diff mbox series

[45/99] tap: set vhostfd passed from qemu cli to non-blocking

Message ID 20180723201748.25573-46-mdroth@linux.vnet.ibm.com
State New
Headers show
Series Patch Round-up for stable 2.12.1, freeze on 2018-07-30 | expand

Commit Message

Michael Roth July 23, 2018, 8:16 p.m. UTC 
From: Brijesh Singh <brijesh.singh@amd.com>

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>
(cherry picked from commit d542800d1edc62f63f8a29cfa6bdd1a9536ae11c)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 net/tap.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/net/tap.c b/net/tap.c
index 2b3a36f9b5..89c4e19162 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) {