On 10/19/2022 10:25 PM, Jason Wang wrote:
On Wed, Oct 19, 2022 at 8:56 AM Si-Wei Liu <si-wei.liu@xxxxxxxxxx> wrote:
Live migration of vdpa would typically require re-instate vdpa
device with an idential set of configs on the destination node,
same way as how source node created the device in the first
place. In order to save orchestration software from memorizing
and keeping track of vdpa config, it will be helpful if the vdpa
tool provides the aids for exporting the initial configs from
which vdpa device was created as-is. The "vdpa dev show" command
seems to be the right vehicle for that. It is unlike the "vdpa dev
config show" command output that usually goes with the live value
in the device config space, which is not quite reliable subject to
the dynamics of feature negotiation and possible change in device
config space.
Examples:
1) Create vDPA by default without any config attribute
$ vdpa dev add mgmtdev pci/0000:41:04.2 name vdpa0
$ vdpa dev show vdpa0
vdpa0: type network mgmtdev pci/0000:41:04.2 vendor_id 5555 max_vqs 9 max_vq_size 256
$ vdpa dev -jp show vdpa0
{
"dev": {
"vdpa0": {
"type": "network",
"mgmtdev": "pci/0000:41:04.2",
"vendor_id": 5555,
"max_vqs": 9,
"max_vq_size": 256,
}
}
}
2) Create vDPA with config attribute(s) specified
$ vdpa dev add mgmtdev pci/0000:41:04.2 name vdpa0 \
mac e4:11:c6:d3:45:f0 max_vq_pairs 4
$ vdpa dev show
vdpa0: type network mgmtdev pci/0000:41:04.2 vendor_id 5555 max_vqs 9 max_vq_size 256
virtio_config: mac e4:11:c6:d3:45:f0 max_vq_pairs 4
$ vdpa dev -jp show
{
"dev": {
"vdpa0": {
"type": "network",
"mgmtdev": "pci/0000:41:04.2",
"vendor_id": 5555,
"max_vqs": 9,
"max_vq_size": 256,
"virtio_config": {
"mac": "e4:11:c6:d3:45:f0",
"max_vq_pairs": 4
}
}
}
}
Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
---
drivers/vdpa/vdpa.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 566c1c6..91eca6d 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -677,6 +677,41 @@ static int vdpa_nl_cmd_dev_del_set_doit(struct sk_buff *skb, struct genl_info *i
}
static int
+vdpa_dev_cfgattrs_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 device_id)
+{
+ struct vdpa_dev_set_config *cfg = &vdev->vdev_cfg;
+ int err = -EMSGSIZE;
+
+ if (!cfg->mask)
+ return 0;
+
+ switch (device_id) {
+ case VIRTIO_ID_NET:
+ if ((cfg->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR)) != 0 &&
+ nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR,
+ sizeof(cfg->net.mac), cfg->net.mac))
+ return err;
+ if ((cfg->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)) != 0 &&
+ nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, cfg->net.mtu))
+ return err;
+ if ((cfg->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) != 0 &&
+ nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP,
+ cfg->net.max_vq_pairs))
+ return err;
+ break;
This makes me think if we can reuse the virtio_net_config structure
other than duplicate it slowly with a dedicated nested structure
inside vdpa_dev_set_config then we can reuse the
vdpa_dev_net_config_fill().
Adding Parav.
I think for now the struct vdpa_dev_set_config has just a few fields, so
it's not very obvious. But from what I understand, the
vdpa_dev_set_config struct is designed to be built around vdpa
configurables, without getting it limited by what's exposed by the
virtio device config structure, such as virtio_net_config. For instance,
there could be possibility for vdpa user to specify the size of MAC
unicast or multicast address table, which is not defined anywhere in the
virtio_net_config. I think it's important to match such configuration
(which may not even be defined in spec) for src&dst vdpa devices
involving the live migration.
-Siwei
Thanks
+ default:
+ break;
+ }
+
+ if ((cfg->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES)) != 0 &&
+ nla_put_u64_64bit(msg, VDPA_ATTR_DEV_FEATURES,
+ cfg->device_features, VDPA_ATTR_PAD))
+ return err;
+
+ return 0;
+}
+
+static int
vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
int flags, struct netlink_ext_ack *extack)
{
@@ -715,6 +750,10 @@ static int vdpa_nl_cmd_dev_del_set_doit(struct sk_buff *skb, struct genl_info *i
if (nla_put_u16(msg, VDPA_ATTR_DEV_MIN_VQ_SIZE, min_vq_size))
goto msg_err;
+ err = vdpa_dev_cfgattrs_fill(vdev, msg, device_id);
+ if (err)
+ goto msg_err;
+
genlmsg_end(msg, hdr);
return 0;
--
1.8.3.1
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