linux-toradex.git/drivers/net/virtio_net.c, branch v6.9

virtio_net: Do not send RSS key if it is not supported

2024-04-07T14:43:14+00:00

There is a bug when setting the RSS options in virtio_net that can break
the whole machine, getting the kernel into an infinite loop.

Running the following command in any QEMU virtual machine with virtionet
will reproduce this problem:

    # ethtool -X eth0  hfunc toeplitz

This is how the problem happens:

1) ethtool_set_rxfh() calls virtnet_set_rxfh()

2) virtnet_set_rxfh() calls virtnet_commit_rss_command()

3) virtnet_commit_rss_command() populates 4 entries for the rss
scatter-gather

4) Since the command above does not have a key, then the last
scatter-gatter entry will be zeroed, since rss_key_size == 0.
sg_buf_size = vi->rss_key_size;

5) This buffer is passed to qemu, but qemu is not happy with a buffer
with zero length, and do the following in virtqueue_map_desc() (QEMU
function):

  if (!sz) {
      virtio_error(vdev, "virtio: zero sized buffers are not allowed");

6) virtio_error() (also QEMU function) set the device as broken

    vdev->broken = true;

7) Qemu bails out, and do not repond this crazy kernel.

8) The kernel is waiting for the response to come back (function
virtnet_send_command())

9) The kernel is waiting doing the following :

      while (!virtqueue_get_buf(vi->cvq, &tmp) &&
	     !virtqueue_is_broken(vi->cvq))
	      cpu_relax();

10) None of the following functions above is true, thus, the kernel
loops here forever. Keeping in mind that virtqueue_is_broken() does
not look at the qemu `vdev->broken`, so, it never realizes that the
vitio is broken at QEMU side.

Fix it by not sending RSS commands if the feature is not available in
the device.

Fixes: c7114b1249fa ("drivers/net/virtio_net: Added basic RSS support.")
Cc: stable@vger.kernel.org
Cc: qemu-devel@nongnu.org
Signed-off-by: Breno Leitao 
Reviewed-by: Heng Qi 
Reviewed-by: Xuan Zhuo 
Signed-off-by: David S. Miller

virtio_net: rename free_old_xmit_skbs to free_old_xmit

2024-03-19T07:19:22+00:00

Since free_old_xmit_skbs not only deals with skb, but also xdp frame and
subsequent added xsk, so change the name of this function to
free_old_xmit.

Signed-off-by: Xuan Zhuo 
Acked-by: Jason Wang 
Message-Id: <20240229072044.77388-19-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin

virtio_net: unify the code for recycling the xmit ptr

2024-03-19T07:19:22+00:00

There are two completely similar and independent implementations. This
is inconvenient for the subsequent addition of new types. So extract a
function from this piece of code and call this function uniformly to
recover old xmit ptr.

Signed-off-by: Xuan Zhuo 
Acked-by: Jason Wang 
Message-Id: <20240229072044.77388-18-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin

virtio-net: add cond_resched() to the command waiting loop

2024-03-19T07:19:22+00:00

Adding cond_resched() to the command waiting loop for a better
co-operation with the scheduler. This allows to give CPU a breath to
run other task(workqueue) instead of busy looping when preemption is
not allowed on a device whose CVQ might be slow.

Signed-off-by: Jason Wang 
Message-Id: <20230720083839.481487-3-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Shannon Nelson

virtio-net: convert rx mode setting to use workqueue

2024-03-19T07:19:22+00:00

This patch convert rx mode setting to be done in a workqueue, this is
a must for allow to sleep when waiting for the cvq command to
response since current code is executed under addr spin lock.

Note that we need to disable and flush the workqueue during freeze,
this means the rx mode setting is lost after resuming. This is not the
bug of this patch as we never try to restore rx mode setting during
resume.

Signed-off-by: Jason Wang 
Message-Id: <20230720083839.481487-2-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Shannon Nelson

virtio_net: Fix "‘%d’ directive writing between 1 and 11 bytes into a region of size 10" warnings

2024-01-12T00:54:34+00:00

Fix the warnings when building virtio_net driver.

"
drivers/net/virtio_net.c: In function ‘init_vqs’:
drivers/net/virtio_net.c:4551:48: warning: ‘%d’ directive writing between 1 and 11 bytes into a region of size 10 [-Wformat-overflow=]
 4551 |                 sprintf(vi->rq[i].name, "input.%d", i);
      |                                                ^~
In function ‘virtnet_find_vqs’,
    inlined from ‘init_vqs’ at drivers/net/virtio_net.c:4645:8:
drivers/net/virtio_net.c:4551:41: note: directive argument in the range [-2147483643, 65534]
 4551 |                 sprintf(vi->rq[i].name, "input.%d", i);
      |                                         ^~~~~~~~~~
drivers/net/virtio_net.c:4551:17: note: ‘sprintf’ output between 8 and 18 bytes into a destination of size 16
 4551 |                 sprintf(vi->rq[i].name, "input.%d", i);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/virtio_net.c: In function ‘init_vqs’:
drivers/net/virtio_net.c:4552:49: warning: ‘%d’ directive writing between 1 and 11 bytes into a region of size 9 [-Wformat-overflow=]
 4552 |                 sprintf(vi->sq[i].name, "output.%d", i);
      |                                                 ^~
In function ‘virtnet_find_vqs’,
    inlined from ‘init_vqs’ at drivers/net/virtio_net.c:4645:8:
drivers/net/virtio_net.c:4552:41: note: directive argument in the range [-2147483643, 65534]
 4552 |                 sprintf(vi->sq[i].name, "output.%d", i);
      |                                         ^~~~~~~~~~~
drivers/net/virtio_net.c:4552:17: note: ‘sprintf’ output between 9 and 19 bytes into a destination of size 16
 4552 |                 sprintf(vi->sq[i].name, "output.%d", i);

"

Reviewed-by: Xuan Zhuo 
Signed-off-by: Zhu Yanjun 
Link: https://lore.kernel.org/r/20240104020902.2753599-1-yanjun.zhu@intel.com
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-01-05T02:06:46+00:00

Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  e009b2efb7a8 ("bnxt_en: Remove mis-applied code from bnxt_cfg_ntp_filters()")
  0f2b21477988 ("bnxt_en: Fix compile error without CONFIG_RFS_ACCEL")
https://lore.kernel.org/all/20240105115509.225aa8a2@canb.auug.org.au/

Signed-off-by: Jakub Kicinski

virtio_net: fix missing dma unmap for resize

2024-01-04T00:45:02+00:00

For rq, we have three cases getting buffers from virtio core:

1. virtqueue_get_buf{,_ctx}
2. virtqueue_detach_unused_buf
3. callback for virtqueue_resize

But in commit 295525e29a5b("virtio_net: merge dma operations when
filling mergeable buffers"), I missed the dma unmap for the #3 case.

That will leak some memory, because I did not release the pages referred
by the unused buffers.

If we do such script, we will make the system OOM.

    while true
    do
            ethtool -G ens4 rx 128
            ethtool -G ens4 rx 256
            free -m
    done

Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers")
Signed-off-by: Xuan Zhuo 
Acked-by: Michael S. Tsirkin 
Link: https://lore.kernel.org/r/20231226094333.47740-1-xuanzhuo@linux.alibaba.com
Signed-off-by: Jakub Kicinski

net: ethtool: pass a pointer to parameters to get/set_rxfh ethtool ops

2023-12-14T06:07:16+00:00

The get/set_rxfh ethtool ops currently takes the rxfh (RSS) parameters
as direct function arguments. This will force us to change the API (and
all drivers' functions) every time some new parameters are added.

This is part 1/2 of the fix, as suggested in [1]:

- First simplify the code by always providing a pointer to all params
   (indir, key and func); the fact that some of them may be NULL seems
   like a weird historic thing or a premature optimization.
   It will simplify the drivers if all pointers are always present.

 - Then make the functions take a dev pointer, and a pointer to a
   single struct wrapping all arguments. The set_* should also take
   an extack.

Link: https://lore.kernel.org/netdev/20231121152906.2dd5f487@kernel.org/ [1]
Suggested-by: Jakub Kicinski 
Suggested-by: Jacob Keller 
Signed-off-by: Ahmed Zaki 
Link: https://lore.kernel.org/r/20231213003321.605376-2-ahmed.zaki@intel.com
Signed-off-by: Jakub Kicinski

virtio-net: support rx netdim

2023-12-13T12:49:05+00:00

By comparing the traffic information in the complete napi processes,
let the virtio-net driver automatically adjust the coalescing
moderation parameters of each receive queue.

Signed-off-by: Heng Qi 
Signed-off-by: David S. Miller