linux-kernel - [PATCH 04/10] KVM: emulate: move op_prefix to struct x86_emulate

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Message-ID: <20251114003633.60689-5-pbonzini@redhat.com>
Date: Thu, 13 Nov 2025 19:36:27 -0500
From: Paolo Bonzini <pbonzini@...hat.com>
To: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Cc: kbusch@...nel.org,
	chang.seok.bae@...el.com
Subject: [PATCH 04/10] KVM: emulate: move op_prefix to struct x86_emulate_ctxt

VEX decode will need to set it based on the "pp" bits, so make it
a field in the struct rather than a local variable.

No functional change intended.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/emulate.c     | 8 ++++----
 arch/x86/kvm/kvm_emulate.h | 1 +
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 28f81346878e..7ef791407dbc 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4761,7 +4761,6 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int
 	int rc = X86EMUL_CONTINUE;
 	int mode = ctxt->mode;
 	int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
-	bool op_prefix = false;
 	bool has_seg_override = false;
 	struct opcode opcode;
 	u16 dummy;
@@ -4813,7 +4812,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int
 	for (;;) {
 		switch (ctxt->b = insn_fetch(u8, ctxt)) {
 		case 0x66:	/* operand-size override */
-			op_prefix = true;
+			ctxt->op_prefix = true;
 			/* switch between 2/4 bytes */
 			ctxt->op_bytes = def_op_bytes ^ 6;
 			break;
@@ -4920,9 +4919,9 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int
 			opcode = opcode.u.group[goffset];
 			break;
 		case Prefix:
-			if (ctxt->rep_prefix && op_prefix)
+			if (ctxt->rep_prefix && ctxt->op_prefix)
 				return EMULATION_FAILED;
-			simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix;
+			simd_prefix = ctxt->op_prefix ? 0x66 : ctxt->rep_prefix;
 			switch (simd_prefix) {
 			case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
 			case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
@@ -5140,6 +5139,7 @@ void init_decode_cache(struct x86_emulate_ctxt *ctxt)
 	ctxt->rip_relative = false;
 	ctxt->rex_prefix = 0;
 	ctxt->lock_prefix = 0;
+	ctxt->op_prefix = false;
 	ctxt->rep_prefix = 0;
 	ctxt->regs_valid = 0;
 	ctxt->regs_dirty = 0;
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 7b5ddb787a25..83af019620e3 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -348,6 +348,7 @@ struct x86_emulate_ctxt {
 	u8 opcode_len;
 	u8 b;
 	u8 intercept;
+	bool op_prefix;
 	u8 op_bytes;
 	u8 ad_bytes;
 	union {
-- 
2.43.5