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, 2 insertions, 2 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 35f7acd4a91f..c9f604b0819c 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2128,7 +2128,7 @@ special_insn:
                 }
 
                 if (c->modrm_reg == VCPU_SREG_SS)
-                        toggle_interruptibility(ctxt, X86_SHADOW_INT_MOV_SS);
+                        toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_MOV_SS);
 
                 rc = kvm_load_segment_descriptor(ctxt->vcpu, sel, c->modrm_reg);
 
@@ -2366,7 +2366,7 @@ special_insn:
                 if (emulator_bad_iopl(ctxt))
                         kvm_inject_gp(ctxt->vcpu, 0);
                 else {
-                        toggle_interruptibility(ctxt, X86_SHADOW_INT_STI);
+                        toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_STI);
                         ctxt->eflags |= X86_EFLAGS_IF;
                         c->dst.type = OP_NONE;  /* Disable writeback. */
                 }