KVM: x86 emulator: move string instruction completion check into separate function

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 24 insertions, 13 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 42d42ca2c37b..3dcbc1d0a59d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2933,6 +2933,28 @@ done:
         return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
 }
 
+static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
+{
+        struct decode_cache *c = &ctxt->decode;
+
+        /* The second termination condition only applies for REPE
+         * and REPNE. Test if the repeat string operation prefix is
+         * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
+         * corresponding termination condition according to:
+         *      - if REPE/REPZ and ZF = 0 then done
+         *      - if REPNE/REPNZ and ZF = 1 then done
+         */
+        if (((c->b == 0xa6) || (c->b == 0xa7) ||
+             (c->b == 0xae) || (c->b == 0xaf))
+            && (((c->rep_prefix == REPE_PREFIX) &&
+                 ((ctxt->eflags & EFLG_ZF) == 0))
+                || ((c->rep_prefix == REPNE_PREFIX) &&
+                    ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))))
+                return true;
+
+        return false;
+}
+
 int
 x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 {
@@ -3423,19 +3445,8 @@ writeback:
         if (c->rep_prefix && (c->d & String)) {
                 struct read_cache *r = &ctxt->decode.io_read;
                 register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1);
-                /* The second termination condition only applies for REPE
-                 * and REPNE. Test if the repeat string operation prefix is
-                 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
-                 * corresponding termination condition according to:
-                 *      - if REPE/REPZ and ZF = 0 then done
-                 *      - if REPNE/REPNZ and ZF = 1 then done
-                 */
-                if (((c->b == 0xa6) || (c->b == 0xa7) ||
-                     (c->b == 0xae) || (c->b == 0xaf))
-                    && (((c->rep_prefix == REPE_PREFIX) &&
-                         ((ctxt->eflags & EFLG_ZF) == 0))
-                        || ((c->rep_prefix == REPNE_PREFIX) &&
-                            ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))))
+
+                if (string_insn_completed(ctxt))
                         ctxt->restart = false;
                 /*
                  * Re-enter guest when pio read ahead buffer is empty or,