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 <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 54f7ea6..99d118f 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 */