Re: [PATCH v7 resend 0/4] add generic vDPA device support

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Nov 05, 2022 at 04:36:25PM +0800, Longpeng(Mike) wrote:
> From: Longpeng <longpeng2@huawei.com>
> 
> Hi guys,
> 
> With the generic vDPA device, QEMU won't need to touch the device
> types any more, such like vfio.

With this kind of passthrough migration is completely MIA right?
Better add a blocker...
And given this is there an advantage over VFIO?

> We can use the generic vDPA device as follow:
>   -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-X
>   Or
>   -M microvm -m 512m -smp 2 -kernel ... -initrd ... -device \
>   vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-x

> Changes v6 -> v7:
>     (v6: https://mail.gnu.org/archive/html/qemu-devel/2022-05/msg02821.html)
>     - rebase. [Jason]
>     - add documentation . [Stefan]
> 
> Changes v5 -> v6:
>   Patch 2:
>     - Turn to the original approach in the RFC to initialize the
>       virtio_pci_id_info array. [Michael]
> 	  https://lore.kernel.org/all/20220105005900.860-2-longpeng2@huawei.com/
>   Patch 3:
>     - Fix logical error of exception handler around the post_init.
>       [Stefano]
>     - Fix some coding style warnings. [Stefano]
>   Patch 4:
>     - Fix some coding style warnings. [Stefano]
> 
> Changes v4 -> v5:
>   Patch 3:
>     - remove vhostfd [Jason]
>     - support virtio-mmio [Jason]
> 
> Changes v3 -> v4:
>   v3: https://www.mail-archive.com/qemu-devel@nongnu.org/msg877015.html
>   - reorganize the series [Stefano]
>   - fix some typos [Stefano]
>   - fix logical error in vhost_vdpa_device_realize [Stefano]
> 
> Changes v2 -> v3
>   Patch 4 & 5:
>     - only call vdpa ioctls in vdpa-dev.c [Stefano, Longpeng]
>     - s/VQS_NUM/VQS_COUNT  [Stefano]
>     - check both vdpa_dev_fd and vdpa_dev [Stefano]
>   Patch 6:
>     - move all steps into vhost_vdpa_device_unrealize. [Stefano]
> 
> Changes RFC -> v2
>   Patch 1:
>     - rename 'pdev_id' to 'trans_devid'  [Michael]
>     - only use transitional device id for the devices
>       listed in the spec  [Michael]
>     - use macros to make the id_info table clearer  [Longpeng]
>     - add some modern devices in the id_info table  [Longpeng]
>   Patch 2:
>     - remove the GET_VECTORS_NUM command  [Jason]
>   Patch 4:
>     - expose vdpa_dev_fd as a QOM preperty  [Stefan]
>     - introduce vhost_vdpa_device_get_u32 as a common
>       function to make the code clearer  [Stefan]
>     - fix the misleading description of 'dc->desc'  [Stefano]
>   Patch 5:
>     - check returned number of virtqueues  [Stefan]
>   Patch 6:
>     - init s->num_queues  [Stefano]
>     - free s->dev.vqs  [Stefano]
> 
> 
> Longpeng (Mike) (4):
>   virtio: get class_id and pci device id by the virtio id
>   vdpa: add vdpa-dev support
>   vdpa: add vdpa-dev-pci support
>   docs: Add generic vhost-vdpa device documentation
> 
>  docs/system/devices/vhost-vdpa-device.rst |  43 +++
>  hw/virtio/Kconfig                         |   5 +
>  hw/virtio/meson.build                     |   2 +
>  hw/virtio/vdpa-dev-pci.c                  | 102 ++++++
>  hw/virtio/vdpa-dev.c                      | 377 ++++++++++++++++++++++
>  hw/virtio/virtio-pci.c                    |  88 +++++
>  include/hw/virtio/vdpa-dev.h              |  43 +++
>  include/hw/virtio/virtio-pci.h            |   5 +
>  8 files changed, 665 insertions(+)
>  create mode 100644 docs/system/devices/vhost-vdpa-device.rst
>  create mode 100644 hw/virtio/vdpa-dev-pci.c
>  create mode 100644 hw/virtio/vdpa-dev.c
>  create mode 100644 include/hw/virtio/vdpa-dev.h
> 
> -- 
> 2.23.0