linux-kernel - Re: [PATCH 21/43] KVM: nVMX: Don't reread VMCS-agnostic state when switching VMCS

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Message-ID: <20190614162532.GG12191@linux.intel.com>
Date:   Fri, 14 Jun 2019 09:25:39 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        vkuznets@...hat.com
Subject: Re: [PATCH 21/43] KVM: nVMX: Don't reread VMCS-agnostic state when
 switching VMCS

On Thu, Jun 13, 2019 at 07:03:07PM +0200, Paolo Bonzini wrote:
> From: Sean Christopherson <sean.j.christopherson@...el.com>
> 
> When switching between vmcs01 and vmcs02, there is no need to update
> state tracking for values that aren't tied to any particular VMCS as
> the per-vCPU values are already up-to-date (vmx_switch_vmcs() can only
> be called when the vCPU is loaded).
> 
> Avoiding the update eliminates a RDMSR, and potentially a RDPKRU and
> posted-interrupt updated (cmpxchg64() and more).

Another typo, s/updated/update.

> 
> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
> Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
> ---