Re: [PATCH v2 02/15] net/vhost-user: Fix device compatibility check

vhost-user works only with specific devices. At startup, it second guesses what the command line option handling will do and error out if it thinks a non-virtio device will attach to them. This second guessing is not only ugly, it can lead to wrong error messages ('-device floppy,netdev=foo' should complain about an unknown property, not about the wrong kind of network device being attached) and completely ignores hotplugging. Drop the old checks and implement .check_peer_type() instead to fix this. As a nice side effect, it also removes one more dependency on the legacy QemuOpts infrastructure and even reduces the code size. Signed-off-by: Kevin Wolf <kwolf(a)redhat.com&gt;

--- net/vhost-user.c | 41 ++++++++++++++--------------------------- 1 file changed, 14 insertions(+), 27 deletions(-) diff --git a/net/vhost-user.c b/net/vhost-user.c index 4a939124d2..b1a0247b59 100644 --- a/net/vhost-user.c +++ b/net/vhost-user.c @@ -198,6 +198,19 @@ static bool vhost_user_has_ufo(NetClientState *nc) return true; } +static bool vhost_user_check_peer_type(NetClientState *nc, ObjectClass *oc, + Error **errp) +{ + const char *driver = object_class_get_name(oc); + + if (!g_str_has_prefix(driver, "virtio-net-")) { + error_setg(errp, "vhost-user requires frontend driver virtio-net-*"); + return false; + } + + return true; +} + static NetClientInfo net_vhost_user_info = { .type = NET_CLIENT_DRIVER_VHOST_USER, .size = sizeof(NetVhostUserState), @@ -207,6 +220,7 @@ static NetClientInfo net_vhost_user_info = { .has_ufo = vhost_user_has_ufo, .set_vnet_be = vhost_user_set_vnet_endianness, .set_vnet_le = vhost_user_set_vnet_endianness, + .check_peer_type = vhost_user_check_peer_type, }; static gboolean net_vhost_user_watch(void *do_not_use, GIOCondition cond, @@ -397,27 +411,6 @@ static Chardev *net_vhost_claim_chardev( return chr; } -static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp) -{ - const char *name = opaque; - const char *driver, *netdev; - - driver = qemu_opt_get(opts, "driver"); - netdev = qemu_opt_get(opts, "netdev"); - - if (!driver || !netdev) { - return 0; - } - - if (strcmp(netdev, name) == 0 && - !g_str_has_prefix(driver, "virtio-net-")) { - error_setg(errp, "vhost-user requires frontend driver virtio-net-*"); - return -1; - } - - return 0; -} - int net_init_vhost_user(const Netdev *netdev, const char *name, NetClientState *peer, Error **errp) { @@ -433,12 +426,6 @@ int net_init_vhost_user(const Netdev *netdev, const char *name, return -1; } - /* verify net frontend */ - if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net, - (char *)name, errp)) { - return -1; - } - queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1; if (queues < 1 || queues > MAX_QUEUE_NUM) { error_setg(errp,