From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Ilya Maximets <i.maximets@ovn.org>, dev@dpdk.org
Cc: Flavio Leitner <fbl@sysclose.org>,
David Marchand <david.marchand@redhat.com>,
Tiwei Bie <tiwei.bie@intel.com>
Subject: Re: [dpdk-dev] [PATCH] vhost: disable host TSO for linear buffers without extbuf
Date: Thu, 24 Oct 2019 12:18:43 +0200 [thread overview]
Message-ID: <4b6e39b6-95b4-6c1b-89db-c7333c738ac1@redhat.com> (raw)
In-Reply-To: <eeacc445-7ef9-2878-b415-e6cb6b571e7c@redhat.com>
On 10/24/19 11:38 AM, Maxime Coquelin wrote:
>
>
> On 10/17/19 5:00 PM, Ilya Maximets wrote:
>> If linear buffers requested and external buffers are not, vhost
>> will not be able to receive any buffer that doesn't fit in a
>> single mbuf. Moreover, if such a buffer will appear in a vring
>> it will never be dequeued and the whole vring will become dead
>> breaking the network connection.
>>
>> Disable segmentation offloading from the host side to avoid
>> having such a big buffers.
>>
>> Cc: Flavio Leitner <fbl@sysclose.org>
>>
>> Fixes: 5005bcda7123 ("vhost: add support for large buffers")
>> Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
>> ---
>>
>> There is still an assumption that users are sane enough to have
>> MTU sized mbufs in a memory pool and that guest will not change
>> MTU to higher values.
>>
>> We, probably, still need to have a check on dequeue path and
>> drop oversized buffers in case of linear buffers to avoid stuck
>> of the virtqueue. Or simply drop support of '+linear -extbuf'
>> case.
>>
>> Note: Only compile tested due to lack of HW.
>>
>> lib/librte_vhost/socket.c | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>
>
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>
> Thanks,
> Maxime
>
Applied to dpdk-next-virtio/master.
Thanks,
Maxime
prev parent reply other threads:[~2019-10-24 10:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-17 15:00 Ilya Maximets
2019-10-24 9:38 ` Maxime Coquelin
2019-10-24 10:18 ` Maxime Coquelin [this message]
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