Re: [PATCH V2 RESEND 2/6] vDPA: only report driver features if FEATURES_OK is set
From: Jason Wang <jasowang@redhat.com>
Date: 2022-09-27 04:37:51
Also in:
kvm, virtualization
On Tue, Sep 27, 2022 at 11:09 AM Zhu Lingshan [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This commit reports driver features to user space only after FEATURES_OK is features negotiation is done. Signed-off-by: Zhu Lingshan <redacted> --- drivers/vdpa/vdpa.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-)diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index 2035700d6fc8..e7765953307f 100644 --- a/drivers/vdpa/vdpa.c +++ b/drivers/vdpa/vdpa.c@@ -816,7 +816,7 @@ static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev, static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg) { struct virtio_net_config config = {}; - u64 features_device, features_driver; + u64 features_device; u16 val_u16; vdev->config->get_config(vdev, 0, &config, sizeof(config));@@ -833,11 +833,6 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16)) return -EMSGSIZE; - features_driver = vdev->config->get_driver_features(vdev); - if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver, - VDPA_ATTR_PAD)) - return -EMSGSIZE; - features_device = vdev->config->get_device_features(vdev); if (nla_put_u64_64bit(msg, VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, features_device,@@ -851,6 +846,8 @@ static int vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq, int flags, struct netlink_ext_ack *extack) { + u64 features_driver; + u8 status = 0; u32 device_id; void *hdr; int err;@@ -874,6 +871,19 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, goto msg_err; } + /* only read driver features after the feature negotiation is done */ + if (vdev->config->get_status) + status = vdev->config->get_status(vdev);
get_status is mandatory, so I think we can remove this check. Or if you want a strict check on the config operations, we need to do that in __vdpa_alloc_device(). Thanks
+
+ if (status & VIRTIO_CONFIG_S_FEATURES_OK) {
+ features_driver = vdev->config->get_driver_features(vdev);
+ if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver,
+ VDPA_ATTR_PAD)) {
+ err = -EMSGSIZE;
+ goto msg_err;
+ }
+ }
+
switch (device_id) {
case VIRTIO_ID_NET:
err = vdpa_dev_net_config_fill(vdev, msg);
--
2.31.1