Re: [Qemu-devel] [PATCH for-2.12] tap: set vhostfd passed from qemu cli to non-blocking
On Fri, Apr 06, 2018 at 07:03:56AM -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
> Cc: Jason Wang
> Signed-off-by: Brijesh Singh
Reviewed-by: Michael S. Tsirkin
> ---
> 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);
> } else {
> vhostfd = open("/dev/vhost-net", O_RDWR);
> if (vhostfd < 0) {
> --
> 2.14.3
Re: [Qemu-devel] [PATCH for-2.12] tap: set vhostfd passed from qemu cli to non-blocking
On 04/06/2018 10:44 AM, Eric Blake wrote: On 04/06/2018 07:03 AM, 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 Cc: Jason Wang Signed-off-by: Brijesh Singh --- 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); Please use qemu_set_nonblock() instead. Sure will do.
Re: [Qemu-devel] [PATCH for-2.12] tap: set vhostfd passed from qemu cli to non-blocking
On 04/06/2018 07:03 AM, 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 > Cc: Jason Wang > Signed-off-by: Brijesh Singh > --- > 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); Please use qemu_set_nonblock() instead. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org signature.asc Description: OpenPGP digital signature
[Qemu-devel] [PATCH for-2.12] tap: set vhostfd passed from qemu cli to non-blocking
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
Cc: Jason Wang
Signed-off-by: Brijesh Singh
---
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);
} else {
vhostfd = open("/dev/vhost-net", O_RDWR);
if (vhostfd < 0) {
--
2.14.3
