diff mbox series

[2/3] KVM: SVM: Move svm_complete_interrupts() into svm_vcpu_run()

Message ID 1599620119-12971-1-git-send-email-wanpengli@tencent.com (mailing list archive)
State New, archived
Headers show
Series [1/3] KVM: SVM: Get rid of handle_fastpath_set_msr_irqoff() | expand

Commit Message

Wanpeng Li Sept. 9, 2020, 2:55 a.m. UTC
From: Wanpeng Li <wanpengli@tencent.com>

Moving svm_complete_interrupts() into svm_vcpu_run() which can align VMX 
and SVM with respect to completing interrupts.

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Paul K. <kronenpj@kronenpj.dyndns.org>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
 arch/x86/kvm/svm/svm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Vitaly Kuznetsov Sept. 9, 2020, 8:35 a.m. UTC | #1
Wanpeng Li <kernellwp@gmail.com> writes:

> From: Wanpeng Li <wanpengli@tencent.com>
>
> Moving svm_complete_interrupts() into svm_vcpu_run() which can align VMX 
> and SVM with respect to completing interrupts.
>
> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Cc: Paul K. <kronenpj@kronenpj.dyndns.org>
> Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> ---
>  arch/x86/kvm/svm/svm.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index c61bc3b..74bcf0a 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -2938,8 +2938,6 @@ static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
>  	if (npt_enabled)
>  		vcpu->arch.cr3 = svm->vmcb->save.cr3;
>  
> -	svm_complete_interrupts(svm);
> -
>  	if (is_guest_mode(vcpu)) {
>  		int vmexit;
>  
> @@ -3530,6 +3528,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
>  		     SVM_EXIT_EXCP_BASE + MC_VECTOR))
>  		svm_handle_mce(svm);
>  
> +	svm_complete_interrupts(svm);
> +
>  	vmcb_mark_all_clean(svm->vmcb);
>  	return exit_fastpath;
>  }

This seems to be the right thing to do, however, the amount of code
between kvm_x86_ops.run() and kvm_x86_ops.handle_exit() is non-trivial,
hope it won't blow up in testing...

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

One more thing:

VMX version does

        vmx_complete_interrupts(vmx);
        if (is_guest_mode(vcpu))
                return EXIT_FASTPATH_NONE;

and on SVM we analyze is_guest_mode() inside
svm_exit_handlers_fastpath() - should we also change that for
conformity?
Wanpeng Li Sept. 9, 2020, 8:47 a.m. UTC | #2
On Wed, 9 Sep 2020 at 16:36, Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
> Wanpeng Li <kernellwp@gmail.com> writes:
>
> > From: Wanpeng Li <wanpengli@tencent.com>
> >
> > Moving svm_complete_interrupts() into svm_vcpu_run() which can align VMX
> > and SVM with respect to completing interrupts.
> >
> > Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
> > Cc: Paul K. <kronenpj@kronenpj.dyndns.org>
> > Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> > ---
> >  arch/x86/kvm/svm/svm.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> > index c61bc3b..74bcf0a 100644
> > --- a/arch/x86/kvm/svm/svm.c
> > +++ b/arch/x86/kvm/svm/svm.c
> > @@ -2938,8 +2938,6 @@ static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
> >       if (npt_enabled)
> >               vcpu->arch.cr3 = svm->vmcb->save.cr3;
> >
> > -     svm_complete_interrupts(svm);
> > -
> >       if (is_guest_mode(vcpu)) {
> >               int vmexit;
> >
> > @@ -3530,6 +3528,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
> >                    SVM_EXIT_EXCP_BASE + MC_VECTOR))
> >               svm_handle_mce(svm);
> >
> > +     svm_complete_interrupts(svm);
> > +
> >       vmcb_mark_all_clean(svm->vmcb);
> >       return exit_fastpath;
> >  }
>
> This seems to be the right thing to do, however, the amount of code
> between kvm_x86_ops.run() and kvm_x86_ops.handle_exit() is non-trivial,
> hope it won't blow up in testing...
>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>
> One more thing:
>
> VMX version does
>
>         vmx_complete_interrupts(vmx);
>         if (is_guest_mode(vcpu))
>                 return EXIT_FASTPATH_NONE;
>
> and on SVM we analyze is_guest_mode() inside
> svm_exit_handlers_fastpath() - should we also change that for
> conformity?

Agreed, will do in v2.

    Wanpeng
Paolo Bonzini Sept. 12, 2020, 6:20 a.m. UTC | #3
On 09/09/20 10:47, Wanpeng Li wrote:
>> One more thing:
>>
>> VMX version does
>>
>>         vmx_complete_interrupts(vmx);
>>         if (is_guest_mode(vcpu))
>>                 return EXIT_FASTPATH_NONE;
>>
>> and on SVM we analyze is_guest_mode() inside
>> svm_exit_handlers_fastpath() - should we also change that for
>> conformity?
> 
> Agreed, will do in v2.

Please just send an incremental patch.  Thanks!

Paolo
Wanpeng Li Sept. 14, 2020, 6:56 a.m. UTC | #4
On Sat, 12 Sep 2020 at 14:20, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 09/09/20 10:47, Wanpeng Li wrote:
> >> One more thing:
> >>
> >> VMX version does
> >>
> >>         vmx_complete_interrupts(vmx);
> >>         if (is_guest_mode(vcpu))
> >>                 return EXIT_FASTPATH_NONE;
> >>
> >> and on SVM we analyze is_guest_mode() inside
> >> svm_exit_handlers_fastpath() - should we also change that for
> >> conformity?
> >
> > Agreed, will do in v2.
>
> Please just send an incremental patch.  Thanks!

Just sent out a patch to do it. :)

    Wanpeng
diff mbox series

Patch

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index c61bc3b..74bcf0a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2938,8 +2938,6 @@  static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
 	if (npt_enabled)
 		vcpu->arch.cr3 = svm->vmcb->save.cr3;
 
-	svm_complete_interrupts(svm);
-
 	if (is_guest_mode(vcpu)) {
 		int vmexit;
 
@@ -3530,6 +3528,8 @@  static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 		     SVM_EXIT_EXCP_BASE + MC_VECTOR))
 		svm_handle_mce(svm);
 
+	svm_complete_interrupts(svm);
+
 	vmcb_mark_all_clean(svm->vmcb);
 	return exit_fastpath;
 }