[PATCH v4 0/5] vduse: Add support for reconnection

[Cindy Lu]

Here is the reconnect support in vduse,

Kernel will allocate pages for reconnection.
Userspace needs to use mmap to map the memory to userspace and use these pages to
save the reconnect information.

test passd in vduse+dpdk-testpmd

change in V2
1. Address the comments from v1
2. Add the document for reconnect process

change in V3
1. Move the vdpa_vq_state to the uAPI.  vduse will use this to synchronize the vq info between the kernel and userspace app.
2. Add a new ioctl VDUSE_DEV_GET_CONFIG. userspace app use this to get config space
3. Rewrite the commit message.
4. Only save the address for the page address and remove the index.
5. remove the ioctl VDUSE_GET_RECONNECT_INFO, userspace app will use uAPI VDUSE_RECONNCT_MMAP_SIZE to mmap
6. Rewrite the document for the reconnect process to make it clearer.

change in v4
1. Change the number of map pages to VQ numbers. UserSpace APP can define and maintain the structure for saving reconnection information in userspace. The kernel will not maintain this information.
2. Rewrite the document for the reconnect process to make it clearer.
3. add the new ioctl for VDUSE_DEV_GET_CONFIG/VDUSE_DEV_GET_STATUS

Cindy Lu (5):
  vduse: Add new ioctl VDUSE_DEV_GET_CONFIG
  vduse: Add new ioctl VDUSE_DEV_GET_STATUS
  vduse: Add function to get/free the pages for reconnection
  vduse: Add file operation for mmap
  Documentation: Add reconnect process for VDUSE

 Documentation/userspace-api/vduse.rst |  32 +++++++
 drivers/vdpa/vdpa_user/vduse_dev.c    | 125 ++++++++++++++++++++++++++
 include/uapi/linux/vduse.h            |   5 ++
 3 files changed, 162 insertions(+)

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2.43.0