From: Ladi Prosek <lprosek@redhat.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev@dpdk.org, yliu@fridaylinux.org, tiwei.bie@intel.com,
jianfeng.tan@intel.com, Laszlo Ersek <lersek@redhat.com>
Subject: Re: [dpdk-dev] [PATCH 1/4] vhost: prevent features to be changed while device is running
Date: Mon, 4 Dec 2017 15:17:43 +0100 [thread overview]
Message-ID: <CABdb736=5pK0QsJB7P3d7bMmT5wG0TL-APufmz21Lpp=YVijcQ@mail.gmail.com> (raw)
In-Reply-To: <20171204140900.7906-2-maxime.coquelin@redhat.com>
On Mon, Dec 4, 2017 at 3:08 PM, Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
> As section 2.2 of the Virtio spec states about features
> negotiation:
> "During device initialization, the driver reads this and tells
> the device the subset that it accepts. The only way to
> renegotiate is to reset the device."
>
> This patch implements a check to prevent illegal features change
> while the device is running.
>
> One exception is the VHOST_F_LOG_ALL feature bit, which is enabled
> when live-migration is initiated. But this feature is not negotiated
> with the Virtio driver, but directly with the Vhost master.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
> lib/librte_vhost/vhost_user.c | 17 ++++++++++++++++-
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index f4c7ce462..f51055ab2 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -183,7 +183,22 @@ vhost_user_set_features(struct virtio_net *dev, uint64_t features)
> return -1;
> }
>
> - if ((dev->flags & VIRTIO_DEV_RUNNING) && dev->features != features) {
> + if (dev->features == features)
> + return 0;
> +
> + if (dev->flags & VIRTIO_DEV_RUNNING) {
> + /*
> + * Error out if master tries to change features while device is
> + * in running state. The exception being VHOST_F_LOG_ALL, which
> + * is enabled when the live-migration starts.
> + */
> + if ((dev->features ^ features) & ~(1ULL >> VHOST_F_LOG_ALL)) {
The 1 should be shifted to the left:
1ULL << VHOST_F_LOG_ALL
> + RTE_LOG(ERR, VHOST_CONFIG,
> + "(%d) features changed while device is running.\n",
> + dev->vid);
> + return -1;
> + }
> +
> if (dev->notify_ops->features_changed)
> dev->notify_ops->features_changed(dev->vid, features);
> }
> --
> 2.14.3
>
next prev parent reply other threads:[~2017-12-04 14:17 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-04 14:08 [dpdk-dev] [PATCH 0/4] Vhost: fix mq=on but VIRTIO_NET_F_MQ not negotiated Maxime Coquelin
2017-12-04 14:08 ` [dpdk-dev] [PATCH 1/4] vhost: prevent features to be changed while device is running Maxime Coquelin
2017-12-04 14:17 ` Ladi Prosek [this message]
2017-12-04 14:20 ` Maxime Coquelin
2017-12-04 14:08 ` [dpdk-dev] [PATCH 2/4] vhost: propagate VHOST_USER_SET_FEATURES handling error Maxime Coquelin
2017-12-04 14:08 ` [dpdk-dev] [PATCH 3/4] vhost: extract virtqueue cleaning and freeing functions Maxime Coquelin
2017-12-04 14:09 ` [dpdk-dev] [PATCH 4/4] vhost: destroy unused virtqueues when multiqueue not negotiated Maxime Coquelin
2017-12-04 14:27 ` [dpdk-dev] [PATCH 0/4] Vhost: fix mq=on but VIRTIO_NET_F_MQ " Ladi Prosek
2017-12-04 14:48 ` Maxime Coquelin
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