[PATCH v2 04/13] x86/kvm/emulate: Introduce COP2R

Peter Zijlstra
2025-04-30T11:26:46Z

Replace the FASTOP2R instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kvm/emulate.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -326,6 +326,15 @@ static int em_##op(struct x86_emulate_ct
ON64(case 8: COP_ASM2(op##q, rax, rdx); break;) \
COP_END

+/* 2-operand, reversed */
+#define COP2R(op, name) \
+ COP_START(name) \
+ case 1: COP_ASM2(op##b, dl, al); break; \
+ case 2: COP_ASM2(op##w, dx, ax); break; \
+ case 4: COP_ASM2(op##l, edx, eax); break; \
+ ON64(case 8: COP_ASM2(op##q, rdx, rax); break;) \
+ COP_END
+
/*
* fastop functions have a special calling convention:
*
@@ -1077,8 +1086,7 @@ FASTOP2W(bts);
FASTOP2W(btr);
FASTOP2W(btc);

-
-FASTOP2R(cmp, cmp_r);
+COP2R(cmp, cmp_r);

static int em_bsf_c(struct x86_emulate_ctxt *ctxt)
{
@@ -4336,12 +4344,12 @@ static const struct opcode opcode_table[
I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov),
I2bv(SrcSI | DstDI | Mov | String | TwoMemOp, em_mov),
- F2bv(SrcSI | DstDI | String | NoWrite | TwoMemOp, em_cmp_r),
+ I2bv(SrcSI | DstDI | String | NoWrite | TwoMemOp, em_cmp_r),
/* 0xA8 - 0xAF */
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),
+ I2bv(SrcAcc | DstDI | String | NoWrite, em_cmp_r),
/* 0xB0 - 0xB7 */
X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
/* 0xB8 - 0xBF */