vl/cpus: be smarter with icount and MTTCG

The sense of the test was inverted. Make it simple, if icount is
enabled then we disabled MTTCG by default. If the user tries to force
MTTCG upon us then we tell them "no".
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

cpus.c

@@ -181,10 +181,7 @@ static bool check_tcg_memory_orders_compatible(void)
 
 static bool default_mttcg_enabled(void)
 {
-    QemuOpts *icount_opts = qemu_find_opts_singleton("icount");
-    const char *rr = qemu_opt_get(icount_opts, "rr");
-
-    if (rr || TCG_OVERSIZED_GUEST) {
+    if (use_icount || TCG_OVERSIZED_GUEST) {
         return false;
     } else {
 #ifdef TARGET_SUPPORTS_MTTCG
@@ -202,6 +199,8 @@ void qemu_tcg_configure(QemuOpts *opts, Error **errp)
         if (strcmp(t, "multi") == 0) {
             if (TCG_OVERSIZED_GUEST) {
                 error_setg(errp, "No MTTCG when guest word size > hosts");
+            } else if (use_icount) {
+                error_setg(errp, "No MTTCG when icount is enabled");
             } else {
                 if (!check_tcg_memory_orders_compatible()) {
                     error_report("Guest expects a stronger memory ordering "

vl.c

@@ -4055,8 +4055,6 @@ int main(int argc, char **argv, char **envp)
 
     replay_configure(icount_opts);
 
-    qemu_tcg_configure(accel_opts, &error_fatal);
-
     machine_class = select_machine();
 
     set_memory_options(&ram_slots, &maxram_size, machine_class);
@@ -4423,14 +4421,13 @@ int main(int argc, char **argv, char **envp)
         if (!tcg_enabled()) {
             error_report("-icount is not allowed with hardware virtualization");
             exit(1);
-        } else if (qemu_tcg_mttcg_enabled()) {
-            error_report("-icount does not currently work with MTTCG");
-            exit(1);
         }
         configure_icount(icount_opts, &error_abort);
         qemu_opts_del(icount_opts);
     }
 
+    qemu_tcg_configure(accel_opts, &error_fatal);
+
     if (default_net) {
         QemuOptsList *net = qemu_find_opts("net");
         qemu_opts_set(net, NULL, "type", "nic", &error_abort);