On Fri, Apr 06, 2018 at 01:51:25PM -0500, Brijesh Singh wrote: > 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 <m...@redhat.com> > Cc: Jason Wang <jasow...@redhat.com> > Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com> > --- > > Changes since v1: > - use qemu_set_nonblock() instead of fcntl(..) > > net/tap.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/tap.c b/net/tap.c > index 2b3a36f9b50d..89c4e19162a2 100644 > --- a/net/tap.c > +++ b/net/tap.c > @@ -40,6 +40,7 @@ > #include "qemu-common.h" > #include "qemu/cutils.h" > #include "qemu/error-report.h" > +#include "qemu/sockets.h" > > #include "net/tap.h" > > @@ -693,6 +694,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap, > NetClientState *peer, > } > return; > } > + qemu_set_nonblock(vhostfd); > } else { > vhostfd = open("/dev/vhost-net", O_RDWR); > if (vhostfd < 0) { > -- > 2.14.3