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Commit 58b7075d authored by Nadav Amit's avatar Nadav Amit Committed by Paolo Bonzini
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KVM: x86: Distinguish between stack operation and near branches 



In 64-bit, stack operations default to 64-bits, but can be overriden (to
16-bit) using opsize override prefix. In contrast, near-branches are always
64-bit.  This patch distinguish between the different behaviors.

Signed-off-by: default avatarNadav Amit <namit@cs.technion.ac.il>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f7784046

arch/x86/kvm/emulate.c

+19 −13
Original line number Diff line number Diff line
@@ -166,6 +166,7 @@ 
#define CheckPerm   ((u64)1 << 49)  /* Has valid check_perm field */

#define NoBigReal   ((u64)1 << 50)  /* No big real mode */

#define PrivUD      ((u64)1 << 51)  /* #UD instead of #GP on CPL > 0 */

#define NearBranch  ((u64)1 << 52)  /* Near branches */



#define DstXacc     (DstAccLo | SrcAccHi | SrcWrite)
@@ -3771,9 +3772,9 @@ static const struct opcode group4[] = { 
static const struct opcode group5[] = {

	F(DstMem | SrcNone | Lock,		em_inc),

	F(DstMem | SrcNone | Lock,		em_dec),

	I(SrcMem | Stack,			em_call_near_abs),

	I(SrcMem | NearBranch,			em_call_near_abs),

	I(SrcMemFAddr | ImplicitOps | Stack,	em_call_far),

	I(SrcMem | Stack,			em_jmp_abs),

	I(SrcMem | NearBranch,			em_jmp_abs),

	I(SrcMemFAddr | ImplicitOps,		em_jmp_far),

	I(SrcMem | Stack,			em_push), D(Undefined),

};
@@ -3955,7 +3956,7 @@ static const struct opcode opcode_table[256] = { 
	I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */

	I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */

	/* 0x70 - 0x7F */

	X16(D(SrcImmByte)),

	X16(D(SrcImmByte | NearBranch)),

	/* 0x80 - 0x87 */

	G(ByteOp | DstMem | SrcImm, group1),

	G(DstMem | SrcImm, group1),
@@ -3994,8 +3995,8 @@ static const struct opcode opcode_table[256] = { 
	X8(I(DstReg | SrcImm64 | Mov, em_mov)),

	/* 0xC0 - 0xC7 */

	G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2),

	I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm),

	I(ImplicitOps | Stack, em_ret),

	I(ImplicitOps | NearBranch | SrcImmU16, em_ret_near_imm),

	I(ImplicitOps | NearBranch, em_ret),

	I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg),

	I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),

	G(ByteOp, group11), G(0, group11),
@@ -4015,13 +4016,14 @@ static const struct opcode opcode_table[256] = { 
	/* 0xD8 - 0xDF */

	N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,

	/* 0xE0 - 0xE7 */

	X3(I(SrcImmByte, em_loop)),

	I(SrcImmByte, em_jcxz),

	X3(I(SrcImmByte | NearBranch, em_loop)),

	I(SrcImmByte | NearBranch, em_jcxz),

	I2bvIP(SrcImmUByte | DstAcc, em_in,  in,  check_perm_in),

	I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out),

	/* 0xE8 - 0xEF */

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

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

	I(SrcImm | NearBranch, em_call), D(SrcImm | ImplicitOps | NearBranch),

	I(SrcImmFAddr | No64, em_jmp_far),

	D(SrcImmByte | ImplicitOps | NearBranch),

	I2bvIP(SrcDX | DstAcc, em_in,  in,  check_perm_in),

	I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out),

	/* 0xF0 - 0xF7 */
@@ -4081,7 +4083,7 @@ static const struct opcode twobyte_table[256] = { 
	N, N, N, N,

	N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f),

	/* 0x80 - 0x8F */

	X16(D(SrcImm)),

	X16(D(SrcImm | NearBranch)),

	/* 0x90 - 0x9F */

	X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),

	/* 0xA0 - 0xA7 */
@@ -4550,7 +4552,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 
		return EMULATION_FAILED;



	if (unlikely(ctxt->d &

		     (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm))) {

	    (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch))) {

		/*

		 * These are copied unconditionally here, and checked unconditionally

		 * in x86_emulate_insn.
@@ -4561,8 +4563,12 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 
		if (ctxt->d & NotImpl)

			return EMULATION_FAILED;



		if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack))

		if (mode == X86EMUL_MODE_PROT64) {

			if (ctxt->op_bytes == 4 && (ctxt->d & Stack))

				ctxt->op_bytes = 8;

			else if (ctxt->d & NearBranch)

				ctxt->op_bytes = 8;

		}



		if (ctxt->d & Op3264) {

			if (mode == X86EMUL_MODE_PROT64)