sun, 12 Sep 2021 13:52:43 +0300 [thread overview]
Message-ID: <71a6464fa0bca675e079f6171296ff5f63cab05c.camel@redhat.com> (raw)
In-Reply-To: <20210910183220.2397812-3-seanjc@google.com>
On Fri, 2021-09-10 at 11:32 -0700, Sean Christopherson wrote:
> Use vcpu_idx to identify vCPU0 when updating HyperV's TSC page, which is
> shared by all vCPUs and "owned" by vCPU0 (because vCPU0 is the only vCPU
> that's guaranteed to exist). Using kvm_get_vcpu() to find vCPU works,
> but it's a rather odd and suboptimal method to check the index of a given
> vCPU.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> arch/x86/kvm/x86.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 86539c1686fa..6ab851df08d1 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2969,7 +2969,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
> offsetof(struct compat_vcpu_info, time));
> if (vcpu->xen.vcpu_time_info_set)
> kvm_setup_pvclock_page(v, &vcpu->xen.vcpu_time_info_cache, 0);
> - if (v == kvm_get_vcpu(v->kvm, 0))
> + if (!v->vcpu_idx)
> kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);
> return 0;
> }
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Best regards,
Maxim Levitsky
next prev parent reply other threads:[~2021-09-12 10:52 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-10 18:32 [PATCH 0/2] KVM: x86: vcpu_idx related cleanups Sean Christopherson
2021-09-10 18:32 ` [PATCH 1/2] KVM: x86: Query vcpu->vcpu_idx directly and drop its accessor Sean Christopherson
2021-09-12 10:49 ` Maxim Levitsky
2021-09-13 7:02 ` Vitaly Kuznetsov
2021-09-10 18:32 ` [PATCH 2/2] KVM: x86: Identify vCPU0 by its vcpu_idx instead of walking vCPUs array Sean Christopherson
2021-09-10 21:46 ` Jim Mattson
2021-09-12 10:52 ` Maxim Levitsky [this message]
2021-09-13 7:07 ` Vitaly Kuznetsov
2021-09-20 14:57 ` Sean Christopherson
2021-09-22 7:41 ` Paolo Bonzini
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