From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Li Feng <fengli@smartx.com>
Cc: Chenbo Xia <chenbo.xia@intel.com>, JinYu <jin.yu@intel.com>,
dev <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v1] vhost: add sanity check for resubmiting reqs in split ring
Date: Thu, 14 Oct 2021 13:38:24 +0200 [thread overview]
Message-ID: <1d3701ab-071b-e92c-6e95-639bdff048de@redhat.com> (raw)
In-Reply-To: <CAHckoCwN5WeU+cwNHtjGnWpNdz3Z1ug-NsB5XEu632B9xhG8vg@mail.gmail.com>
On 10/14/21 13:25, Li Feng wrote:
> Thank you for your response.
>
> On Thu, Oct 14, 2021 at 4:17 PM Maxime Coquelin
> <maxime.coquelin@redhat.com> wrote:
>>
>> Hi Li,
>>
>> Adding Jin Yu who introduced this function.
>>
>> On 8/27/21 07:12, Li Feng wrote:
>>> When getting reqs from the avail ring, the id may exceed inflight
>>> queue size. Then the dpdk will crash forever.
>>
>> You need to add Fixes tag and Cc stable@dpdk.org so that it can be
>> backported.
> OK, I will send the v2 version.
>
>>
>>> Signed-off-by: Li Feng <fengli@smartx.com>
>>> ---
>>> lib/vhost/vhost_user.c | 10 ++++++++--
>>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
>>> index 29a4c9af60..f09d0f6a48 100644
>>> --- a/lib/vhost/vhost_user.c
>>> +++ b/lib/vhost/vhost_user.c
>>> @@ -1823,8 +1823,14 @@ vhost_check_queue_inflights_split(struct virtio_net *dev,
>>> last_io = inflight_split->last_inflight_io;
>>>
>>> if (inflight_split->used_idx != used->idx) {
>>> - inflight_split->desc[last_io].inflight = 0;
>>> - rte_atomic_thread_fence(__ATOMIC_SEQ_CST);
>>> + if (unlikely(last_io >= inflight_split->desc_num)) {
>>> + VHOST_LOG_CONFIG(ERR, "last_inflight_io '%"PRIu16"' exceeds inflight "
>>> + "queue size (%"PRIu16").\n", last_io,
>>> + inflight_split->desc_num);
>>
>> If such error happens, shouldn't we return RTE_VHOST_MSG_RESULT_ERR
>> instead of just logging an error?
> I think ignoring the error is ok. No one could handle this error correctly.
> At this time the guest virtio driver of this virtqueue may be in an
> incorrect state.
Not sure to understand how it can happen.
But I see that last_io is actually vq->inflight_split->last_inflight_io,
which is set only by rte_vhost_set_last_inflight_io_split() API.
Shouldn't there be a sanity check there to ensure that last_inflight_io
is smaller than desc_num value set by the frontend?
Returning an error is the right thing to do anyway.
>>
>>> + } else {
>>> + inflight_split->desc[last_io].inflight = 0;
>>> + rte_atomic_thread_fence(__ATOMIC_SEQ_CST);
>>> + }
>>> inflight_split->used_idx = used->idx;
>>> }
>>>
>>>
>>
>> Regards,
>> Maxime
>>
>
next prev parent reply other threads:[~2021-10-14 11:38 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-27 5:12 Li Feng
2021-09-01 5:01 ` Li Feng
2021-10-14 8:17 ` Maxime Coquelin
2021-10-14 8:25 ` Maxime Coquelin
2021-10-14 8:28 ` Xia, Chenbo
2021-10-18 1:01 ` Liu, Changpeng
2021-10-14 11:25 ` Li Feng
2021-10-14 11:38 ` Maxime Coquelin [this message]
2021-10-14 11:54 ` Li Feng
2021-10-14 12:40 ` [dpdk-dev] [PATCH v2] vhost: add sanity check when operating the " Li Feng
2021-10-15 8:51 ` Maxime Coquelin
2021-10-15 9:25 ` Li Feng
2021-10-21 12:32 ` Maxime Coquelin
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