KVM: x86: Move delivery of non-APICv interrupt into vendor code

Handle non-APICv interrupt delivery in vendor code, even though it means
VMX and SVM will temporarily have duplicate code.  SVM's AVIC has a race
condition that requires KVM to fall back to legacy interrupt injection
_after_ the interrupt has been logged in the vIRR, i.e. to fix the race,
SVM will need to open code the full flow anyways[*].  Refactor the code
so that the SVM bug without introducing other issues, e.g. SVM would
return "success" and thus invoke trace_kvm_apicv_accept_irq() even when
delivery through the AVIC failed, and to opportunistically prepare for
using KVM_X86_OP to fill each vendor's kvm_x86_ops struct, which will
rely on the vendor function matching the kvm_x86_op pointer name.

No functional change intended.

[*] https://lore.kernel.org/all/20211213104634.199141-4-mlevitsk@redhat.com

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220128005208.4008533-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 631d504..d39e0de 100644 (file)
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -82,7 +82,7 @@ KVM_X86_OP_NULL(guest_apic_has_interrupt)
 KVM_X86_OP(load_eoi_exitmap)
 KVM_X86_OP(set_virtual_apic_mode)
 KVM_X86_OP_NULL(set_apic_access_page_addr)
-KVM_X86_OP(deliver_posted_interrupt)
+KVM_X86_OP(deliver_interrupt)
 KVM_X86_OP_NULL(sync_pir_to_irr)
 KVM_X86_OP(set_tss_addr)
 KVM_X86_OP(set_identity_map_addr)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index efee29d..80e2855 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1409,7 +1409,8 @@ struct kvm_x86_ops {
        void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
        void (*set_virtual_apic_mode)(struct kvm_vcpu *vcpu);
        void (*set_apic_access_page_addr)(struct kvm_vcpu *vcpu);
-       int (*deliver_posted_interrupt)(struct kvm_vcpu *vcpu, int vector);
+       void (*deliver_interrupt)(struct kvm_lapic *apic, int delivery_mode,
+                                 int trig_mode, int vector);
        int (*sync_pir_to_irr)(struct kvm_vcpu *vcpu);
        int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
        int (*set_identity_map_addr)(struct kvm *kvm, u64 ident_addr);

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 4662469..d7e6fde 100644 (file)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1096,14 +1096,8 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
                                                       apic->regs + APIC_TMR);
                }
 
-               if (static_call(kvm_x86_deliver_posted_interrupt)(vcpu, vector)) {
-                       kvm_lapic_set_irr(vector, apic);
-                       kvm_make_request(KVM_REQ_EVENT, vcpu);
-                       kvm_vcpu_kick(vcpu);
-               } else {
-                       trace_kvm_apicv_accept_irq(vcpu->vcpu_id, delivery_mode,
-                                                  trig_mode, vector);
-               }
+               static_call(kvm_x86_deliver_interrupt)(apic, delivery_mode,
+                                                      trig_mode, vector);
                break;
 
        case APIC_DM_REMRD:

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 9cef8e4..5772dd6 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3291,6 +3291,21 @@ static void svm_set_irq(struct kvm_vcpu *vcpu)
                SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR;
 }
 
+static void svm_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,
+                                 int trig_mode, int vector)
+{
+       struct kvm_vcpu *vcpu = apic->vcpu;
+
+       if (svm_deliver_avic_intr(vcpu, vector)) {
+               kvm_lapic_set_irr(vector, apic);
+               kvm_make_request(KVM_REQ_EVENT, vcpu);
+               kvm_vcpu_kick(vcpu);
+       } else {
+               trace_kvm_apicv_accept_irq(vcpu->vcpu_id, delivery_mode,
+                                          trig_mode, vector);
+       }
+}
+
 static void svm_update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
 {
        struct vcpu_svm *svm = to_svm(vcpu);
@@ -4545,7 +4560,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
        .pmu_ops = &amd_pmu_ops,
        .nested_ops = &svm_nested_ops,
 
-       .deliver_posted_interrupt = svm_deliver_avic_intr,
+       .deliver_interrupt = svm_deliver_interrupt,
        .dy_apicv_has_pending_interrupt = svm_dy_apicv_has_pending_interrupt,
        .update_pi_irte = svm_update_pi_irte,
        .setup_mce = svm_setup_mce,

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b1165bb..3c0ba5b 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4041,6 +4041,21 @@ static int vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
        return 0;
 }
 
+static void vmx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,
+                                 int trig_mode, int vector)
+{
+       struct kvm_vcpu *vcpu = apic->vcpu;
+
+       if (vmx_deliver_posted_interrupt(vcpu, vector)) {
+               kvm_lapic_set_irr(vector, apic);
+               kvm_make_request(KVM_REQ_EVENT, vcpu);
+               kvm_vcpu_kick(vcpu);
+       } else {
+               trace_kvm_apicv_accept_irq(vcpu->vcpu_id, delivery_mode,
+                                          trig_mode, vector);
+       }
+}
+
 /*
  * Set up the vmcs's constant host-state fields, i.e., host-state fields that
  * will not change in the lifetime of the guest.
@@ -7766,7 +7781,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
        .hwapic_isr_update = vmx_hwapic_isr_update,
        .guest_apic_has_interrupt = vmx_guest_apic_has_interrupt,
        .sync_pir_to_irr = vmx_sync_pir_to_irr,
-       .deliver_posted_interrupt = vmx_deliver_posted_interrupt,
+       .deliver_interrupt = vmx_deliver_interrupt,
        .dy_apicv_has_pending_interrupt = pi_has_pending_interrupt,
 
        .set_tss_addr = vmx_set_tss_addr,