This is a bit of a special case since we don't have the usual
byte/word/long/quad switch; instead we switch on the condition code embedded
in the instruction.
Signed-off-by: Avi Kivity <avi.kiv...@gmail.com>
---
arch/x86/kvm/emulate.c | 60 ++++++++++++++++++++++++--------------------------
1 file changed, 29 insertions(+), 31 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a94b1d7..e13138d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -499,6 +499,28 @@ static void invalidate_registers(struct x86_emulate_ctxt
*ctxt)
ON64(FOP3E(op##q, rax, rbx, cl)) \
FOP_END
+/* Special case for SETcc - 1 instruction per cc */
+#define FOP_SETCC(op) ".align 4; " #op " %al; ret \n\t"
+
+FOP_START(setcc)
+FOP_SETCC(seto)
+FOP_SETCC(setno)
+FOP_SETCC(setc)
+FOP_SETCC(setnc)
+FOP_SETCC(setz)
+FOP_SETCC(setnz)
+FOP_SETCC(setbe)
+FOP_SETCC(setnbe)
+FOP_SETCC(sets)
+FOP_SETCC(setns)
+FOP_SETCC(setp)
+FOP_SETCC(setnp)
+FOP_SETCC(setl)
+FOP_SETCC(setnl)
+FOP_SETCC(setle)
+FOP_SETCC(setnle)
+FOP_END;
+
#define __emulate_1op_rax_rdx(ctxt, _op, _suffix, _ex) \
do { \
unsigned long _tmp; \
@@ -939,39 +961,15 @@ static int read_descriptor(struct x86_emulate_ctxt *ctxt,
return rc;
}
-static int test_cc(unsigned int condition, unsigned int flags)
+static u8 test_cc(unsigned int condition, unsigned long flags)
{
- int rc = 0;
+ u8 rc;
+ void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
- switch ((condition & 15) >> 1) {
- case 0: /* o */
- rc |= (flags & EFLG_OF);
- break;
- case 1: /* b/c/nae */
- rc |= (flags & EFLG_CF);
- break;
- case 2: /* z/e */
- rc |= (flags & EFLG_ZF);
- break;
- case 3: /* be/na */
- rc |= (flags & (EFLG_CF|EFLG_ZF));
- break;
- case 4: /* s */
- rc |= (flags & EFLG_SF);
- break;
- case 5: /* p/pe */
- rc |= (flags & EFLG_PF);
- break;
- case 7: /* le/ng */
- rc |= (flags & EFLG_ZF);
- /* fall through */
- case 6: /* l/nge */
- rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF));
- break;
- }
-
- /* Odd condition identifiers (lsb == 1) have inverted sense. */
- return (!!rc ^ (condition & 1));
+ flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
+ asm("pushq %[flags]; popf; call *%[fastop]"
+ : "=a"(rc) : [fastop]"r"(fop), [flags]"r"(flags));
+ return rc;
}
static void fetch_register_operand(struct operand *op)
--
1.8.0.2
--
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