A guest boot hangs while probing the network interface when
iommu_platform=on is used.
The following qemu cli hangs without this patch:
# $QEMU \
-netdev tap,fd=3,id=hostnet0,vhost=on,vhostfd=4 3<>/dev/tap67
4<>/dev/host-net \
-device
virtio-net-pci,netdev=hostnet0,id=net0,iommu_platform=on,disable-legacy=on \
...
Commit: c471ad0e9bd46 (vhost_net: device IOTLB support) took care of
setting vhostfd to non-blocking when QEMU opens /dev/host-net but if
the fd is passed from qemu cli then we need to ensure that fd is set
to non-blocking.
Fixes: c471ad0e9bd46 "vhost_net: device IOTLB support"
Cc: Michael S. Tsirkin <address@hidden>
Cc: Jason Wang <address@hidden>
Signed-off-by: Brijesh Singh <address@hidden>
---
net/tap.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/tap.c b/net/tap.c
index 2b3a36f9b50d..8c026fbf95cd 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -693,6 +693,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap,
NetClientState *peer,
}
return;
}
+ fcntl(vhostfd, F_SETFL, O_NONBLOCK);