diff mbox series

[RESEND,3/3] KVM: SVM: Reenable handle_fastpath_set_msr_irqoff() after complete_interrupts()

Message ID 1599620237-13156-3-git-send-email-wanpengli@tencent.com (mailing list archive)
State New, archived
Headers show
Series [RESEND,1/3] KVM: SVM: Get rid of handle_fastpath_set_msr_irqoff() | expand

Commit Message

Wanpeng Li Sept. 9, 2020, 2:57 a.m. UTC 
From: Wanpeng Li <wanpengli@tencent.com>

Moving the call to svm_exit_handlers_fastpath() after svm_complete_interrupts() 
since svm_complete_interrupts() consumes rip and reenable the function 
handle_fastpath_set_msr_irqoff() call in svm_exit_handlers_fastpath().

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 | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Paolo Bonzini Sept. 12, 2020, 6:15 a.m. UTC | #1 
The overall patch is fairly simple:

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 03dd7bac8034..d6ce75e107c0 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;

@@ -3504,7 +3502,6 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct
kvm_vcpu *vcpu)
 	stgi();

 	/* Any pending NMI will happen here */
-	exit_fastpath = svm_exit_handlers_fastpath(vcpu);

 	if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI))
 		kvm_after_interrupt(&svm->vcpu);
@@ -3537,6 +3534,9 @@ 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);
+	exit_fastpath = svm_exit_handlers_fastpath(vcpu);
+
 	vmcb_mark_all_clean(svm->vmcb);
 	return exit_fastpath;
 }

so I will just squash everything.

Paolo
Sean Christopherson Sept. 14, 2020, 3:48 p.m. UTC | #2 
On Sat, Sep 12, 2020 at 08:15:46AM +0200, Paolo Bonzini wrote:
> The overall patch is fairly simple:
> 
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 03dd7bac8034..d6ce75e107c0 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;
> 
> @@ -3504,7 +3502,6 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct
> kvm_vcpu *vcpu)
>  	stgi();
> 
>  	/* Any pending NMI will happen here */
> -	exit_fastpath = svm_exit_handlers_fastpath(vcpu);
> 
>  	if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI))
>  		kvm_after_interrupt(&svm->vcpu);
> @@ -3537,6 +3534,9 @@ 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);
> +	exit_fastpath = svm_exit_handlers_fastpath(vcpu);
> +
>  	vmcb_mark_all_clean(svm->vmcb);
>  	return exit_fastpath;
>  }
> 
> so I will just squash everything.

The thought behind the multi-patch series was to allow automatically applying
the fix to the 5.8 stable tree without having to take on the risk of moving
svm_complete_interrupts().
diff mbox series

Patch

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 74bcf0a..ac819f0 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3347,6 +3347,11 @@  static void svm_cancel_injection(struct kvm_vcpu *vcpu)
 
 static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
 {
+	if (!is_guest_mode(vcpu) &&
+	    to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR &&
+	    to_svm(vcpu)->vmcb->control.exit_info_1)
+		return handle_fastpath_set_msr_irqoff(vcpu);
+
 	return EXIT_FASTPATH_NONE;
 }
 
@@ -3495,7 +3500,6 @@  static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 	stgi();
 
 	/* Any pending NMI will happen here */
-	exit_fastpath = svm_exit_handlers_fastpath(vcpu);
 
 	if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI))
 		kvm_after_interrupt(&svm->vcpu);
@@ -3529,6 +3533,7 @@  static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 		svm_handle_mce(svm);
 
 	svm_complete_interrupts(svm);
+	exit_fastpath = svm_exit_handlers_fastpath(vcpu);
 
 	vmcb_mark_all_clean(svm->vmcb);
 	return exit_fastpath;