* [PATCH] do not call gva_to_gpa on physical address
@ 2010-07-14 15:38 Gleb Natapov
2010-07-14 15:44 ` Avi Kivity
0 siblings, 1 reply; 4+ messages in thread
From: Gleb Natapov @ 2010-07-14 15:38 UTC (permalink / raw)
To: mtosatti, avi; +Cc: kvm
When tdp is enabled cr2 passed to emulator is pga not gva, so no need to
call gva_to_gpa on it.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fb08316..721bf0a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3944,10 +3944,13 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)
if (kvm_mmu_unprotect_page_virt(vcpu, gva))
return true;
- gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
+ if (!tdp_enabled) {
+ gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
- if (gpa == UNMAPPED_GVA)
- return true; /* let cpu generate fault */
+ if (gpa == UNMAPPED_GVA)
+ return true; /* let cpu generate fault */
+ } else
+ gpa = gva;
if (!kvm_is_error_hva(gfn_to_hva(vcpu->kvm, gpa >> PAGE_SHIFT)))
return true;
--
Gleb.
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] do not call gva_to_gpa on physical address
2010-07-14 15:38 [PATCH] do not call gva_to_gpa on physical address Gleb Natapov
@ 2010-07-14 15:44 ` Avi Kivity
2010-07-14 15:52 ` Gleb Natapov
0 siblings, 1 reply; 4+ messages in thread
From: Avi Kivity @ 2010-07-14 15:44 UTC (permalink / raw)
To: Gleb Natapov; +Cc: mtosatti, kvm
On 07/14/2010 06:38 PM, Gleb Natapov wrote:
> When tdp is enabled cr2 passed to emulator is pga not gva, so no need to
> call gva_to_gpa on it.
>
> Signed-off-by: Gleb Natapov<gleb@redhat.com>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index fb08316..721bf0a 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3944,10 +3944,13 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)
> if (kvm_mmu_unprotect_page_virt(vcpu, gva))
> return true;
>
> - gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
> + if (!tdp_enabled) {
> + gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
>
> - if (gpa == UNMAPPED_GVA)
> - return true; /* let cpu generate fault */
> + if (gpa == UNMAPPED_GVA)
> + return true; /* let cpu generate fault */
> + } else
> + gpa = gva;
>
> if (!kvm_is_error_hva(gfn_to_hva(vcpu->kvm, gpa>> PAGE_SHIFT)))
> return true;
>
Why not
if (tdp_enabled)
return false;
at the top? Is there any reason ever to reexecute an instruction with
tdp enabled?
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] do not call gva_to_gpa on physical address
2010-07-14 15:44 ` Avi Kivity
@ 2010-07-14 15:52 ` Gleb Natapov
2010-07-14 15:55 ` Avi Kivity
0 siblings, 1 reply; 4+ messages in thread
From: Gleb Natapov @ 2010-07-14 15:52 UTC (permalink / raw)
To: Avi Kivity; +Cc: mtosatti, kvm
On Wed, Jul 14, 2010 at 06:44:15PM +0300, Avi Kivity wrote:
> On 07/14/2010 06:38 PM, Gleb Natapov wrote:
> >When tdp is enabled cr2 passed to emulator is pga not gva, so no need to
> >call gva_to_gpa on it.
> >
> >Signed-off-by: Gleb Natapov<gleb@redhat.com>
> >diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> >index fb08316..721bf0a 100644
> >--- a/arch/x86/kvm/x86.c
> >+++ b/arch/x86/kvm/x86.c
> >@@ -3944,10 +3944,13 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)
> > if (kvm_mmu_unprotect_page_virt(vcpu, gva))
> > return true;
> >
> >- gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
> >+ if (!tdp_enabled) {
> >+ gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
> >
> >- if (gpa == UNMAPPED_GVA)
> >- return true; /* let cpu generate fault */
> >+ if (gpa == UNMAPPED_GVA)
> >+ return true; /* let cpu generate fault */
> >+ } else
> >+ gpa = gva;
> >
> > if (!kvm_is_error_hva(gfn_to_hva(vcpu->kvm, gpa>> PAGE_SHIFT)))
> > return true;
>
> Why not
>
> if (tdp_enabled)
> return false;
>
> at the top? Is there any reason ever to reexecute an instruction
> with tdp enabled?
>
Can't think of one now. If in the future we will shadow some other data
structures in the guest except page tables (nested vmx/svm?) there may
be the reason.
--
Gleb.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] do not call gva_to_gpa on physical address
2010-07-14 15:52 ` Gleb Natapov
@ 2010-07-14 15:55 ` Avi Kivity
0 siblings, 0 replies; 4+ messages in thread
From: Avi Kivity @ 2010-07-14 15:55 UTC (permalink / raw)
To: Gleb Natapov; +Cc: mtosatti, kvm
On 07/14/2010 06:52 PM, Gleb Natapov wrote:
>
>> Why not
>>
>> if (tdp_enabled)
>> return false;
>>
>> at the top? Is there any reason ever to reexecute an instruction
>> with tdp enabled?
>>
>>
> Can't think of one now. If in the future we will shadow some other data
> structures in the guest except page tables (nested vmx/svm?) there may
> be the reason.
>
Sure, we'll adjust it then.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2010-07-14 15:38 [PATCH] do not call gva_to_gpa on physical address Gleb Natapov
2010-07-14 15:44 ` Avi Kivity
2010-07-14 15:52 ` Gleb Natapov
2010-07-14 15:55 ` Avi Kivity
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