KVM: VMX: refactor IRQ and NMI window enabling

do_interrupt_requests and vmx_intr_assist go different way for
achieving the same: enabling the nmi/irq window start notification.
Unify their code over enable_{irq|nmi}_window, get rid of a redundant
call to enable_intr_window instead of direct enable_nmi_window
invocation and unroll enable_intr_window for both in-kernel and user
space irq injection accordingly.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 32 insertions, 46 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index f0866e1d20ee..440f56cd4bdd 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2389,30 +2389,42 @@ static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
         kvm_queue_interrupt(vcpu, irq);
 }
 
-static void do_interrupt_requests(struct kvm_vcpu *vcpu,
-                                       struct kvm_run *kvm_run)
+static void enable_irq_window(struct kvm_vcpu *vcpu)
 {
         u32 cpu_based_vm_exec_control;
 
-        vmx_update_window_states(vcpu);
+        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
+        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;
+        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
+}
 
-        if (vcpu->arch.interrupt_window_open &&
-            vcpu->arch.irq_summary && !vcpu->arch.interrupt.pending)
-                kvm_do_inject_irq(vcpu);
+static void enable_nmi_window(struct kvm_vcpu *vcpu)
+{
+        u32 cpu_based_vm_exec_control;
 
-        if (vcpu->arch.interrupt_window_open && vcpu->arch.interrupt.pending)
-                vmx_inject_irq(vcpu, vcpu->arch.interrupt.nr);
+        if (!cpu_has_virtual_nmis())
+                return;
 
         cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
+        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_NMI_PENDING;
+        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
+}
+
+static void do_interrupt_requests(struct kvm_vcpu *vcpu,
+                                       struct kvm_run *kvm_run)
+{
+        vmx_update_window_states(vcpu);
+
+        if (vcpu->arch.interrupt_window_open) {
+                if (vcpu->arch.irq_summary && !vcpu->arch.interrupt.pending)
+                        kvm_do_inject_irq(vcpu);
+
+                if (vcpu->arch.interrupt.pending)
+                        vmx_inject_irq(vcpu, vcpu->arch.interrupt.nr);
+        }
         if (!vcpu->arch.interrupt_window_open &&
             (vcpu->arch.irq_summary || kvm_run->request_interrupt_window))
-                /*
-                 * Interrupts blocked.  Wait for unblock.
-                 */
-                cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;
-        else
-                cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
-        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
+                enable_irq_window(vcpu);
 }
 
 static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr)
@@ -3066,35 +3078,6 @@ static void update_tpr_threshold(struct kvm_vcpu *vcpu)
         vmcs_write32(TPR_THRESHOLD, (max_irr > tpr) ? tpr >> 4 : max_irr >> 4);
 }
 
-static void enable_irq_window(struct kvm_vcpu *vcpu)
-{
-        u32 cpu_based_vm_exec_control;
-
-        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
-        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;
-        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
-}
-
-static void enable_nmi_window(struct kvm_vcpu *vcpu)
-{
-        u32 cpu_based_vm_exec_control;
-
-        if (!cpu_has_virtual_nmis())
-                return;
-
-        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
-        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_NMI_PENDING;
-        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
-}
-
-static void enable_intr_window(struct kvm_vcpu *vcpu)
-{
-        if (vcpu->arch.nmi_pending)
-                enable_nmi_window(vcpu);
-        else if (kvm_cpu_has_interrupt(vcpu))
-                enable_irq_window(vcpu);
-}
-
 static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
 {
         u32 exit_intr_info;
@@ -3165,13 +3148,16 @@ static void vmx_intr_assist(struct kvm_vcpu *vcpu)
                                 vcpu->arch.nmi_pending = false;
                                 vcpu->arch.nmi_injected = true;
                         } else {
-                                enable_intr_window(vcpu);
+                                enable_nmi_window(vcpu);
                                 return;
                         }
                 }
                 if (vcpu->arch.nmi_injected) {
                         vmx_inject_nmi(vcpu);
-                        enable_intr_window(vcpu);
+                        if (vcpu->arch.nmi_pending)
+                                enable_nmi_window(vcpu);
+                        else if (kvm_cpu_has_interrupt(vcpu))
+                                enable_irq_window(vcpu);
                         return;
                 }
         }