> -----Original Message----- > From: linux-kernel-owner@xxxxxxxxxxxxxxx > [mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] On Behalf Of Paolo Bonzini > Sent: Wednesday, August 05, 2015 11:24 PM > To: linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx > Cc: Steve Rutherford; rkrcmar@xxxxxxxxxx > Subject: [PATCH 5/9] KVM: x86: unify handling of interrupt window > > The interrupt window is currently checked twice, once in vmx.c/svm.c and > once in dm_request_for_irq_injection. The only difference is the extra > check for kvm_arch_interrupt_allowed in dm_request_for_irq_injection, > and the different return value (EINTR/KVM_EXIT_INTR for vmx.c/svm.c vs. > 0/KVM_EXIT_IRQ_WINDOW_OPEN for dm_request_for_irq_injection). > > However, dm_request_for_irq_injection is basically dead code! Revive it > by removing the checks in vmx.c and svm.c's vmexit handlers, and > fixing the returned values for the dm_request_for_irq_injection case. > > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > --- > arch/x86/kvm/svm.c | 13 ------------- > arch/x86/kvm/vmx.c | 11 ----------- > arch/x86/kvm/x86.c | 4 ++-- > 3 files changed, 2 insertions(+), 26 deletions(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 222439fd73d4..189e46479dd5 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -3396,24 +3396,11 @@ static int msr_interception(struct vcpu_svm > *svm) > > static int interrupt_window_interception(struct vcpu_svm *svm) > { > - struct kvm_run *kvm_run = svm->vcpu.run; > - > kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); > svm_clear_vintr(svm); > svm->vmcb->control.int_ctl &= ~V_IRQ_MASK; > mark_dirty(svm->vmcb, VMCB_INTR); > ++svm->vcpu.stat.irq_window_exits; > - /* > - * If the user space waits to inject interrupts, exit as soon as > - * possible > - */ > - if (!lapic_in_kernel(&svm->vcpu) && > - kvm_run->request_interrupt_window && > - !kvm_cpu_has_interrupt(&svm->vcpu)) { > - kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; > - return 0; > - } > - > return 1; > } > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index ef15dc72284b..4cf25b90dbe0 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -5524,17 +5524,6 @@ static int handle_interrupt_window(struct > kvm_vcpu *vcpu) > kvm_make_request(KVM_REQ_EVENT, vcpu); > > ++vcpu->stat.irq_window_exits; > - > - /* > - * If the user space waits to inject interrupts, exit as soon as > - * possible > - */ > - if (!lapic_in_kernel(vcpu) && > - vcpu->run->request_interrupt_window && > - !kvm_cpu_has_interrupt(vcpu)) { > - vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; > - return 0; > - } > return 1; > } Is it possible to adjust the code here and remove the later checking in x86.c? In that case, we can avoid calling dm_request_for_irq_injection(vcpu) for VM exit. Basically dm_request_for_irq_injection() did the following checks: - The same as in handle_interrupt_window() below: if (!irqchip_in_kernel(vcpu->kvm) && vcpu->run->request_interrupt_window && !kvm_cpu_has_interrupt(vcpu)) - kvm_arch_interrupt_allowed(vcpu), in which, most of the conditions are guaranteed by interrupt window exits, the only one I am not sure how to handle is ' to_vmx(vcpu)->nested.nested_run_pending'. Thanks, Feng > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index daa6d4fe97fe..62362fed4169 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6475,8 +6475,8 @@ static int vcpu_run(struct kvm_vcpu *vcpu) > kvm_inject_pending_timer_irqs(vcpu); > > if (dm_request_for_irq_injection(vcpu)) { > - r = -EINTR; > - vcpu->run->exit_reason = KVM_EXIT_INTR; > + r = 0; > + vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; > ++vcpu->stat.request_irq_exits; > break; > } > -- > 1.8.3.1 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
