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 allow live migration orchestration software to export the initial set of vdpa attributes with which the device was created, it will be useful if the vdpa tool can report the config on demand with simple query. This will ease the orchestration software implementation so that it doesn't have to keep track of vdpa config change, or have to persist vdpa attributes across failure and recovery, in fear of being killed due to accidental software error. In this series, the initial device config for vdpa creation will be exported via the "vdpa dev show" command. This is unlike the "vdpa dev config show" command that usually goes with the live value in the device config space, and is not reliable subject to the dynamics of feature negotiation or possible change by 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 } } } } --- v2 -> v3: - Rename vdev_cfg to init_cfg and also related function (Jason) - Change "virtio_config" to "initial_config" in command example output (Parav) v1 -> v2: - Revised example output to export all config attributes under a json object (Jason) --- Si-Wei Liu (4): vdpa: save vdpa_dev_set_config in struct vdpa_device vdpa: pass initial config to _vdpa_register_device() vdpa: show dev config as-is in "vdpa dev show" output vdpa: fix improper error message when adding vdpa dev drivers/vdpa/ifcvf/ifcvf_main.c | 2 +- drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +- drivers/vdpa/vdpa.c | 63 +++++++++++++++++++++++++++++++++--- drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 2 +- drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 2 +- drivers/vdpa/vdpa_user/vduse_dev.c | 2 +- drivers/vdpa/virtio_pci/vp_vdpa.c | 3 +- include/linux/vdpa.h | 26 ++++++++------- 8 files changed, 80 insertions(+), 22 deletions(-) -- 1.8.3.1 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization