vdpa: device feature provisioning

This patch allows the device features to be provisioned through
netlink. A new attribute is introduced to allow the userspace to pass
a 64bit device features during device adding.

This provides several advantages:

- Allow to provision a subset of the features to ease the cross vendor
  live migration.
- Better debug-ability for vDPA framework and parent.

Reviewed-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220927074810.28627-2-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index c06c027..278e26b 100644 (file)
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -600,6 +600,11 @@ static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *i
                }
                config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP);
        }
+       if (nl_attrs[VDPA_ATTR_DEV_FEATURES]) {
+               config.device_features =
+                       nla_get_u64(nl_attrs[VDPA_ATTR_DEV_FEATURES]);
+               config.mask |= BIT_ULL(VDPA_ATTR_DEV_FEATURES);
+       }
 
        /* Skip checking capability if user didn't prefer to configure any
         * device networking attributes. It is likely that user might have used

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index d282f46..6d0f5e4 100644 (file)
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -104,6 +104,7 @@ struct vdpa_iova_range {
 };
 
 struct vdpa_dev_set_config {
+       u64 device_features;
        struct {
                u8 mac[ETH_ALEN];
                u16 mtu;

diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 25c55ca..9dc855f 100644 (file)
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -52,6 +52,8 @@ enum vdpa_attr {
        VDPA_ATTR_DEV_VENDOR_ATTR_NAME,         /* string */
        VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,        /* u64 */
 
+       VDPA_ATTR_DEV_FEATURES,                 /* u64 */
+
        /* new attributes must be added above here */
        VDPA_ATTR_MAX,
 };