[Qemu-devel] [RFC] darwin: work around sigfd

[Alexander Graf]

When running qemu-system on Darwin, the vcpu processes guest code, but
I don't get to see anything on the cocoa screen.

When running a guest with -nographic, time stands still for the guest:

[    0.000000] Detected 2659.508 MHz processor.
[    0.000756] Calibrating delay loop (skipped), value calculated using timer 
frequency.. 5319.01 BogoMIPS (lpj=2659508)
[    0.000999] pid_max: default: 32768 minimum: 301
[    0.000999] Security Framework initialized
[    0.000999] AppArmor: AppArmor initialized
[...]
[    0.000999] Kernel panic - not syncing: IO-APIC + timer doesn't work!  Boot 
with apic=debug and send a report.  Then try booting with the 'noapic' option.
[    0.000999]
[...]
[    0.000999]  [<ffffffff81b3ec92>] kernel_init+0x8f/0x206
[    0.000999]  [<ffffffff81003d74>] kernel_thread_helper+0x4/0x10

This patch makes qemu-system work again on Darwin, but is obviously
just a hack. I'd really like to see some more clever people find out
what exactly is going wrong to find a real solution!

Reported-by: Andreas Färber <address@hidden>
(no signed-off-by on purpose - it's an RFC!)
---
 cpus.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/cpus.c b/cpus.c
index 1fc34b7..ef604bf 100644
--- a/cpus.c
+++ b/cpus.c
@@ -388,6 +388,15 @@ static int qemu_signal_init(void)
     int sigfd;
     sigset_t set;
 
+#ifdef CONFIG_DARWIN
+    /* Darwin breaks for me with sigfd. I don't know why, but it just sits
+       there hanging. The vcpu does process things, so that one's good, but
+       there is no output. Doing the same as win32 works for me. */
+    if (1) {
+        return 0;
+    }
+#endif
+
 #ifdef CONFIG_IOTHREAD
     /* SIGUSR2 used by posix-aio-compat.c */
     sigemptyset(&set);
-- 
1.7.1