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. 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
