From fec618a3fdcc88fa50089edb5748a6554ac49070 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Wed, 13 Dec 2017 09:51:06 +0100 Subject: [PATCH 1/6] 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 (cherry picked from commit 07f8db29b8833378dd506f3e197319f8b669aed9) Signed-off-by: Maxime Coquelin --- dpdk-17.11/lib/librte_vhost/vhost_user.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/dpdk-17.11/lib/librte_vhost/vhost_user.c b/dpdk-17.11/lib/librte_vhost/vhost_user.c index f4c7ce462..545dbcb2b 100644 --- a/dpdk-17.11/lib/librte_vhost/vhost_user.c +++ b/dpdk-17.11/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->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); } -- 2.14.3