From: Marcelo Tosatti <mtosatti@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: kvm <kvm@vger.kernel.org>
Subject: Re: KVM: VMX: remove GUEST_CR3 write from vmx_vcpu_run
Date: Tue, 20 Oct 2009 11:59:28 -0200 [thread overview]
Message-ID: <20091020135928.GA6992@amt.cnet> (raw)
In-Reply-To: <4ADDB7CC.8040808@redhat.com>
On Tue, Oct 20, 2009 at 10:14:52PM +0900, Avi Kivity wrote:
> On 10/20/2009 09:37 PM, Marcelo Tosatti wrote:
>> GUEST_CR3 is updated via kvm_set_cr3 whenever CR3 value
>> changes.
>>
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index 364263a..325075f 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -3638,10 +3638,9 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
>> {
>> struct vcpu_vmx *vmx = to_vmx(vcpu);
>>
>> - if (enable_ept&& is_paging(vcpu)) {
>> - vmcs_writel(GUEST_CR3, vcpu->arch.cr3);
>> + if (enable_ept&& is_paging(vcpu))
>> ept_load_pdptrs(vcpu);
>> - }
>> +
>> /* Record the guest's net vcpu time for enforced NMI injections. */
>> if (unlikely(!cpu_has_virtual_nmis()&& vmx->soft_vnmi_blocked))
>> vmx->entry_time = ktime_get();
>>
>
> Nice. Any reason why ept_load_pdptrs() couldn't go the same way?
Its already protected by VCPU_EXREG_PDPTR caching, so it does not buy
much.
The advantage would symmetry to cr3.
next prev parent reply other threads:[~2009-10-20 17:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-20 12:37 KVM: VMX: remove GUEST_CR3 write from vmx_vcpu_run Marcelo Tosatti
2009-10-20 13:14 ` Avi Kivity
2009-10-20 13:59 ` Marcelo Tosatti [this message]
2009-10-22 7:06 ` Avi Kivity
2009-10-22 7:35 ` Sheng Yang
2009-10-22 7:48 ` Avi Kivity
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