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Commit ab8557b2 authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
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KVM: x86 emulator: 0f (20|21|22|23) ignore mod bits. 



Resent spec says that for 0f (20|21|22|23) the 2 bits in the mod field
are ignored. Interestingly enough older spec says that 11 is only valid
encoding.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 6e1e5ffe

arch/x86/kvm/emulate.c

+0 −8
Original line number Original line Diff line number Diff line
@@ -2520,28 +2520,20 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		c->dst.type = OP_NONE;

		c->dst.type = OP_NONE;

		break;

		break;

	case 0x20: /* mov cr, reg */

	case 0x20: /* mov cr, reg */

		if (c->modrm_mod != 3)

			goto cannot_emulate;

		c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu);

		c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu);

		c->dst.type = OP_NONE;	/* no writeback */

		c->dst.type = OP_NONE;	/* no writeback */

		break;

		break;

	case 0x21: /* mov from dr to reg */

	case 0x21: /* mov from dr to reg */

		if (c->modrm_mod != 3)

			goto cannot_emulate;

		if (emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]))

		if (emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]))

			goto cannot_emulate;

			goto cannot_emulate;

		rc = X86EMUL_CONTINUE;

		rc = X86EMUL_CONTINUE;

		c->dst.type = OP_NONE;	/* no writeback */

		c->dst.type = OP_NONE;	/* no writeback */

		break;

		break;

	case 0x22: /* mov reg, cr */

	case 0x22: /* mov reg, cr */

		if (c->modrm_mod != 3)

			goto cannot_emulate;

		ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu);

		ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu);

		c->dst.type = OP_NONE;

		c->dst.type = OP_NONE;

		break;

		break;

	case 0x23: /* mov from reg to dr */

	case 0x23: /* mov from reg to dr */

		if (c->modrm_mod != 3)

			goto cannot_emulate;

		if (emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm]))

		if (emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm]))

			goto cannot_emulate;

			goto cannot_emulate;

		rc = X86EMUL_CONTINUE;

		rc = X86EMUL_CONTINUE;