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tap: set vhostfd passed from qemu cli to non-blocking

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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: qemu-stable@nongnu.org
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Brijesh Singh 2018-04-06 13:51:25 -05:00 committed by Jason Wang
parent 409c241f88
commit d542800d1e
1 changed files with 2 additions and 0 deletions
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2
net/tap.c
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@ -40,6 +40,7 @@
#include "qemu-common.h" #include "qemu-common.h"
#include "qemu/cutils.h" #include "qemu/cutils.h"
#include "qemu/error-report.h" #include "qemu/error-report.h"
#include "qemu/sockets.h"
#include "net/tap.h" #include "net/tap.h"
@ -693,6 +694,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
} }
return; return;
} }
qemu_set_nonblock(vhostfd);
} else { } else {
vhostfd = open("/dev/vhost-net", O_RDWR); vhostfd = open("/dev/vhost-net", O_RDWR);
if (vhostfd < 0) { if (vhostfd < 0) {