Re: [PATCH AUTOSEL 4.18 69/88] xen-netfront: fix queue name setting

From: Boris Ostrovsky
Date: Fri Sep 07 2018 - 13:32:50 EST


On 09/06/2018 08:36 PM, Sasha Levin wrote:
> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
>
> [ Upstream commit 2d408c0d4574b01b9ed45e02516888bf925e11a9 ]
>
> Commit f599c64fdf7d ("xen-netfront: Fix race between device setup and
> open") changed the initialization order: xennet_create_queues() now
> happens before we do register_netdev() so using netdev->name in
> xennet_init_queue() is incorrect, we end up with the following in
> /proc/interrupts:
>
> 60: 139 0 xen-dyn -event eth%d-q0-tx
> 61: 265 0 xen-dyn -event eth%d-q0-rx
> 62: 234 0 xen-dyn -event eth%d-q1-tx
> 63: 1 0 xen-dyn -event eth%d-q1-rx
>
> and this looks ugly. Actually, using early netdev name (even when it's
> already set) is also not ideal: nowadays we tend to rename eth devices
> and queue name may end up not corresponding to the netdev name.
>
> Use nodename from xenbus device for queue naming: this can't change in VM's
> lifetime. Now /proc/interrupts looks like
>
> 62: 202 0 xen-dyn -event device/vif/0-q0-tx
> 63: 317 0 xen-dyn -event device/vif/0-q0-rx
> 64: 262 0 xen-dyn -event device/vif/0-q1-tx
> 65: 17 0 xen-dyn -event device/vif/0-q1-rx
>
> Fixes: f599c64fdf7d ("xen-netfront: Fix race between device setup and open")
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> Reviewed-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>


You also want to pull commit 21f2706b20100bb3db378461ab9b8e2035309b5b.

-boris


> ---
> drivers/net/xen-netfront.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
> index 9dd2ca62d84a..5a14b917eee2 100644
> --- a/drivers/net/xen-netfront.c
> +++ b/drivers/net/xen-netfront.c
> @@ -1610,7 +1610,7 @@ static int xennet_init_queue(struct netfront_queue *queue)
> timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
>
> snprintf(queue->name, sizeof(queue->name), "%s-q%u",
> - queue->info->netdev->name, queue->id);
> + queue->info->xbdev->nodename, queue->id);
>
> /* Initialise tx_skbs as a free chain containing every entry. */
> queue->tx_skb_freelist = 0;