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Commit f6511935 authored by Joerg Roedel's avatar Joerg Roedel Committed by Avi Kivity
Browse files

KVM: SVM: Add checks for IO instructions 



This patch adds code to check for IOIO intercepts on
instructions decoded by the KVM instruction emulator.

[avi: fix build error due to missing #define D2bvIP]

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent bf608f88

arch/x86/include/asm/kvm_emulate.h

+4 −0
Original line number Diff line number Diff line
@@ -346,6 +346,10 @@ enum x86_intercept { 
	x86_intercept_mwait,

	x86_intercept_rdmsr,

	x86_intercept_wrmsr,

	x86_intercept_in,

	x86_intercept_ins,

	x86_intercept_out,

	x86_intercept_outs,



	nr_x86_intercepts

};

arch/x86/kvm/emulate.c

+30 −15
Original line number Diff line number Diff line
@@ -2623,6 +2623,28 @@ static int check_rdpmc(struct x86_emulate_ctxt *ctxt) 
	return X86EMUL_CONTINUE;

}



static int check_perm_in(struct x86_emulate_ctxt *ctxt)

{

	struct decode_cache *c = &ctxt->decode;



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

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

		return emulate_gp(ctxt, 0);



	return X86EMUL_CONTINUE;

}



static int check_perm_out(struct x86_emulate_ctxt *ctxt)

{

	struct decode_cache *c = &ctxt->decode;



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

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

		return emulate_gp(ctxt, 0);



	return X86EMUL_CONTINUE;

}



#define D(_y) { .flags = (_y) }

#define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i }

#define DIP(_y, _i, _p) { .flags = (_y), .intercept = x86_intercept_##_i, \
@@ -2640,6 +2662,7 @@ static int check_rdpmc(struct x86_emulate_ctxt *ctxt) 
#define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) }



#define D2bv(_f)      D((_f) | ByteOp), D(_f)

#define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p)

#define I2bv(_f, _e)  I((_f) | ByteOp, _e), I(_f, _e)



#define D6ALU(_f) D2bv((_f) | DstMem | SrcReg | ModRM),			\
@@ -2773,8 +2796,8 @@ static struct opcode opcode_table[256] = { 
	I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),

	I(SrcImmByte | Mov | Stack, em_push),

	I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),

	D2bv(DstDI | Mov | String), /* insb, insw/insd */

	D2bv(SrcSI | ImplicitOps | String), /* outsb, outsw/outsd */

	D2bvIP(DstDI | Mov | String, ins, check_perm_in), /* insb, insw/insd */

	D2bvIP(SrcSI | ImplicitOps | String, outs, check_perm_out), /* outsb, outsw/outsd */

	/* 0x70 - 0x7F */

	X16(D(SrcImmByte)),

	/* 0x80 - 0x87 */
@@ -2825,11 +2848,13 @@ static struct opcode opcode_table[256] = { 
	N, N, N, N, N, N, N, N,

	/* 0xE0 - 0xE7 */

	X4(D(SrcImmByte)),

	D2bv(SrcImmUByte | DstAcc), D2bv(SrcAcc | DstImmUByte),

	D2bvIP(SrcImmUByte | DstAcc, in,  check_perm_in),

	D2bvIP(SrcAcc | DstImmUByte, out, check_perm_out),

	/* 0xE8 - 0xEF */

	D(SrcImm | Stack), D(SrcImm | ImplicitOps),

	D(SrcImmFAddr | No64), D(SrcImmByte | ImplicitOps),

	D2bv(SrcNone | DstAcc),	D2bv(SrcAcc | ImplicitOps),

	D2bvIP(SrcNone | DstAcc,     in,  check_perm_in),

	D2bvIP(SrcAcc | ImplicitOps, out, check_perm_out),

	/* 0xF0 - 0xF7 */

	N, DI(ImplicitOps, icebp), N, N,

	DI(ImplicitOps | Priv, hlt), D(ImplicitOps),
@@ -2923,6 +2948,7 @@ static struct opcode twobyte_table[256] = { 
#undef EXT



#undef D2bv

#undef D2bvIP

#undef I2bv

#undef D6ALU
@@ -3731,11 +3757,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	case 0xed: /* in (e/r)ax,dx */

		c->src.val = c->regs[VCPU_REGS_RDX];

	do_io_in:

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

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

			rc = emulate_gp(ctxt, 0);

			goto done;

		}

		if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val,

				     &c->dst.val))

			goto done; /* IO is needed */
@@ -3744,12 +3765,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	case 0xef: /* out dx,(e/r)ax */

		c->dst.val = c->regs[VCPU_REGS_RDX];

	do_io_out:

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

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

					  c->src.bytes)) {

			rc = emulate_gp(ctxt, 0);

			goto done;

		}

		ops->pio_out_emulated(c->src.bytes, c->dst.val,

				      &c->src.val, 1, ctxt->vcpu);

		c->dst.type = OP_NONE;	/* Disable writeback. */

arch/x86/kvm/svm.c

+36 −0
Original line number Diff line number Diff line
@@ -3925,6 +3925,10 @@ static struct __x86_intercept { 
	[x86_intercept_iret]		= PRE_EX(SVM_EXIT_IRET),

	[x86_intercept_icebp]		= PRE_EX(SVM_EXIT_ICEBP),

	[x86_intercept_hlt]		= POST_EX(SVM_EXIT_HLT),

	[x86_intercept_in]		= POST_EX(SVM_EXIT_IOIO),

	[x86_intercept_ins]		= POST_EX(SVM_EXIT_IOIO),

	[x86_intercept_out]		= POST_EX(SVM_EXIT_IOIO),

	[x86_intercept_outs]		= POST_EX(SVM_EXIT_IOIO),

};



#undef PRE_EX
@@ -4001,6 +4005,38 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu, 
		 */

		if (info->rep_prefix != REPE_PREFIX)

			goto out;

	case SVM_EXIT_IOIO: {

		u64 exit_info;

		u32 bytes;



		exit_info = (vcpu->arch.regs[VCPU_REGS_RDX] & 0xffff) << 16;



		if (info->intercept == x86_intercept_in ||

		    info->intercept == x86_intercept_ins) {

			exit_info |= SVM_IOIO_TYPE_MASK;

			bytes = info->src_bytes;

		} else {

			bytes = info->dst_bytes;

		}



		if (info->intercept == x86_intercept_outs ||

		    info->intercept == x86_intercept_ins)

			exit_info |= SVM_IOIO_STR_MASK;



		if (info->rep_prefix)

			exit_info |= SVM_IOIO_REP_MASK;



		bytes = min(bytes, 4u);



		exit_info |= bytes << SVM_IOIO_SIZE_SHIFT;



		exit_info |= (u32)info->ad_bytes << (SVM_IOIO_ASIZE_SHIFT - 1);



		vmcb->control.exit_info_1 = exit_info;

		vmcb->control.exit_info_2 = info->next_rip;



		break;

	}

	default:

		break;

	}