[Qemu-devel] [QEMU-2.8] Source QEMU crashes with: "bdrv_co_pwritev: Assertion `!(bs->open_flags & BDRV_O_INACTIVE)' failed"

[Kashyap Chamarthy]

I have seen a bunch of reports about this assertion error (on source
QEMU).  [At least I recall Greg Kurz mentioning this a week or so ago on
#qemu, OFTC.]

I just noticed this crash in upstream OpenStack CI environment.  This
seems to occur (only intermittently, though) during live migration
without shared-storage.

[I've attached the complete source and destination QEMU command-line in
a separate plain text file.]

But here are the errors from source and destination QEMU:

Source QEMU:
-----------------------------------------------------------------------
[...]
2017-04-21 13:54:08.505+0000: initiating migration
qemu-system-x86_64: /build/qemu-5OJ39u/qemu-2.8+dfsg/block/io.c:1514: 
bdrv_co_pwritev: Assertion `!(bs->open_flags & BDRV_O_INACTIVE)' failed.
2017-04-21 13:54:08.791+0000: shutting down, reason=crashed
-----------------------------------------------------------------------

Destination QEMU:
-----------------------------------------------------------------------
[...]
/build/qemu-5OJ39u/qemu-2.8+dfsg/nbd/server.c:nbd_receive_request():L710: read 
failed
2017-04-21 13:54:08.792+0000: shutting down, reason=failed
2017-04-21T13:54:08.793259Z qemu-system-x86_64: terminating on signal 15 from 
pid 12160 (/usr/sbin/libvirtd)
-----------------------------------------------------------------------

Any hints as how to how to deal with this in QEMU 2.8?

FWIW, the upstream OpenStack CI only very recently moved to QEMU 2.8, so
it is unlikely that the CI env will move to the just-released 2.9
anytime soon.  (But there's work in progress to create a CI job that
tests with QEMU 2.9.)

-- 
/kashyap

QEMU-command-line-for-source-and-dest-bdrv_co_pwritev.txt
Description: Text document