[PULL 0/1] virtio: regression fix

[PULL 0/1] virtio: regression fix

[Michael S. Tsirkin]

The following changes since commit a0d7215e339b61c7d7a7b3fcf754954d80d93eb8:

  vhost-vdpa: do not cleanup the vdpa/vhost-net structures if peer nic is present (2023-06-26 09:50:00 -0400)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream

for you to fetch changes up to 0585e97f070014265e5ec3b28d27dcb963cde25b:

  net/vhost-net: do not assert on null pointer return from tap_get_vhost_net() (2023-06-28 07:38:59 -0400)

----------------------------------------------------------------
virtio: regression fix

A regression was introduced in the last pull request. Fix it up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

----------------------------------------------------------------
Ani Sinha (1):
      net/vhost-net: do not assert on null pointer return from tap_get_vhost_net()

 hw/net/vhost_net.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

[PULL 1/1] net/vhost-net: do not assert on null pointer return from tap_get_vhost_net()

[Michael S. Tsirkin]

From: Ani Sinha <anisinha@redhat.com>

When 'vhost=off' or no vhost specific options at all are passed for the tap
net-device backend, tap_get_vhost_net() can return NULL. The function
net_init_tap_one() does not call vhost_net_init() on such cases and therefore
vhost_net pointer within the tap device state structure remains NULL. Hence,
assertion here on a NULL pointer return from tap_get_vhost_net() would not be
correct. Remove it and fix the crash generated by qemu upon initialization in
the following call chain :

qdev_realize() -> pci_qdev_realize() -> virtio_device_realize() ->
virtio_bus_device_plugged() -> virtio_net_get_features() -> get_vhost_net()

Fixes: 0e994668d00c9c ("vhost_net: add an assertion for TAP client backends")
Reported-by: Cédric Le Goater <clg@redhat.com>
Report: <abab7a71-216d-b103-fa47-70bdf9dc0080@redhat.com>
Signed-off-by: Ani Sinha <anisinha@redhat.com>
Message-Id: <20230628112804.36676-1-anisinha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/net/vhost_net.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 6db23ca323..6b958d6363 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -507,7 +507,12 @@ VHostNetState *get_vhost_net(NetClientState *nc)
     switch (nc->info->type) {
     case NET_CLIENT_DRIVER_TAP:
         vhost_net = tap_get_vhost_net(nc);
-        assert(vhost_net);
+        /*
+         * tap_get_vhost_net() can return NULL if a tap net-device backend is
+         * created with 'vhost=off' option, 'vhostforce=off' or no vhost or
+         * vhostforce or vhostfd options at all. Please see net_init_tap_one().
+         * Hence, we omit the assertion here.
+         */
         break;
 #ifdef CONFIG_VHOST_NET_USER
     case NET_CLIENT_DRIVER_VHOST_USER:
-- 
MST

Re: [PULL 0/1] virtio: regression fix

[Michael S. Tsirkin]

On Wed, Jun 28, 2023 at 07:41:34AM -0400, Michael S. Tsirkin wrote:
> The following changes since commit a0d7215e339b61c7d7a7b3fcf754954d80d93eb8:
> 
>   vhost-vdpa: do not cleanup the vdpa/vhost-net structures if peer nic is present (2023-06-26 09:50:00 -0400)
> 
> are available in the Git repository at:
> 
>   https://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream
> 
> for you to fetch changes up to 0585e97f070014265e5ec3b28d27dcb963cde25b:

ca3fcdeeeef56f46a7ac7b2408eda608d59be6f1 now - added reviewed by tags.

>   net/vhost-net: do not assert on null pointer return from tap_get_vhost_net() (2023-06-28 07:38:59 -0400)
> 
> ----------------------------------------------------------------
> virtio: regression fix
> 
> A regression was introduced in the last pull request. Fix it up.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> 
> ----------------------------------------------------------------
> Ani Sinha (1):
>       net/vhost-net: do not assert on null pointer return from tap_get_vhost_net()
> 
>  hw/net/vhost_net.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 

Re: [PULL 0/1] virtio: regression fix

[Richard Henderson]

On 6/28/23 13:41, Michael S. Tsirkin wrote:
> The following changes since commit a0d7215e339b61c7d7a7b3fcf754954d80d93eb8:
> 
>    vhost-vdpa: do not cleanup the vdpa/vhost-net structures if peer nic is present (2023-06-26 09:50:00 -0400)
> 
> are available in the Git repository at:
> 
>    https://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git  tags/for_upstream
> 
> for you to fetch changes up to 0585e97f070014265e5ec3b28d27dcb963cde25b:
> 
>    net/vhost-net: do not assert on null pointer return from tap_get_vhost_net() (2023-06-28 07:38:59 -0400)
> 
> ----------------------------------------------------------------
> virtio: regression fix
> 
> A regression was introduced in the last pull request. Fix it up.
> 
> Signed-off-by: Michael S. Tsirkin<mst@redhat.com>

Applied, thanks.  Please update https://wiki.qemu.org/ChangeLog/8.1 as appropriate.


r~