On 10/8/21 15:34, Kevin Wolf wrote:
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@xxxxxxxxxx>
Reviewed-by: Damien Hedde <damien.hedde@xxxxxxxxxxxxx>
---
include/net/net.h | 2 ++
hw/core/qdev-properties-system.c | 6 ++++++
2 files changed, 8 insertions(+)
diff --git a/include/net/net.h b/include/net/net.h
index 5d1508081f..986288eb07 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -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 {
diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index e71f5d64d1..a91f60567a 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -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;
}
