From ffdf7f9e80ac1b6fea3bc6a65ea1f264bc226eab Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 22 May 2020 12:18:27 -0400 Subject: [PATCH] KVM: nSVM: extract svm_set_gif Extract the code that is needed to implement CLGI and STGI, so that we can run it from VMRUN and vmexit (and in the future, KVM_SET_NESTED_STATE). Skip the request for KVM_REQ_EVENT unless needed, subsuming the evaluate_pending_interrupts optimization that is found in enter_svm_guest_mode. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/irq.c | 1 + arch/x86/kvm/svm/nested.c | 22 ++------------------ arch/x86/kvm/svm/svm.c | 51 +++++++++++++++++++++++++++++++---------------- arch/x86/kvm/svm/svm.h | 1 + 4 files changed, 38 insertions(+), 37 deletions(-) diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index 54f7ea68..99d118f 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -83,6 +83,7 @@ int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ } +EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr); /* * check if there is pending interrupt without diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 921466e..7e4a506 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -333,10 +333,6 @@ static void nested_prepare_vmcb_control(struct vcpu_svm *svm) void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, struct vmcb *nested_vmcb) { - bool evaluate_pending_interrupts = - is_intercept(svm, INTERCEPT_VINTR) || - is_intercept(svm, INTERCEPT_IRET); - svm->nested.vmcb = vmcb_gpa; if (kvm_get_rflags(&svm->vcpu) & X86_EFLAGS_IF) svm->vcpu.arch.hflags |= HF_HIF_MASK; @@ -347,21 +343,7 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, nested_prepare_vmcb_save(svm, nested_vmcb); nested_prepare_vmcb_control(svm); - /* - * If L1 had a pending IRQ/NMI before executing VMRUN, - * which wasn't delivered because it was disallowed (e.g. - * interrupts disabled), L0 needs to evaluate if this pending - * event should cause an exit from L2 to L1 or be delivered - * directly to L2. - * - * Usually this would be handled by the processor noticing an - * IRQ/NMI window request. However, VMRUN can unblock interrupts - * by implicitly setting GIF, so force L0 to perform pending event - * evaluation by requesting a KVM_REQ_EVENT. - */ - enable_gif(svm); - if (unlikely(evaluate_pending_interrupts)) - kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); + svm_set_gif(svm, true); } int nested_svm_vmrun(struct vcpu_svm *svm) @@ -505,7 +487,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm) svm->vcpu.arch.mp_state = KVM_MP_STATE_RUNNABLE; /* Give the current vmcb to the guest */ - disable_gif(svm); + svm_set_gif(svm, false); nested_vmcb->save.es = vmcb->save.es; nested_vmcb->save.cs = vmcb->save.cs; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 7383f82..e48e417 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1981,6 +1981,38 @@ static int vmrun_interception(struct vcpu_svm *svm) return nested_svm_vmrun(svm); } +void svm_set_gif(struct vcpu_svm *svm, bool value) +{ + if (value) { + /* + * If VGIF is enabled, the STGI intercept is only added to + * detect the opening of the SMI/NMI window; remove it now. + * Likewise, clear the VINTR intercept, we will set it + * again while processing KVM_REQ_EVENT if needed. + */ + if (vgif_enabled(svm)) + clr_intercept(svm, INTERCEPT_STGI); + if (is_intercept(svm, SVM_EXIT_VINTR)) + svm_clear_vintr(svm); + + enable_gif(svm); + if (svm->vcpu.arch.smi_pending || + svm->vcpu.arch.nmi_pending || + kvm_cpu_has_injectable_intr(&svm->vcpu)) + kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); + } else { + disable_gif(svm); + + /* + * After a CLGI no interrupts should come. But if vGIF is + * in use, we still rely on the VINTR intercept (rather than + * STGI) to detect an open interrupt window. + */ + if (!vgif_enabled(svm)) + svm_clear_vintr(svm); + } +} + static int stgi_interception(struct vcpu_svm *svm) { int ret; @@ -1988,18 +2020,8 @@ static int stgi_interception(struct vcpu_svm *svm) if (nested_svm_check_permissions(svm)) return 1; - /* - * If VGIF is enabled, the STGI intercept is only added to - * detect the opening of the SMI/NMI window; remove it now. - */ - if (vgif_enabled(svm)) - clr_intercept(svm, INTERCEPT_STGI); - ret = kvm_skip_emulated_instruction(&svm->vcpu); - kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); - - enable_gif(svm); - + svm_set_gif(svm, true); return ret; } @@ -2011,12 +2033,7 @@ static int clgi_interception(struct vcpu_svm *svm) return 1; ret = kvm_skip_emulated_instruction(&svm->vcpu); - - disable_gif(svm); - - /* After a CLGI no interrupts should come */ - svm_clear_vintr(svm); - + svm_set_gif(svm, false); return ret; } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 7e79f0a..10b7b55 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -357,6 +357,7 @@ void disable_nmi_singlestep(struct vcpu_svm *svm); bool svm_smi_blocked(struct kvm_vcpu *vcpu); bool svm_nmi_blocked(struct kvm_vcpu *vcpu); bool svm_interrupt_blocked(struct kvm_vcpu *vcpu); +void svm_set_gif(struct vcpu_svm *svm, bool value); /* nested.c */ -- 2.7.4