netdev - Re: [PATCH net] tuntap: fix multiqueue rx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20181118.190621.657063282200266660.davem@davemloft.net>
Date:   Sun, 18 Nov 2018 19:06:21 -0800 (PST)
From:   David Miller <davem@...emloft.net>
To:     werekraken@...il.com
Cc:     jasowang@...hat.com, brouer@...hat.com, mst@...hat.com,
        edumazet@...gle.com, sd@...asysnail.net, netdev@...r.kernel.org,
        matthew.cover@...ckpath.com
Subject: Re: [PATCH net] tuntap: fix multiqueue rx

From: Matthew Cover <werekraken@...il.com>
Date: Sun, 18 Nov 2018 00:46:00 -0700

> When writing packets to a descriptor associated with a combined queue, the
> packets should end up on that queue.
> 
> Before this change all packets written to any descriptor associated with a
> tap interface end up on rx-0, even when the descriptor is associated with a
> different queue.
> 
> The rx traffic can be generated by either of the following.
>   1. a simple tap program which spins up multiple queues and writes packets
>      to each of the file descriptors
>   2. tx from a qemu vm with a tap multiqueue netdev
> 
> The queue for rx traffic can be observed by either of the following (done
> on the hypervisor in the qemu case).
>   1. a simple netmap program which opens and reads from per-queue
>      descriptors
>   2. configuring RPS and doing per-cpu captures with rxtxcpu
> 
> Alternatively, if you printk() the return value of skb_get_rx_queue() just
> before each instance of netif_receive_skb() in tun.c, you will get 65535
> for every skb.
> 
> Calling skb_record_rx_queue() to set the rx queue to the queue_index fixes
> the association between descriptor and rx queue.
> 
> Signed-off-by: Matthew Cover <matthew.cover@...ckpath.com>

Applied and queued up for -stable, thanks.