On Fri, Aug 08, 2025 at 10:08:17AM +0200, Markus Armbruster wrote:
> net_slirp_register_poll_sock() and net_slirp_unregister_poll_sock()
> report WSAEventSelect() failure with error_setg(&error_warn, ...).
>
> I'm not familiar with liblirp, so I can't say whether the network
^^^^^^^^^ 'libslirp'
> backend will work after such a failure. If it doesn't, then this
> should be an error. If it does, then why bother the user with a
> warning that isn't actionable, and likely confusing?
>
> Regardless of that, error_setg_win32(&error_warn, ...) is undesirable
> just like error_setg(&error_fatal, ...) and error_setg(&error_abort,
> ...) are. Replace by warn_report().
>
> Cc: Marc-André Lureau <marcandre.lur...@redhat.com>
> Signed-off-by: Markus Armbruster <arm...@redhat.com>
> --->
net/slirp.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
Reviewed-by: Daniel P. Berrangé <berra...@redhat.com>
> diff --git a/net/slirp.c b/net/slirp.c
> index 9657e86a84..d75b09f16b 100644
> --- a/net/slirp.c
> +++ b/net/slirp.c
> @@ -262,7 +262,8 @@ static void net_slirp_register_poll_sock(slirp_os_socket
> fd, void *opaque)
> if (WSAEventSelect(fd, event_notifier_get_handle(&ctxt->notifier),
> FD_READ | FD_ACCEPT | FD_CLOSE |
> FD_CONNECT | FD_WRITE | FD_OOB) != 0) {
> - error_setg_win32(&error_warn, WSAGetLastError(), "failed to
> WSAEventSelect()");
> + warn_report("failed to WSAEventSelect(): %s",
> + g_win32_error_message(WSAGetLastError()));
> }
> #endif
IMHO this one ought to be considered fatal. If we can't select the
right events on the socket, then we're not going to have a good time
trying to poll on events. The libslirp callback API doesn't allow
us to return a success/failure code from this function, and IMHO it
is not appropriate to use error_fatal here because a fault with slirp
should not take down the whole of QEMU. So warn_report is the least
worst option I guess. At least it is a hint to the user that all is
not well - even if they can't action it, it might alert them if they
see network problems in their guest.
> }
> @@ -271,7 +272,8 @@ static void
> net_slirp_unregister_poll_sock(slirp_os_socket fd, void *opaque)
> {
> #ifdef WIN32
> if (WSAEventSelect(fd, NULL, 0) != 0) {
> - error_setg_win32(&error_warn, WSAGetLastError(), "failed to
> WSAEventSelect()");
> + warn_report("failed to WSAEventSelect()",
> + g_win32_error_message(WSAGetLastError()));
> }
This one is reasonable to treat as non-fatal, since once we've
unregistered the socket for polling
> #endif
> }
> --
> 2.49.0
>
>
With regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
