[PATCH net-next] netdevsim: 'support' multi-buf XDP

[Jakub Kicinski <kuba@kernel.org>]

Don't error out on large MTU if XDP is multi-buf.
The ping test now tests ping with XDP and high MTU.
netdevsim doesn't actually run the prog (yet?) so
it doesn't matter if the prog was multi-buf..

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/netdevsim/bpf.c    | 3 ++-
 drivers/net/netdevsim/netdev.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c
index 608953d4f98d..49537d3c4120 100644
--- a/drivers/net/netdevsim/bpf.c
+++ b/drivers/net/netdevsim/bpf.c
@@ -296,7 +296,8 @@ static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
 		NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv");
 		return -EINVAL;
 	}
-	if (ns->netdev->mtu > NSIM_XDP_MAX_MTU) {
+	if (bpf->prog && !bpf->prog->aux->xdp_has_frags &&
+	    ns->netdev->mtu > NSIM_XDP_MAX_MTU) {
 		NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled");
 		return -EINVAL;
 	}
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index d71fd2907cc8..a5e5e064927d 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -116,7 +116,8 @@ static int nsim_change_mtu(struct net_device *dev, int new_mtu)
 {
 	struct netdevsim *ns = netdev_priv(dev);
 
-	if (ns->xdp.prog && new_mtu > NSIM_XDP_MAX_MTU)
+	if (ns->xdp.prog && !ns->xdp.prog->aux->xdp_has_frags &&
+	    new_mtu > NSIM_XDP_MAX_MTU)
 		return -EBUSY;
 
 	WRITE_ONCE(dev->mtu, new_mtu);
-- 
2.48.1