If CR4.DE=1 access to registers DR4/DR5 cause #UD.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 18 ++++++++++++------
1 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 836e97b..5afddcf 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2531,9 +2531,12 @@ twobyte_insn:
c->dst.type = OP_NONE; /* no writeback */
break;
case 0x21: /* mov from dr to reg */
- if (emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]))
- goto cannot_emulate;
- rc = X86EMUL_CONTINUE;
+ if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
+ (c->modrm_reg == 4 || c->modrm_reg == 5)) {
+ kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
+ goto done;
+ }
+ emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]);
c->dst.type = OP_NONE; /* no writeback */
break;
case 0x22: /* mov reg, cr */
@@ -2541,9 +2544,12 @@ twobyte_insn:
c->dst.type = OP_NONE;
break;
case 0x23: /* mov from reg to dr */
- if (emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm]))
- goto cannot_emulate;
- rc = X86EMUL_CONTINUE;
+ if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
+ (c->modrm_reg == 4 || c->modrm_reg == 5)) {
+ kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
+ goto done;
+ }
+ emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm]);
c->dst.type = OP_NONE; /* no writeback */
break;
case 0x30:
--
1.6.5
--
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