Re: [Qemu-devel] ivshmem assertion failure with EventNotifier

[Jan Kiszka <jan.kiszka@web.de>]

[-- Attachment #1: Type: text/plain, Size: 1205 bytes --]

On 2012-08-22 06:29, Cam Macdonell wrote:
> Hi Paolo,
> 
> I've noticed an assertion error when sending interrupts via ivshmem.
> I bisected to this patch.
> 
> commit 563027cc0c94aa4846c18f9d665a4c90f8c42ba8
> Author: Paolo Bonzini <pbonzini@redhat.com>
> Date:   Thu Jul 5 17:16:25 2012 +0200
> 
>     ivshmem: use EventNotifier and memory API
> 
>     All of ivshmem's usage of eventfd now has a corresponding API in
>     EventNotifier.  Simplify the code by using it, and also use the
>     memory API consistently to set up and tear down the ioeventfds.
> 
>     Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>     Signed-off-by: Avi Kivity <avi@redhat.com>
> 
> qemu-system-x86_64: /home/cam/src/git/qemu/memory.c:1244: memory_region_del_even
> tfd: Assertion `i != mr->ioeventfd_nb' failed.  This assertion failure
> occurs when the eventfd is triggered.
> 
> I'll continue to dig around, but can you explain what this assertion
> is catching.  Is there an initialization that might be missing?

Possibly a double-release of the eventfd. The assertion checks if the
parameters provided on del_eventfd match an existing one. Or that
matching is broken.

Jan



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 262 bytes --]