From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Wanpeng Li <kernellwp@gmail.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Wanpeng Li <wanpeng.li@hotmail.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Wincy Van <fanwenyi0529@gmail.com>,
Yang Zhang <yang.zhang.wz@gmail.com>
Subject: Re: [PATCH v4] KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactive
Date: Fri, 23 Sep 2016 01:13:50 +0200 [thread overview]
Message-ID: <20160922231350.GB7554@potion> (raw)
In-Reply-To: <1474501405-8312-1-git-send-email-wanpeng.li@hotmail.com>
2016-09-22 07:43+0800, Wanpeng Li:
> From: Wanpeng Li <wanpeng.li@hotmail.com>
>
> I observed that kvmvapic(to optimize flexpriority=N or AMD) is used
> to boost TPR access when testing kvm-unit-test/eventinj.flat tpr case
> on my haswell desktop (w/ flexpriority, w/o APICv). Commit (8d14695f9542
> x86, apicv: add virtual x2apic support) disable virtual x2apic mode
> completely if w/o APICv, and the author also told me that windows guest
> can't enter into x2apic mode when he developed the APICv feature several
> years ago. However, it is not truth currently, Interrupt Remapping and
> vIOMMU is added to qemu and the developers from Intel test windows 8 can
> work in x2apic mode w/ Interrupt Remapping enabled recently.
>
> This patch enables TPR shadow for virtual x2apic mode to boost
> windows guest in x2apic mode even if w/o APICv.
>
> Can pass the kvm-unit-test.
>
> Suggested-by: Radim Krčmář <rkrcmar@redhat.com>
> Suggested-by: Wincy Van <fanwenyi0529@gmail.com>
> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Cc: Wincy Van <fanwenyi0529@gmail.com>
> Cc: Yang Zhang <yang.zhang.wz@gmail.com>
> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
Applied to kvm/queue, thanks.
prev parent reply other threads:[~2016-09-22 23:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-21 23:43 [PATCH v4] KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactive Wanpeng Li
2016-09-22 23:13 ` Radim Krčmář [this message]
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