linux-kernel - [tip: x86/core] KVM: x86: Introduce EM_ASM

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Message-ID: <175568275391.1420.13712155174498779791.tip-bot2@tip-bot2>
Date: Wed, 20 Aug 2025 09:39:13 -0000
From: "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@...radead.org>,
 Sean Christopherson <seanjc@...gle.com>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: x86/core] KVM: x86: Introduce EM_ASM_3WCL

The following commit has been merged into the x86/core branch of tip:

Commit-ID:     2d82acd7d6a7eba2ed2bf84ab7440c1ad7c27958
Gitweb:        https://git.kernel.org/tip/2d82acd7d6a7eba2ed2bf84ab7440c1ad7c27958
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Sat, 26 Apr 2025 12:47:50 +02:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Mon, 18 Aug 2025 14:23:06 +02:00

KVM: x86: Introduce EM_ASM_3WCL

Replace the FASTOP3WCL instructions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Acked-by: Sean Christopherson <seanjc@...gle.com>
Link: https://lkml.kernel.org/r/20250714103440.513865075@infradead.org
---
 arch/x86/kvm/emulate.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index beac2f4..390b8a9 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -302,6 +302,9 @@ static int em_##op(struct x86_emulate_ctxt *ctxt) \
 #define __EM_ASM_2(op, dst, src) \
 		__EM_ASM(#op " %%" #src ", %%" #dst " \n\t")
 
+#define __EM_ASM_3(op, dst, src, src2) \
+		__EM_ASM(#op " %%" #src2 ", %%" #src ", %%" #dst " \n\t")
+
 #define EM_ASM_END \
 	} \
 	ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); \
@@ -371,6 +374,16 @@ static int em_##op(struct x86_emulate_ctxt *ctxt) \
 	ON64(case 8: __EM_ASM_2(op##q, rax, cl); break;) \
 	EM_ASM_END
 
+/* 3-operand, using "a" (dst), "d" (src) and CL (src2) */
+#define EM_ASM_3WCL(op) \
+	EM_ASM_START(op) \
+	case 1: break; \
+	case 2: __EM_ASM_3(op##w, ax, dx, cl); break; \
+	case 4: __EM_ASM_3(op##l, eax, edx, cl); break; \
+	ON64(case 8: __EM_ASM_3(op##q, rax, rdx, cl); break;) \
+	EM_ASM_END
+
+
 /*
  * fastop functions have a special calling convention:
  *
@@ -1097,8 +1110,8 @@ EM_ASM_1SRC2(imul, imul_ex);
 EM_ASM_1SRC2EX(div, div_ex);
 EM_ASM_1SRC2EX(idiv, idiv_ex);
 
-FASTOP3WCL(shld);
-FASTOP3WCL(shrd);
+EM_ASM_3WCL(shld);
+EM_ASM_3WCL(shrd);
 
 EM_ASM_2W(imul);
 
@@ -4496,14 +4509,14 @@ static const struct opcode twobyte_table[256] = {
 	I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg),
 	II(ImplicitOps, em_cpuid, cpuid),
 	I(DstMem | SrcReg | ModRM | BitOp | NoWrite, em_bt),
-	F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld),
-	F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N,
+	I(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld),
+	I(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N,
 	/* 0xA8 - 0xAF */
 	I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg),
 	II(EmulateOnUD | ImplicitOps, em_rsm, rsm),
 	I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
-	F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
-	F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
+	I(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
+	I(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
 	GD(0, &group15), I(DstReg | SrcMem | ModRM, em_imul),
 	/* 0xB0 - 0xB7 */
 	I2bv(DstMem | SrcReg | ModRM | Lock | PageTable | SrcWrite, em_cmpxchg),