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Commit 35d3d4a1 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: x86 emulator: simplify exception generation 



Immediately after we generate an exception, we want a X86EMUL_PROPAGATE_FAULT
constant, so return it from the generation functions.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent db297e3d

arch/x86/kvm/emulate.c

+50 −90
Original line number Diff line number Diff line
@@ -466,33 +466,33 @@ static ulong linear(struct x86_emulate_ctxt *ctxt, 
	return la;

}



static void emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,

static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,

			     u32 error, bool valid)

{

	ctxt->exception.vector = vec;

	ctxt->exception.error_code = error;

	ctxt->exception.error_code_valid = valid;

	return X86EMUL_PROPAGATE_FAULT;

}



static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err)

static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err)

{

	emulate_exception(ctxt, GP_VECTOR, err, true);

	return emulate_exception(ctxt, GP_VECTOR, err, true);

}



static void emulate_ud(struct x86_emulate_ctxt *ctxt)

static int emulate_ud(struct x86_emulate_ctxt *ctxt)

{

	emulate_exception(ctxt, UD_VECTOR, 0, false);

	return emulate_exception(ctxt, UD_VECTOR, 0, false);

}



static void emulate_ts(struct x86_emulate_ctxt *ctxt, int err)

static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err)

{

	emulate_exception(ctxt, TS_VECTOR, err, true);

	return emulate_exception(ctxt, TS_VECTOR, err, true);

}



static int emulate_de(struct x86_emulate_ctxt *ctxt)

{

	emulate_exception(ctxt, DE_VECTOR, 0, false);

	return X86EMUL_PROPAGATE_FAULT;

	return emulate_exception(ctxt, DE_VECTOR, 0, false);

}



static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt,
@@ -898,10 +898,8 @@ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, 


	get_descriptor_table_ptr(ctxt, ops, selector, &dt);



	if (dt.size < index * 8 + 7) {

		emulate_gp(ctxt, selector & 0xfffc);

		return X86EMUL_PROPAGATE_FAULT;

	}

	if (dt.size < index * 8 + 7)

		return emulate_gp(ctxt, selector & 0xfffc);

	addr = dt.address + index * 8;

	ret = ops->read_std(addr, desc, sizeof *desc, ctxt->vcpu,

			    &ctxt->exception);
@@ -921,10 +919,8 @@ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, 


	get_descriptor_table_ptr(ctxt, ops, selector, &dt);



	if (dt.size < index * 8 + 7) {

		emulate_gp(ctxt, selector & 0xfffc);

		return X86EMUL_PROPAGATE_FAULT;

	}

	if (dt.size < index * 8 + 7)

		return emulate_gp(ctxt, selector & 0xfffc);



	addr = dt.address + index * 8;

	ret = ops->write_std(addr, desc, sizeof *desc, ctxt->vcpu,
@@ -1165,10 +1161,8 @@ static int emulate_popf(struct x86_emulate_ctxt *ctxt, 
			change_mask |= EFLG_IF;

		break;

	case X86EMUL_MODE_VM86:

		if (iopl < 3) {

			emulate_gp(ctxt, 0);

			return X86EMUL_PROPAGATE_FAULT;

		}

		if (iopl < 3)

			return emulate_gp(ctxt, 0);

		change_mask |= EFLG_IF;

		break;

	default: /* real mode */
@@ -1347,10 +1341,8 @@ static int emulate_iret_real(struct x86_emulate_ctxt *ctxt, 
	if (rc != X86EMUL_CONTINUE)

		return rc;



	if (temp_eip & ~0xffff) {

		emulate_gp(ctxt, 0);

		return X86EMUL_PROPAGATE_FAULT;

	}

	if (temp_eip & ~0xffff)

		return emulate_gp(ctxt, 0);



	rc = emulate_pop(ctxt, ops, &cs, c->op_bytes);
@@ -1601,10 +1593,8 @@ emulate_syscall(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 


	/* syscall is not available in real mode */

	if (ctxt->mode == X86EMUL_MODE_REAL ||

	    ctxt->mode == X86EMUL_MODE_VM86) {

		emulate_ud(ctxt);

		return X86EMUL_PROPAGATE_FAULT;

	}

	    ctxt->mode == X86EMUL_MODE_VM86)

		return emulate_ud(ctxt);



	setup_syscalls_segments(ctxt, ops, &cs, &ss);
@@ -1655,34 +1645,26 @@ emulate_sysenter(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
	u16 cs_sel, ss_sel;



	/* inject #GP if in real mode */

	if (ctxt->mode == X86EMUL_MODE_REAL) {

		emulate_gp(ctxt, 0);

		return X86EMUL_PROPAGATE_FAULT;

	}

	if (ctxt->mode == X86EMUL_MODE_REAL)

		return emulate_gp(ctxt, 0);



	/* XXX sysenter/sysexit have not been tested in 64bit mode.

	* Therefore, we inject an #UD.

	*/

	if (ctxt->mode == X86EMUL_MODE_PROT64) {

		emulate_ud(ctxt);

		return X86EMUL_PROPAGATE_FAULT;

	}

	if (ctxt->mode == X86EMUL_MODE_PROT64)

		return emulate_ud(ctxt);



	setup_syscalls_segments(ctxt, ops, &cs, &ss);



	ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data);

	switch (ctxt->mode) {

	case X86EMUL_MODE_PROT32:

		if ((msr_data & 0xfffc) == 0x0) {

			emulate_gp(ctxt, 0);

			return X86EMUL_PROPAGATE_FAULT;

		}

		if ((msr_data & 0xfffc) == 0x0)

			return emulate_gp(ctxt, 0);

		break;

	case X86EMUL_MODE_PROT64:

		if (msr_data == 0x0) {

			emulate_gp(ctxt, 0);

			return X86EMUL_PROPAGATE_FAULT;

		}

		if (msr_data == 0x0)

			return emulate_gp(ctxt, 0);

		break;

	}
@@ -1722,10 +1704,8 @@ emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 


	/* inject #GP if in real mode or Virtual 8086 mode */

	if (ctxt->mode == X86EMUL_MODE_REAL ||

	    ctxt->mode == X86EMUL_MODE_VM86) {

		emulate_gp(ctxt, 0);

		return X86EMUL_PROPAGATE_FAULT;

	}

	    ctxt->mode == X86EMUL_MODE_VM86)

		return emulate_gp(ctxt, 0);



	setup_syscalls_segments(ctxt, ops, &cs, &ss);
@@ -1740,18 +1720,14 @@ emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
	switch (usermode) {

	case X86EMUL_MODE_PROT32:

		cs_sel = (u16)(msr_data + 16);

		if ((msr_data & 0xfffc) == 0x0) {

			emulate_gp(ctxt, 0);

			return X86EMUL_PROPAGATE_FAULT;

		}

		if ((msr_data & 0xfffc) == 0x0)

			return emulate_gp(ctxt, 0);

		ss_sel = (u16)(msr_data + 24);

		break;

	case X86EMUL_MODE_PROT64:

		cs_sel = (u16)(msr_data + 32);

		if (msr_data == 0x0) {

			emulate_gp(ctxt, 0);

			return X86EMUL_PROPAGATE_FAULT;

		}

		if (msr_data == 0x0)

			return emulate_gp(ctxt, 0);

		ss_sel = cs_sel + 8;

		cs.d = 0;

		cs.l = 1;
@@ -1982,10 +1958,8 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, 
	struct decode_cache *c = &ctxt->decode;

	int ret;



	if (ops->set_cr(3, tss->cr3, ctxt->vcpu)) {

		emulate_gp(ctxt, 0);

		return X86EMUL_PROPAGATE_FAULT;

	}

	if (ops->set_cr(3, tss->cr3, ctxt->vcpu))

		return emulate_gp(ctxt, 0);

	c->eip = tss->eip;

	ctxt->eflags = tss->eflags | 2;

	c->regs[VCPU_REGS_RAX] = tss->eax;
@@ -2107,10 +2081,8 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, 


	if (reason != TASK_SWITCH_IRET) {

		if ((tss_selector & 3) > next_tss_desc.dpl ||

		    ops->cpl(ctxt->vcpu) > next_tss_desc.dpl) {

			emulate_gp(ctxt, 0);

			return X86EMUL_PROPAGATE_FAULT;

		}

		    ops->cpl(ctxt->vcpu) > next_tss_desc.dpl)

			return emulate_gp(ctxt, 0);

	}



	desc_limit = desc_limit_scaled(&next_tss_desc);
@@ -2331,10 +2303,8 @@ static int em_rdtsc(struct x86_emulate_ctxt *ctxt) 
	struct decode_cache *c = &ctxt->decode;

	u64 tsc = 0;



	if (cpl > 0 && (ctxt->ops->get_cr(4, ctxt->vcpu) & X86_CR4_TSD)) {

		emulate_gp(ctxt, 0);

		return X86EMUL_PROPAGATE_FAULT;

	}

	if (cpl > 0 && (ctxt->ops->get_cr(4, ctxt->vcpu) & X86_CR4_TSD))

		return emulate_gp(ctxt, 0);

	ctxt->ops->get_msr(ctxt->vcpu, MSR_IA32_TSC, &tsc);

	c->regs[VCPU_REGS_RAX] = (u32)tsc;

	c->regs[VCPU_REGS_RDX] = tsc >> 32;
@@ -2979,28 +2949,24 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	ctxt->decode.mem_read.pos = 0;



	if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {

		emulate_ud(ctxt);

		rc = X86EMUL_PROPAGATE_FAULT;

		rc = emulate_ud(ctxt);

		goto done;

	}



	/* LOCK prefix is allowed only with some instructions */

	if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) {

		emulate_ud(ctxt);

		rc = X86EMUL_PROPAGATE_FAULT;

		rc = emulate_ud(ctxt);

		goto done;

	}



	if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) {

		emulate_ud(ctxt);

		rc = X86EMUL_PROPAGATE_FAULT;

		rc = emulate_ud(ctxt);

		goto done;

	}



	/* Privileged instruction can be executed only in CPL=0 */

	if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) {

		emulate_gp(ctxt, 0);

		rc = X86EMUL_PROPAGATE_FAULT;

		rc = emulate_gp(ctxt, 0);

		goto done;

	}
@@ -3178,8 +3144,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		break;

	case 0x8c:  /* mov r/m, sreg */

		if (c->modrm_reg > VCPU_SREG_GS) {

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			rc = emulate_ud(ctxt);

			goto done;

		}

		c->dst.val = ops->get_segment_selector(c->modrm_reg, ctxt->vcpu);
@@ -3194,8 +3159,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 


		if (c->modrm_reg == VCPU_SREG_CS ||

		    c->modrm_reg > VCPU_SREG_GS) {

			emulate_ud(ctxt);

			rc = X86EMUL_PROPAGATE_FAULT;

			rc = emulate_ud(ctxt);

			goto done;

		}
@@ -3327,8 +3291,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	do_io_in:

		c->dst.bytes = min(c->dst.bytes, 4u);

		if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			rc = emulate_gp(ctxt, 0);

			goto done;

		}

		if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val,
@@ -3342,8 +3305,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		c->src.bytes = min(c->src.bytes, 4u);

		if (!emulator_io_permited(ctxt, ops, c->dst.val,

					  c->src.bytes)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			rc = emulate_gp(ctxt, 0);

			goto done;

		}

		ops->pio_out_emulated(c->src.bytes, c->dst.val,
@@ -3368,16 +3330,14 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
		break;

	case 0xfa: /* cli */

		if (emulator_bad_iopl(ctxt, ops)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			rc = emulate_gp(ctxt, 0);

			goto done;

		} else

			ctxt->eflags &= ~X86_EFLAGS_IF;

		break;

	case 0xfb: /* sti */

		if (emulator_bad_iopl(ctxt, ops)) {

			emulate_gp(ctxt, 0);

			rc = X86EMUL_PROPAGATE_FAULT;

			rc = emulate_gp(ctxt, 0);

			goto done;

		} else {

			ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;