diff options
| author | Eli Cohen <elic@nvidia.com> | 2022-01-05 13:46:36 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2022-01-14 18:50:53 -0500 |
| commit | 30ef7a8ac8a07046b9ac9206d3a732a9f76b2e60 (patch) | |
| tree | d352b3baea263b80673b06e56344aac1c6d9dfda /drivers/vdpa/vdpa.c | |
| parent | 73bc0dbb591baea322a7319c735e5f6c7dba9cfb (diff) | |
vdpa: Read device configuration only if FEATURES_OK
Avoid reading device configuration during feature negotiation. Read
device status and verify that VIRTIO_CONFIG_S_FEATURES_OK is set.
Protect the entire operation, including configuration read with cf_mutex
to ensure integrity of the results.
Signed-off-by: Eli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-5-elic@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Diffstat (limited to 'drivers/vdpa/vdpa.c')
| -rw-r--r-- | drivers/vdpa/vdpa.c | 45 |
1 files changed, 33 insertions, 12 deletions
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index 5134c83c4a22..4494325cae91 100644 --- a/drivers/vdpa/vdpa.c +++ b/drivers/vdpa/vdpa.c @@ -393,6 +393,21 @@ void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev) } EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister); +static void vdpa_get_config_unlocked(struct vdpa_device *vdev, + unsigned int offset, + void *buf, unsigned int len) +{ + const struct vdpa_config_ops *ops = vdev->config; + + /* + * Config accesses aren't supposed to trigger before features are set. + * If it does happen we assume a legacy guest. + */ + if (!vdev->features_valid) + vdpa_set_features(vdev, 0); + ops->get_config(vdev, offset, buf, len); +} + /** * vdpa_get_config - Get one or more device configuration fields. * @vdev: vdpa device to operate on @@ -403,16 +418,8 @@ EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister); void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, void *buf, unsigned int len) { - const struct vdpa_config_ops *ops = vdev->config; - mutex_lock(&vdev->cf_mutex); - /* - * Config accesses aren't supposed to trigger before features are set. - * If it does happen we assume a legacy guest. - */ - if (!vdev->features_valid) - vdpa_set_features(vdev, 0); - ops->get_config(vdev, offset, buf, len); + vdpa_get_config_unlocked(vdev, offset, buf, len); mutex_unlock(&vdev->cf_mutex); } EXPORT_SYMBOL_GPL(vdpa_get_config); @@ -813,7 +820,7 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms u64 features; u16 val_u16; - vdpa_get_config(vdev, 0, &config, sizeof(config)); + vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config)); if (nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR, sizeof(config.mac), config.mac)) @@ -838,12 +845,23 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, { u32 device_id; void *hdr; + u8 status; int err; + mutex_lock(&vdev->cf_mutex); + status = vdev->config->get_status(vdev); + if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) { + NL_SET_ERR_MSG_MOD(extack, "Features negotiation not completed"); + err = -EAGAIN; + goto out; + } + hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_DEV_CONFIG_GET); - if (!hdr) - return -EMSGSIZE; + if (!hdr) { + err = -EMSGSIZE; + goto out; + } if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) { err = -EMSGSIZE; @@ -867,11 +885,14 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, if (err) goto msg_err; + mutex_unlock(&vdev->cf_mutex); genlmsg_end(msg, hdr); return 0; msg_err: genlmsg_cancel(msg, hdr); +out: + mutex_unlock(&vdev->cf_mutex); return err; } |