aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kvm
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/x86.c6
-rw-r--r--arch/x86/kvm/x86_emulate.c20
2 files changed, 25 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7475b029b2a..48f744ff0bc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2379,7 +2379,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
u16 error_code,
int emulation_type)
{
- int r;
+ int r, shadow_mask;
struct decode_cache *c;
kvm_clear_exception_queue(vcpu);
@@ -2433,6 +2433,10 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
}
r = x86_emulate_insn(&vcpu->arch.emulate_ctxt, &emulate_ops);
+ shadow_mask = vcpu->arch.emulate_ctxt.interruptibility;
+
+ if (r == 0)
+ kvm_x86_ops->set_interrupt_shadow(vcpu, shadow_mask);
if (vcpu->arch.pio.string)
return EMULATE_DO_MMIO;
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index d2664fcba7f..c1b6c232e02 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -1361,6 +1361,20 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
return 0;
}
+void toggle_interruptibility(struct x86_emulate_ctxt *ctxt, u32 mask)
+{
+ u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(ctxt->vcpu, mask);
+ /*
+ * an sti; sti; sequence only disable interrupts for the first
+ * instruction. So, if the last instruction, be it emulated or
+ * not, left the system with the INT_STI flag enabled, it
+ * means that the last instruction is an sti. We should not
+ * leave the flag on in this case. The same goes for mov ss
+ */
+ if (!(int_shadow & mask))
+ ctxt->interruptibility = mask;
+}
+
int
x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
{
@@ -1372,6 +1386,8 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
int io_dir_in;
int rc = 0;
+ ctxt->interruptibility = 0;
+
/* Shadow copy of register state. Committed on successful emulation.
* NOTE: we can copy them from vcpu as x86_decode_insn() doesn't
* modify them.
@@ -1618,6 +1634,9 @@ special_insn:
int err;
sel = c->src.val;
+ if (c->modrm_reg == VCPU_SREG_SS)
+ toggle_interruptibility(ctxt, X86_SHADOW_INT_MOV_SS);
+
if (c->modrm_reg <= 5) {
type_bits = (c->modrm_reg == 1) ? 9 : 1;
err = kvm_load_segment_descriptor(ctxt->vcpu, sel,
@@ -1847,6 +1866,7 @@ special_insn:
c->dst.type = OP_NONE; /* Disable writeback. */
break;
case 0xfb: /* sti */
+ toggle_interruptibility(ctxt, X86_SHADOW_INT_STI);
ctxt->eflags |= X86_EFLAGS_IF;
c->dst.type = OP_NONE; /* Disable writeback. */
break;