main: force enabling of I/O thread

Enabling the I/O thread by default seems like an important part of declaring
1.0.  Besides allowing true SMP support with KVM, the I/O thread means that the
TCG VCPU doesn't have to multiplex itself with the I/O dispatch routines which
currently requires a (racey) signal based alarm system.

I know there have been concerns about performance.  I think so far the ones that
have come up (virtio-net) are most likely due to secondary reasons like
decreased batching.

I think we ought to force enabling I/O thread early in 1.0 development and
commit to resolving any lingering issues.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 0 insertions, 18 deletions

diff --git a/vl.c b/vl.c
index 60bce0cc71..7a6fbacee5 100644
--- a/vl.c
+++ b/vl.c
@@ -1445,17 +1445,6 @@ int main_loop_wait(int nonblocking)
     return ret;
 }
 
-#ifndef CONFIG_IOTHREAD
-static int vm_request_pending(void)
-{
-    return powerdown_requested ||
-           reset_requested ||
-           shutdown_requested ||
-           debug_requested ||
-           vmstop_requested;
-}
-#endif
-
 qemu_irq qemu_system_powerdown;
 
 static void main_loop(void)
@@ -1470,14 +1459,7 @@ static void main_loop(void)
     qemu_main_loop_start();
 
     for (;;) {
-#ifdef CONFIG_IOTHREAD
         nonblocking = !kvm_enabled() && last_io > 0;
-#else
-        nonblocking = cpu_exec_all();
-        if (vm_request_pending()) {
-            nonblocking = true;
-        }
-#endif
 #ifdef CONFIG_PROFILER
         ti = profile_getclock();
 #endif