Re: QEMU iotest 267 failure / assertion in migration code

[Thomas Huth]

On 18/01/2023 19.02, Dr. David Alan Gilbert wrote:
> * Thomas Huth (thuth@redhat.com) wrote:
> >   Hi!
> >
> > I just ran "make check" in a build directory where I did
> > not compile qemu-system-x86_64, and got a failure with
> > iotest 267.
> >
> > Re-running the "check" script directly got me some more
> > information:
> >
> > $ ./check -qcow2 267
> > QEMU          -- "/tmp/qemu/tests/qemu-iotests/../../qemu-system-alpha" 
> > -nodefaults -display none -accel qtest
> > QEMU_IMG      -- "/tmp/qemu/tests/qemu-iotests/../../qemu-img"
> > QEMU_IO       -- "/tmp/qemu/tests/qemu-iotests/../../qemu-io" --cache writeback 
> > --aio threads -f qcow2
> > QEMU_NBD      -- "/tmp/qemu/tests/qemu-iotests/../../qemu-nbd"
> > IMGFMT        -- qcow2
> > IMGPROTO      -- file
> > PLATFORM      -- Linux/x86_64 thuth 4.18.0-425.3.1.el8.x86_64
> > TEST_DIR      -- /tmp/qemu/tests/qemu-iotests/scratch
> > SOCK_DIR      -- /tmp/tmp_qbcjhsu
> > GDB_OPTIONS   --
> > VALGRIND_QEMU --
> > PRINT_QEMU_OUTPUT --
> >
> > 267   fail       [18:39:41] [18:39:44]   3.5s                 output mismatch 
> > (see /tmp/qemu/tests/qemu-iotests/scratch/267.out.bad)
> > --- .../qemu/tests/qemu-iotests/267.out
> > +++ /tmp/qemu/tests/qemu-iotests/scratch/267.out.bad
> > @@ -31,23 +31,23 @@
> >   Testing: -drive driver=IMGFMT,file=TEST_DIR/t.IMGFMT,if=none
> >   QEMU X.Y.Z monitor - type 'help' for more information
> >   (qemu) savevm snap0
> > -(qemu) info snapshots
> > -List of snapshots present on all disks:
> > -ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
> > ---        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000
> > -(qemu) loadvm snap0
> > -(qemu) quit
> > +QEMU_PROG: ../../qemu/migration/ram.c:874: pss_find_next_dirty: Assertion 
> > `pss->host_page_end' failed.
>
> I don't understand how that can trigger - it needs investigating as a
> bug.

I've created a ticket so we don't forget:

https://gitlab.com/qemu-project/qemu/-/issues/1456

> > +./common.rc: line 181: 1903770 Aborted                 (core dumped) ( if [ -n 
> > "${QEMU_NEED_PID}" ]; then
> > +    echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid";
> > +fi; GDB=""; if [ -n "${GDB_OPTIONS}" ]; then
> > +    GDB="gdbserver ${GDB_OPTIONS}";
> > +fi; VALGRIND_QEMU="${VALGRIND_QEMU_VM}" _qemu_proc_exec "${VALGRIND_LOGFILE}" $GDB 
> > "$QEMU_PROG" $QEMU_OPTIONS "$@" )
> >
> >
> > Looks like this test does not work if the main machine
> > of the selected QEMU binary does not support migration?
>
> Why doesn't it support migration?

Hmm, maybe I just got that wrong and it's really just the problem that the 
qemu-system-alpha is crashing.

 Thomas