On 10/24/2022 1:40 AM, Jason Wang wrote:
On Sat, Oct 22, 2022 at 7:49 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 as-is,
the way how vdpa device was created. The "vdpa dev show" command
seems to be the right vehicle for that. It is unlike the "vdpa dev
config show" command output which usually goes with the live value
in the device config space, and is not quite reliable subject to
the dynamics of feature negotiation or possible change by the
driver to the 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
initial_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,
"initial_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 bebded6..bfb8f54 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_initcfg_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 device_id)
+{
+ struct vdpa_dev_set_config *cfg = &vdev->init_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;
+ 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;
A question: If any of those above attributes were not provisioned,
should we show the ones that are inherited from the parent?
A simple answer would be yes, but the long answer is that I am not sure
if there's any for the moment - there's no default value for mtu, mac,
and max_vqp that can be inherited from the parent (max_vqp by default
being 1 is spec defined, not something inherited from the parent). And
the device_features if inherited is displayed at 'vdpa dev config show'
output. Can you remind me of a good example for inherited value that we
may want to show here?
Thanks,
-Siwei
Thanks
+
+ 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_initcfg_fill(vdev, msg, device_id);
+ if (err)
+ goto msg_err;
+
genlmsg_end(msg, hdr);
return 0;
--
1.8.3.1
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