Commit 1e470be5 authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
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KVM: x86 emulator: fix mov dr to inject #UD when needed. 



If CR4.DE=1 access to registers DR4/DR5 cause #UD.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 6aebfa6e

arch/x86/kvm/emulate.c

+12 −6
Original line number Diff line number Diff line
@@ -2531,9 +2531,12 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		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 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		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: