Commit b26deb0c authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

KVM: x86: Introduce EM_ASM_2 



Replace the FASTOP2 instructions.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarSean Christopherson <seanjc@google.com>
Link: https://lkml.kernel.org/r/20250714103439.903697475@infradead.org
parent 6204aea3

arch/x86/kvm/emulate.c

+47 −38
Original line number Diff line number Diff line
@@ -317,6 +317,15 @@ static int em_##op(struct x86_emulate_ctxt *ctxt) \ 
	ON64(case 8: __EM_ASM_1(op##q, rax); break;) \

	EM_ASM_END



/* 2-operand, using "a" (dst), "d" (src) */

#define EM_ASM_2(op) \

	EM_ASM_START(op) \

	case 1: __EM_ASM_2(op##b, al, dl); break; \

	case 2: __EM_ASM_2(op##w, ax, dx); break; \

	case 4: __EM_ASM_2(op##l, eax, edx); break; \

	ON64(case 8: __EM_ASM_2(op##q, rax, rdx); break;) \

	EM_ASM_END



/*

 * fastop functions have a special calling convention:

 *
@@ -1027,15 +1036,16 @@ static int read_descriptor(struct x86_emulate_ctxt *ctxt, 
	return rc;

}



FASTOP2(add);

FASTOP2(or);

FASTOP2(adc);

FASTOP2(sbb);

FASTOP2(and);

FASTOP2(sub);

FASTOP2(xor);

FASTOP2(cmp);

FASTOP2(test);

EM_ASM_2(add);

EM_ASM_2(or);

EM_ASM_2(adc);

EM_ASM_2(sbb);

EM_ASM_2(and);

EM_ASM_2(sub);

EM_ASM_2(xor);

EM_ASM_2(cmp);

EM_ASM_2(test);

EM_ASM_2(xadd);



FASTOP1SRC2(mul, mul_ex);

FASTOP1SRC2(imul, imul_ex);
@@ -1067,7 +1077,6 @@ FASTOP2W(bts); 
FASTOP2W(btr);

FASTOP2W(btc);



FASTOP2(xadd);



FASTOP2R(cmp, cmp_r);
@@ -2304,7 +2313,7 @@ static int em_cmpxchg(struct x86_emulate_ctxt *ctxt) 
	ctxt->dst.val = reg_read(ctxt, VCPU_REGS_RAX);

	ctxt->src.orig_val = ctxt->src.val;

	ctxt->src.val = ctxt->dst.orig_val;

	fastop(ctxt, em_cmp);

	em_cmp(ctxt);



	if (ctxt->eflags & X86_EFLAGS_ZF) {

		/* Success: write back to memory; no update of EAX */
@@ -3069,7 +3078,7 @@ static int em_das(struct x86_emulate_ctxt *ctxt) 
	ctxt->src.type = OP_IMM;

	ctxt->src.val = 0;

	ctxt->src.bytes = 1;

	fastop(ctxt, em_or);

	em_or(ctxt);

	ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF);

	if (cf)

		ctxt->eflags |= X86_EFLAGS_CF;
@@ -3095,7 +3104,7 @@ static int em_aam(struct x86_emulate_ctxt *ctxt) 
	ctxt->src.type = OP_IMM;

	ctxt->src.val = 0;

	ctxt->src.bytes = 1;

	fastop(ctxt, em_or);

	em_or(ctxt);



	return X86EMUL_CONTINUE;

}
@@ -3113,7 +3122,7 @@ static int em_aad(struct x86_emulate_ctxt *ctxt) 
	ctxt->src.type = OP_IMM;

	ctxt->src.val = 0;

	ctxt->src.bytes = 1;

	fastop(ctxt, em_or);

	em_or(ctxt);



	return X86EMUL_CONTINUE;

}
@@ -3998,9 +4007,9 @@ static int check_perm_out(struct x86_emulate_ctxt *ctxt) 
#define I2bvIP(_f, _e, _i, _p) \

	IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p)



#define F6ALU(_f, _e) F2bv((_f) | DstMem | SrcReg | ModRM, _e),		\

		F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e),	\

		F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e)

#define I6ALU(_f, _e) I2bv((_f) | DstMem | SrcReg | ModRM, _e),		\

		I2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e),	\

		I2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e)



static const struct opcode group7_rm0[] = {

	N,
@@ -4038,14 +4047,14 @@ static const struct opcode group7_rm7[] = { 
};



static const struct opcode group1[] = {

	F(Lock, em_add),

	F(Lock | PageTable, em_or),

	F(Lock, em_adc),

	F(Lock, em_sbb),

	F(Lock | PageTable, em_and),

	F(Lock, em_sub),

	F(Lock, em_xor),

	F(NoWrite, em_cmp),

	I(Lock, em_add),

	I(Lock | PageTable, em_or),

	I(Lock, em_adc),

	I(Lock, em_sbb),

	I(Lock | PageTable, em_and),

	I(Lock, em_sub),

	I(Lock, em_xor),

	I(NoWrite, em_cmp),

};



static const struct opcode group1A[] = {
@@ -4064,8 +4073,8 @@ static const struct opcode group2[] = { 
};



static const struct opcode group3[] = {

	F(DstMem | SrcImm | NoWrite, em_test),

	F(DstMem | SrcImm | NoWrite, em_test),

	I(DstMem | SrcImm | NoWrite, em_test),

	I(DstMem | SrcImm | NoWrite, em_test),

	I(DstMem | SrcNone | Lock, em_not),

	I(DstMem | SrcNone | Lock, em_neg),

	F(DstXacc | Src2Mem, em_mul_ex),
@@ -4258,29 +4267,29 @@ static const struct instr_dual instr_dual_8d = { 


static const struct opcode opcode_table[256] = {

	/* 0x00 - 0x07 */

	F6ALU(Lock, em_add),

	I6ALU(Lock, em_add),

	I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg),

	I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg),

	/* 0x08 - 0x0F */

	F6ALU(Lock | PageTable, em_or),

	I6ALU(Lock | PageTable, em_or),

	I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg),

	N,

	/* 0x10 - 0x17 */

	F6ALU(Lock, em_adc),

	I6ALU(Lock, em_adc),

	I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg),

	I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg),

	/* 0x18 - 0x1F */

	F6ALU(Lock, em_sbb),

	I6ALU(Lock, em_sbb),

	I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg),

	I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg),

	/* 0x20 - 0x27 */

	F6ALU(Lock | PageTable, em_and), N, N,

	I6ALU(Lock | PageTable, em_and), N, N,

	/* 0x28 - 0x2F */

	F6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das),

	I6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das),

	/* 0x30 - 0x37 */

	F6ALU(Lock, em_xor), N, N,

	I6ALU(Lock, em_xor), N, N,

	/* 0x38 - 0x3F */

	F6ALU(NoWrite, em_cmp), N, N,

	I6ALU(NoWrite, em_cmp), N, N,

	/* 0x40 - 0x4F */

	X8(I(DstReg, em_inc)), X8(I(DstReg, em_dec)),

	/* 0x50 - 0x57 */
@@ -4306,7 +4315,7 @@ static const struct opcode opcode_table[256] = { 
	G(DstMem | SrcImm, group1),

	G(ByteOp | DstMem | SrcImm | No64, group1),

	G(DstMem | SrcImmByte, group1),

	F2bv(DstMem | SrcReg | ModRM | NoWrite, em_test),

	I2bv(DstMem | SrcReg | ModRM | NoWrite, em_test),

	I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg),

	/* 0x88 - 0x8F */

	I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov),
@@ -4329,7 +4338,7 @@ static const struct opcode opcode_table[256] = { 
	I2bv(SrcSI | DstDI | Mov | String | TwoMemOp, em_mov),

	F2bv(SrcSI | DstDI | String | NoWrite | TwoMemOp, em_cmp_r),

	/* 0xA8 - 0xAF */

	F2bv(DstAcc | SrcImm | NoWrite, em_test),

	I2bv(DstAcc | SrcImm | NoWrite, em_test),

	I2bv(SrcAcc | DstDI | Mov | String, em_mov),

	I2bv(SrcSI | DstAcc | Mov | String, em_mov),

	F2bv(SrcAcc | DstDI | String | NoWrite, em_cmp_r),
@@ -4467,7 +4476,7 @@ static const struct opcode twobyte_table[256] = { 
	I(DstReg | SrcMem | ModRM, em_bsr_c),

	D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),

	/* 0xC0 - 0xC7 */

	F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd),

	I2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd),

	N, ID(0, &instr_dual_0f_c3),

	N, N, N, GD(0, &group9),

	/* 0xC8 - 0xCF */