KVM: x86: Save&restore interrupt shadow mask

The interrupt shadow created by STI or MOV-SS-like operations is part of
the VCPU state and must be preserved across migration. Transfer it in
the spare padding field of kvm_vcpu_events.interrupt.

As a side effect we now have to make vmx_set_interrupt_shadow robust
against both shadow types being set. Give MOV SS a higher priority and
skip STI in that case to avoid that VMX throws a fault on next entry.

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

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 68f895b00450..61f03980adae 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -846,9 +846,9 @@ static u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
         int ret = 0;
 
         if (interruptibility & GUEST_INTR_STATE_STI)
-                ret |= X86_SHADOW_INT_STI;
+                ret |= KVM_X86_SHADOW_INT_STI;
         if (interruptibility & GUEST_INTR_STATE_MOV_SS)
-                ret |= X86_SHADOW_INT_MOV_SS;
+                ret |= KVM_X86_SHADOW_INT_MOV_SS;
 
         return ret & mask;
 }
@@ -860,9 +860,9 @@ static void vmx_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
 
         interruptibility &= ~(GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS);
 
-        if (mask & X86_SHADOW_INT_MOV_SS)
+        if (mask & KVM_X86_SHADOW_INT_MOV_SS)
                 interruptibility |= GUEST_INTR_STATE_MOV_SS;
-        if (mask & X86_SHADOW_INT_STI)
+        else if (mask & KVM_X86_SHADOW_INT_STI)
                 interruptibility |= GUEST_INTR_STATE_STI;
 
         if ((interruptibility != interruptibility_old))