From: Maxime Coquelin Date: Wed, 13 Dec 2017 08:51:06 +0000 (+0100) Subject: vhost: prevent features to be changed while device is running X-Git-Tag: spdx-start~515 X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=07f8db29b8833378dd506f3e197319f8b669aed9;p=dpdk.git vhost: prevent features to be changed while device is running 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 Acked-by: Laszlo Ersek Acked-by: Yuanhan Liu --- diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c index fd58ad6b4d..a3455ff3cd 100644 --- a/lib/librte_vhost/vhost_user.c +++ b/lib/librte_vhost/vhost_user.c @@ -154,7 +154,22 @@ vhost_user_set_features(struct virtio_net *dev, uint64_t features) return -1; } - if ((dev->flags & VIRTIO_DEV_RUNNING) && dev->features != features) { + if (dev->flags & VIRTIO_DEV_RUNNING) { + if (dev->features == features) + return 0; + + /* + * 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)) { + 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); }