Hi,

Can anyone reproduce the failure of one troublesome test
vhost-user/flags-mismatch (https://wiki.qemu.org/Testing/CI/TroublesomeTests)
which has been disabled since Aug 15 2017 (
https://patchwork.kernel.org/patch/9939431/)?  Last month I downloaded QEMU
source code (commit ID: 3483534ec3) and this version also failed this test.
After debugging this issue, I thought I have fixed this issue by saving
acknowledged features after vhost backend disconnect with the client
(qemu). But later I reviewed the commit history of net/vhost-user.c and
found out this test failed on my machines because of  a newly introduced
bug from a recent commit (https://patchwork.kernel.org/patch/11054781/) on
July 29 2019 and this new bug has already been fixed by a more recent
commit (
https://lists.sr.ht/~philmd/qemu/%3C20190924162044.11414-1-amorenoz%40redhat.com%3E).
After more investigation, it surprised me both 3.1.0 and 2.9.1could pass
vhost-user/flags-mismatch test. According to the comments on the commit
https://patchwork.kernel.org/patch/9939431/ which disabled the
vhost-user/flags-mismatch and other two tests, it seems the tests are only
broken on travis. Maybe we should re-investigate this issue to re-enable
the test so similar bugs like
https://bugzilla.redhat.com/show_bug.cgi?id=1738768 could be prevented in
the first place.

Btw we can excluisvely check this test on latest QEMU by given TESTPATH and
setting QTEST_VHOST_USER_FIXME environment variable,
    QTEST_VHOST_USER_FIXME=1
QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64 QTEST_QEMU_IMG=qemu-img
tests/qos-test -p
/x86_64/pc/i440FX-pcihost/pci-bus-pc/pci-bus/virtio-net-pci/virtio-net/virtio-net-tests/vhost-user/flags-mismatch


-- 
*Best regards,*
*Coiby*