diff mbox series

qmp: fix aio_poll() assertion failure on Windows

Message ID 20201021064033.8600-1-vr_qemu@t-online.de
State Accepted
Commit eada6d9220b77ffee13a86ca8a7aba8fc4451e71
Headers show
Series qmp: fix aio_poll() assertion failure on Windows | expand

Commit Message

Volker Rümelin Oct. 21, 2020, 6:40 a.m. UTC
Commit 9ce44e2ce2 "qmp: Move dispatcher to a coroutine" modified
aio_poll() in util/aio-posix.c to avoid an assertion failure. This
change is missing in util/aio-win32.c.

Apply the changes to util/aio-posix.c to util/aio-win32.c too.
This fixes an assertion failure on Windows whenever QEMU exits.

$ ./qemu-system-x86_64.exe -machine pc,accel=tcg -display gtk
**
ERROR:../qemu/util/aio-win32.c:337:aio_poll: assertion failed:
(in_aio_context_home_thread(ctx))
Bail out! ERROR:../qemu/util/aio-win32.c:337:aio_poll: assertion
failed: (in_aio_context_home_thread(ctx))

Fixes: 9ce44e2ce2 ("qmp: Move dispatcher to a coroutine")
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
---
 util/aio-win32.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Stefan Hajnoczi Oct. 21, 2020, 2:51 p.m. UTC | #1
On Wed, Oct 21, 2020 at 08:40:33AM +0200, Volker Rümelin wrote:
> Commit 9ce44e2ce2 "qmp: Move dispatcher to a coroutine" modified

> aio_poll() in util/aio-posix.c to avoid an assertion failure. This

> change is missing in util/aio-win32.c.

> 

> Apply the changes to util/aio-posix.c to util/aio-win32.c too.

> This fixes an assertion failure on Windows whenever QEMU exits.

> 

> $ ./qemu-system-x86_64.exe -machine pc,accel=tcg -display gtk

> **

> ERROR:../qemu/util/aio-win32.c:337:aio_poll: assertion failed:

> (in_aio_context_home_thread(ctx))

> Bail out! ERROR:../qemu/util/aio-win32.c:337:aio_poll: assertion

> failed: (in_aio_context_home_thread(ctx))

> 

> Fixes: 9ce44e2ce2 ("qmp: Move dispatcher to a coroutine")

> Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>

> ---

>  util/aio-win32.c | 8 +++++++-

>  1 file changed, 7 insertions(+), 1 deletion(-)


Thanks, applied to my block-next tree:
https://gitlab.com/stefanha/qemu/commits/block-next

Stefan
Mark Cave-Ayland Nov. 2, 2020, 12:50 p.m. UTC | #2
On 21/10/2020 07:40, Volker Rümelin wrote:

> Commit 9ce44e2ce2 "qmp: Move dispatcher to a coroutine" modified

> aio_poll() in util/aio-posix.c to avoid an assertion failure. This

> change is missing in util/aio-win32.c.

> 

> Apply the changes to util/aio-posix.c to util/aio-win32.c too.

> This fixes an assertion failure on Windows whenever QEMU exits.

> 

> $ ./qemu-system-x86_64.exe -machine pc,accel=tcg -display gtk

> **

> ERROR:../qemu/util/aio-win32.c:337:aio_poll: assertion failed:

> (in_aio_context_home_thread(ctx))

> Bail out! ERROR:../qemu/util/aio-win32.c:337:aio_poll: assertion

> failed: (in_aio_context_home_thread(ctx))

> 

> Fixes: 9ce44e2ce2 ("qmp: Move dispatcher to a coroutine")

> Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>

> ---

>   util/aio-win32.c | 8 +++++++-

>   1 file changed, 7 insertions(+), 1 deletion(-)

> 

> diff --git a/util/aio-win32.c b/util/aio-win32.c

> index e7b1d649e9..168717b51b 100644

> --- a/util/aio-win32.c

> +++ b/util/aio-win32.c

> @@ -18,6 +18,7 @@

>   #include "qemu/osdep.h"

>   #include "qemu-common.h"

>   #include "block/block.h"

> +#include "qemu/main-loop.h"

>   #include "qemu/queue.h"

>   #include "qemu/sockets.h"

>   #include "qapi/error.h"

> @@ -333,8 +334,13 @@ bool aio_poll(AioContext *ctx, bool blocking)

>        * There cannot be two concurrent aio_poll calls for the same AioContext (or

>        * an aio_poll concurrent with a GSource prepare/check/dispatch callback).

>        * We rely on this below to avoid slow locked accesses to ctx->notify_me.

> +     *

> +     * aio_poll() may only be called in the AioContext's thread. iohandler_ctx

> +     * is special in that it runs in the main thread, but that thread's context

> +     * is qemu_aio_context.

>        */

> -    assert(in_aio_context_home_thread(ctx));

> +    assert(in_aio_context_home_thread(ctx == iohandler_get_aio_context() ?

> +                                      qemu_get_aio_context() : ctx));

>       progress = false;

>   

>       /* aio_notify can avoid the expensive event_notifier_set if


Sorry about the delay, however I've just tried this on top of git master and it fixes 
the problem with the assert() when exiting QEMU on Win32 so:

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>


Is it possible to get this merged for 5.2?


ATB,

Mark.
diff mbox series

Patch

diff --git a/util/aio-win32.c b/util/aio-win32.c
index e7b1d649e9..168717b51b 100644
--- a/util/aio-win32.c
+++ b/util/aio-win32.c
@@ -18,6 +18,7 @@ 
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "block/block.h"
+#include "qemu/main-loop.h"
 #include "qemu/queue.h"
 #include "qemu/sockets.h"
 #include "qapi/error.h"
@@ -333,8 +334,13 @@  bool aio_poll(AioContext *ctx, bool blocking)
      * There cannot be two concurrent aio_poll calls for the same AioContext (or
      * an aio_poll concurrent with a GSource prepare/check/dispatch callback).
      * We rely on this below to avoid slow locked accesses to ctx->notify_me.
+     *
+     * aio_poll() may only be called in the AioContext's thread. iohandler_ctx
+     * is special in that it runs in the main thread, but that thread's context
+     * is qemu_aio_context.
      */
-    assert(in_aio_context_home_thread(ctx));
+    assert(in_aio_context_home_thread(ctx == iohandler_get_aio_context() ?
+                                      qemu_get_aio_context() : ctx));
     progress = false;
 
     /* aio_notify can avoid the expensive event_notifier_set if