[PATCH 2/3] x86/kvm: Simplify FOP_SETCC()

From: Josh Poimboeuf
Date: Thu Aug 18 2022 - 12:14:22 EST


SETCC_ALIGN and FOP_ALIGN are both 16. Remove the special casing for
FOP_SETCC() and just make it a normal fastop.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 23 ++++-------------------
1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b4eeb7c75dfa..205d566ebd72 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -446,27 +446,12 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop);
FOP_END

/* Special case for SETcc - 1 instruction per cc */
-
-/*
- * Depending on .config the SETcc functions look like:
- *
- * ENDBR [4 bytes; CONFIG_X86_KERNEL_IBT]
- * SETcc %al [3 bytes]
- * RET | JMP __x86_return_thunk [1,5 bytes; CONFIG_RETHUNK]
- * INT3 [1 byte; CONFIG_SLS]
- */
-#define SETCC_ALIGN 16
-
#define FOP_SETCC(op) \
- ".align " __stringify(SETCC_ALIGN) " \n\t" \
- ".type " #op ", @function \n\t" \
- #op ": \n\t" \
- ASM_ENDBR \
+ FOP_FUNC(op) \
#op " %al \n\t" \
- __FOP_RET(#op) \
- ".skip " __stringify(SETCC_ALIGN) " - (.-" #op "), 0xcc \n\t"
+ FOP_RET(op)

-__FOP_START(setcc, SETCC_ALIGN)
+FOP_START(setcc)
FOP_SETCC(seto)
FOP_SETCC(setno)
FOP_SETCC(setc)
@@ -1079,7 +1064,7 @@ static int em_bsr_c(struct x86_emulate_ctxt *ctxt)
static __always_inline u8 test_cc(unsigned int condition, unsigned long flags)
{
u8 rc;
- void (*fop)(void) = (void *)em_setcc + SETCC_ALIGN * (condition & 0xf);
+ void (*fop)(void) = (void *)em_setcc + FASTOP_SIZE * (condition & 0xf);

flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
asm("push %[flags]; popf; " CALL_NOSPEC
--
2.37.2