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. Additionally, a regression was found during v2, which could have been spotted with a multiqueue test, so add a basic one that would have exhibited the issue. For convenience, the series is also available on: https://github.com/elmarco/qemu, branch vhost-user-reconnect v4: - change notify_migration_done() patch to be VHOST_BACKEND_TYPE_USER specific, to avoid having to handle the case where the backend doesn't implement the callback - change vhost_dev_cleanup() to assert on empty log, instead of adding a call to vhost_log_put() - made "keep vhost_net after a disconnection" more robust, got rid of the acked_features field - improve commit log, and some patch reorganization for clarity v3: - add vhost-user multiqueue test, which would have helped to find the following fix - fix waiting on vhost-user connection with multiqueue (found by Yuanhan Liu) - merge vhost_user_{read,write}() error checking patches - add error reporting to vhost_user_read() (similar to vhost_user_write()) - add a vhost_net_set_backend() wrapper to help with potential crash - some leak fixes v2: - some patch ordering: minor fix, close(fd) fix, assert/fprintf->error_report, check and return error, vhost_dev_cleanup() fixes, keep vhost_net after a disconnect, wait until connection is ready - merge read/write error checks - do not rely on link state to check vhost-user init completed Marc-André Lureau (29): misc: indentation vhost-user: minor simplification vhost: don't assume opaque is a fd, use backend cleanup vhost: make vhost_log_put() idempotent vhost: assert the log was cleaned up vhost: fix cleanup on not fully initialized device vhost: make vhost_dev_cleanup() idempotent vhost-net: always call vhost_dev_cleanup() on failure vhost: fix calling vhost_dev_cleanup() after vhost_dev_init() vhost: do not assert() on vhost_ops failure vhost: use error_report() instead of fprintf(stderr,...) qemu-char: fix qemu_chr_fe_set_msgfds() crash when disconnected vhost-user: call set_msgfds unconditionally vhost-user: check qemu_chr_fe_set_msgfds() return value vhost-user: check vhost_user_{read,write}() return value vhost-user: keep vhost_net after a disconnection vhost-user: add get_vhost_net() assertions Revert "vhost-net: do not crash if backend is not present" vhost-net: vhost_migration_done is vhost-user specific 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 backend init is completed tests: plug some leaks in virtio-net-test tests: fix vhost-user-test leak tests: add /vhost-user/connect-fail test tests: add a simple /vhost-user/multiqueue test vhost-user: add error report in vhost_user_write() vhost: add vhost_net_set_backend() hw/net/vhost_net.c | 34 ++++------- hw/virtio/vhost-user.c | 67 ++++++++++++++------- hw/virtio/vhost.c | 123 +++++++++++++++++++++++--------------- include/hw/virtio/vhost.h | 4 ++ include/sysemu/char.h | 8 +++ net/tap.c | 1 + net/vhost-user.c | 60 +++++++++++-------- qemu-char.c | 82 ++++++++++++++++++-------- tests/Makefile.include | 2 +- tests/vhost-user-test.c | 147 +++++++++++++++++++++++++++++++++++++++++++++- tests/virtio-net-test.c | 12 +++- 11 files changed, 396 insertions(+), 144 deletions(-) -- 2.9.0
