net: Introduce NetClientInfo.check_peer_type()

Some network backends (vhost-user and vhost-vdpa) work only with
specific devices. At startup, they second guess what the command line
option handling will do and error out if they think 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.

Add a callback where backends can check compatibility with a device when
it actually tries to attach, even on hotplug.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20211008133442.141332-2-kwolf@redhat.com>
Reviewed-by: Damien Hedde <damien.hedde@greensocs.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2021-10-08 15:34:28 +02:00
parent 4d1a525dfa
commit e287bf7bb1
2 changed files with 8 additions and 0 deletions

View File

@ -431,6 +431,12 @@ static void set_netdev(Object *obj, Visitor *v, const char *name,
goto out;
}
if (peers[i]->info->check_peer_type) {
if (!peers[i]->info->check_peer_type(peers[i], obj->class, errp)) {
goto out;
}
}
ncs[i] = peers[i];
ncs[i]->queue_index = i;
}

View File

@ -62,6 +62,7 @@ typedef struct SocketReadState SocketReadState;
typedef void (SocketReadStateFinalize)(SocketReadState *rs);
typedef void (NetAnnounce)(NetClientState *);
typedef bool (SetSteeringEBPF)(NetClientState *, int);
typedef bool (NetCheckPeerType)(NetClientState *, ObjectClass *, Error **);
typedef struct NetClientInfo {
NetClientDriver type;
@ -84,6 +85,7 @@ typedef struct NetClientInfo {
SetVnetBE *set_vnet_be;
NetAnnounce *announce;
SetSteeringEBPF *set_steering_ebpf;
NetCheckPeerType *check_peer_type;
} NetClientInfo;
struct NetClientState {