[PATCH 1/2] vDPA: allow userspace to query features of a vDPA device

Zhu Lingshan
2022-08-15T09:34:56Z

This commit adds a new vDPA netlink attribution
VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES. Userspace can query
features of vDPA devices through this new attr.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
drivers/vdpa/vdpa.c | 17 +++++++++++++----
include/uapi/linux/vdpa.h | 3 +++
2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index c06c02704461..efb55a06e961 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -491,6 +491,8 @@ static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *m
err = -EMSGSIZE;
goto msg_err;
}
+
+ /* report features of a vDPA management device through VDPA_ATTR_DEV_SUPPORTED_FEATURES */
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES,
mdev->supported_features, VDPA_ATTR_PAD)) {
err = -EMSGSIZE;
@@ -815,7 +817,7 @@ 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;
+ u64 features_device, features_driver;
u16 val_u16;

vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config));
@@ -832,12 +834,19 @@ 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 = vdev->config->get_driver_features(vdev);
- if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features,
+ 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);
+
+ /* report features of a vDPA device through VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES */
+ if (nla_put_u64_64bit(msg, VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, features_device,
VDPA_ATTR_PAD))
return -EMSGSIZE;

- return vdpa_dev_net_mq_config_fill(vdev, msg, features, &config);
+ return vdpa_dev_net_mq_config_fill(vdev, msg, features_driver, &config);
}

static int
diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 25c55cab3d7c..d171b92ef522 100644
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -46,7 +46,10 @@ enum vdpa_attr {

VDPA_ATTR_DEV_NEGOTIATED_FEATURES, /* u64 */
VDPA_ATTR_DEV_MGMTDEV_MAX_VQS, /* u32 */
+ /* features of a vDPA management device */
VDPA_ATTR_DEV_SUPPORTED_FEATURES, /* u64 */
+ /* features of a vDPA device, e.g., /dev/vhost-vdpa0 */
+ VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, /* u64 */

VDPA_ATTR_DEV_QUEUE_INDEX, /* u32 */
VDPA_ATTR_DEV_VENDOR_ATTR_NAME, /* string */
--
2.31.1