On Tue, Jun 21, 2016 at 12:02:28PM +0200, marcandre.lur...@redhat.com wrote: > From: Marc-André Lureau <marcandre.lur...@redhat.com> > > Hi, > > Since 'vhost-user: simple reconnection support' was merged, it is > possible to disconnect and reconnect a vhost-user backend. However, > many code paths in qemu may trigger assert() when the backend is > disconnected. > > Some assert() could simply be replaced by error_report() or silently > fail since they are recoverable cases. Some missing error checks can > also help prevent later issues. In many cases, the code assumes > get_vhost_net() will be non-NULL after a succesful connection, so I > changed it to stay after a disconnect until the new connection comes > (as suggested by Michael). There are also code paths that are wrong, > see "don't assume opaque is a fd" patch for an example.
Can this be rarranged, first patches fixing the code paths that are wrong, then patches handling the asserts etc? > Since there is feature checks on reconnection, qemu should wait for > the initial connection feature negotiation to complete. The test added > demonstrates this. > > For convenience, the series is also available on: > https://github.com/elmarco/qemu, branch vhost-user-reconnect > > Marc-André Lureau (24): > misc: indentation > vhost-user: minor simplification > qemu-char: check socket is actually connected > vhost-user: check qemu_chr_fe_set_msgfds() return value > vhost: change some assert() for error_report() or silent fail > vhost-user: check vhost_user_write() return value > vhost: use error_report() instead of fprintf(stderr,...) > vhost-user: return a read error > vhost: make vhost_log_put() idempotent > vhost: call vhost_log_put() on cleanup > vhost: add vhost device only after all success > vhost: make vhost_dev_cleanup() idempotent > vhost-net: always call vhost_dev_cleanup() on failure > vhost: don't assume opaque is a fd, use backend cleanup > vhost: fix calling vhost_dev_cleanup() after vhost_dev_init() > vhost-user: keep vhost_net after a disconnection > Revert "vhost-net: do not crash if backend is not present" > get_vhost_net() should be != null after vhost_user_init > vhost-net: success if backend has no ops->vhost_migration_done > vhost: add assert() to check runtime behaviour > char: add chr_wait_connected callback > char: add and use tcp_chr_wait_connected > vhost-user: wait until link is up > tests: add /vhost-user/connect-fail test > > hw/net/vhost_net.c | 19 +++----- > hw/virtio/vhost-user.c | 54 +++++++++++++++-------- > hw/virtio/vhost.c | 114 > +++++++++++++++++++++++++++--------------------- > include/sysemu/char.h | 8 ++++ > net/tap.c | 1 + > net/vhost-user.c | 36 ++++++++------- > qemu-char.c | 82 ++++++++++++++++++++++++---------- > tests/vhost-user-test.c | 37 ++++++++++++++++ > 8 files changed, 233 insertions(+), 118 deletions(-) > > -- > 2.7.4
