diff options
| -rw-r--r-- | arch/x86/kvm/emulate.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 5719d8cfdbd9..e86d610dc6b7 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -429,8 +429,23 @@ 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: + * + * SETcc %al [3 bytes] + * RET [1 byte] + * INT3 [1 byte; CONFIG_SLS] + * + * Which gives possible sizes 4 or 5. When rounded up to the + * next power-of-two alignment they become 4 or 8. + */ +#define SETCC_LENGTH (4 + IS_ENABLED(CONFIG_SLS)) +#define SETCC_ALIGN (4 << IS_ENABLED(CONFIG_SLS)) +static_assert(SETCC_LENGTH <= SETCC_ALIGN); + #define FOP_SETCC(op) \ - ".align 4 \n\t" \ + ".align " __stringify(SETCC_ALIGN) " \n\t" \ ".type " #op ", @function \n\t" \ #op ": \n\t" \ #op " %al \n\t" \ @@ -1047,7 +1062,7 @@ 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 + 4 * (condition & 0xf); + void (*fop)(void) = (void *)em_setcc + SETCC_ALIGN * (condition & 0xf); flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF; asm("push %[flags]; popf; " CALL_NOSPEC |