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 <address@hidden>
Cc: Jason Wang <address@hidden>
Signed-off-by: Brijesh Singh <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
---
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