[PATCH v6 0/7] Xen transport for 9pfs frontend driver

[Stefano Stabellini]

Hi all,

This patch series implements a new transport for 9pfs, aimed at Xen
systems.

The transport is based on a traditional Xen frontend and backend drivers
pair. This patch series implements the frontend, which typically runs in
a regular unprivileged guest.

I also sent a series that implements the backend in userspace in QEMU,
which typically runs in Dom0 (but could also run in a another guest).

The frontend complies to the Xen transport for 9pfs specification
version 1, available here:

https://xenbits.xen.org/docs/unstable/misc/9pfs.html


Changes in v6:
- add reviewd-bys
- fix error paths
- make p9_xen_write_todo return bool

Changes in v5:
- test priv->tag instead of ret
- run checkpatch.pl against the whole series, fix all issues
- set intf->ring_order appropriately
- use shorter link to 9pfs spec

Changes in v4:
- code style improvements
- use xenbus_read_unsigned when possible
- do not leak "versions"
- introduce BUILD_BUG_ON
- introduce rwlock to protect the xen_9pfs_devs list
- add review-by

Changes in v3:
- add full copyright header to trans_xen.c
- rename ring->ring to ring->data
- handle gnttab_grant_foreign_access errors
- remove ring->bytes
- wrap long lines
- add reviewed-by

Changes in v2:
- use XEN_PAGE_SHIFT instead of PAGE_SHIFT
- remove unnecessary initializations
- fix error paths
- fix memory allocations for 64K kernels
- simplify p9_xen_create and p9_xen_close
- use virt_XXX barriers
- set status = REQ_STATUS_ERROR inside the p9_xen_response loop
- add in-code comments


Stefano Stabellini (7):
      xen: import new ring macros in ring.h
      xen: introduce the header file for the Xen 9pfs transport protocol
      xen/9pfs: introduce Xen 9pfs transport driver
      xen/9pfs: connect to the backend
      xen/9pfs: send requests to the backend
      xen/9pfs: receive responses
      xen/9pfs: build 9pfs Xen transport driver

 include/xen/interface/io/9pfs.h |  42 ++++
 include/xen/interface/io/ring.h | 133 ++++++++++
 net/9p/Kconfig                  |   8 +
 net/9p/Makefile                 |   4 +
 net/9p/trans_xen.c              | 539 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 726 insertions(+)
 create mode 100644 include/xen/interface/io/9pfs.h
 create mode 100644 net/9p/trans_xen.c


Cheers,

Stefano