From: David Marchand <david.marchand@redhat.com>
To: Chenbo Xia <chenbo.xia@intel.com>,
Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev <dev@dpdk.org>, Kevin Traynor <ktraynor@redhat.com>,
Pei Zhang <pezhang@redhat.com>,
"Yigit, Ferruh" <ferruh.yigit@intel.com>,
Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [dpdk-dev] [PATCH] vhost: fix wrong IOTLB initialization
Date: Thu, 13 May 2021 16:11:43 +0200 [thread overview]
Message-ID: <CAJFAV8wLSYgd+CtNyWjnqK3428pOrSrALXpFC9EEtj3oV3MOeg@mail.gmail.com> (raw)
In-Reply-To: <20210513122826.49910-1-chenbo.xia@intel.com>
On Thu, May 13, 2021 at 2:38 PM Chenbo Xia <chenbo.xia@intel.com> wrote:
>
> This patch fixes an issue of application crash because of vhost iotlb
> not initialized when virtio has multiqueue enabled.
>
> iotlb messages will be sent when some queues are not enabled. If we
> initialize iotlb in vhost_user_set_vring_num, it could happen that
> iotlb update comes when iotlb pool of disabled queues are not
> initialized.
This makes the problem I reproduced disappear at init, but I noticed
the segfault after restarting testpmd once.
And a little bit after this, my vm crashed.
This is not systematic, so I guess there is some condition with how
the virtio device is initialised in the vm.
One question below.
Bugzilla ID: 703
> Fixes: 968bbc7e2e50 ("vhost: avoid IOTLB mempool allocation while IOMMU disabled")
>
Reported-by: Pei Zhang <pezhang@redhat.com>
> Signed-off-by: Chenbo Xia <chenbo.xia@intel.com>
> ---
> lib/vhost/vhost_user.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 611ff209e3..ae4df8eb69 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -311,6 +311,7 @@ vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
> uint64_t features = msg->payload.u64;
> uint64_t vhost_features = 0;
> struct rte_vdpa_device *vdpa_dev;
> + uint32_t i;
>
> if (validate_msg_fds(msg, 0) != 0)
> return RTE_VHOST_MSG_RESULT_ERR;
> @@ -389,6 +390,14 @@ vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
> vdpa_dev->ops->set_features(dev->vid);
>
> dev->flags &= ~VIRTIO_DEV_FEATURES_FAILED;
> +
> + if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)) {
> + for (i = 0; i < dev->nr_vring; i++) {
I don't know the vhost-user protocol.
At this point of the device init/life, are we sure nr_vring is set to
the max number of vring?
The logs I have tend to say it is the case, but is there a guarantee
in the protocol?
Another way to fix would be to allocate on the first
VHOST_USER_IOTLB_MSG message received for a vring.
> + if (vhost_user_iotlb_init(dev, i))
> + return RTE_VHOST_MSG_RESULT_ERR;
> + }
> + }
> +
> return RTE_VHOST_MSG_RESULT_OK;
> }
>
--
David Marchand
next prev parent reply other threads:[~2021-05-13 14:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-13 12:28 Chenbo Xia
2021-05-13 13:10 ` Ferruh Yigit
2021-05-13 13:26 ` Kevin Traynor
2021-05-13 14:11 ` David Marchand [this message]
2021-05-13 14:38 ` Kevin Traynor
2021-05-13 15:03 ` Ferruh Yigit
2021-05-14 8:18 ` David Marchand
2021-05-14 9:09 ` Ferruh Yigit
2021-05-14 9:25 ` Thomas Monjalon
2021-05-14 8:16 ` David Marchand
2021-05-17 12:46 ` Xia, Chenbo
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