KVM: x86: Remove return code from enable_irq/nmi_window

It's no longer possible to enter enable_irq_window in guest mode when
L1 intercepts external interrupts and we are entering L2. This is now
caught in vcpu_enter_guest. So we can remove the check from the VMX
version of enable_irq_window, thus the need to return an error code from
both enable_irq_window and enable_nmi_window.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 7 insertions, 18 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2c9d21e2d033..fcc1947db296 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4514,39 +4514,28 @@ static bool nested_exit_on_nmi(struct kvm_vcpu *vcpu)
                 PIN_BASED_NMI_EXITING;
 }
 
-static int enable_irq_window(struct kvm_vcpu *vcpu)
+static void enable_irq_window(struct kvm_vcpu *vcpu)
 {
         u32 cpu_based_vm_exec_control;
 
-        if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu))
-                /*
-                 * We get here if vmx_interrupt_allowed() said we can't
-                 * inject to L1 now because L2 must run. The caller will have
-                 * to make L2 exit right after entry, so we can inject to L1
-                 * more promptly.
-                 */
-                return -EBUSY;
-
         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);
-        return 0;
 }
 
-static int enable_nmi_window(struct kvm_vcpu *vcpu)
+static void enable_nmi_window(struct kvm_vcpu *vcpu)
 {
         u32 cpu_based_vm_exec_control;
 
-        if (!cpu_has_virtual_nmis())
-                return enable_irq_window(vcpu);
-
-        if (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_STI)
-                return enable_irq_window(vcpu);
+        if (!cpu_has_virtual_nmis() ||
+            vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_STI) {
+                enable_irq_window(vcpu);
+                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);
-        return 0;
 }
 
 static void vmx_inject_irq(struct kvm_vcpu *vcpu)