KVM: x86 emulator: Add Virtual-8086 mode of emulation

For some instructions CPU behaves differently for real-mode and
virtual 8086. Let emulator know which mode cpu is in, so it will
not poke into vcpu state directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b2f91b9af00d..a28379507d30 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3348,8 +3348,9 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
                 vcpu->arch.emulate_ctxt.vcpu = vcpu;
                 vcpu->arch.emulate_ctxt.eflags = kvm_get_rflags(vcpu);
                 vcpu->arch.emulate_ctxt.mode =
+                        (!is_protmode(vcpu)) ? X86EMUL_MODE_REAL :
                         (vcpu->arch.emulate_ctxt.eflags & X86_EFLAGS_VM)
-                        ? X86EMUL_MODE_REAL : cs_l
+                        ? X86EMUL_MODE_VM86 : cs_l
                         ? X86EMUL_MODE_PROT64 : cs_db
                         ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;