xen/9pfs: send requests to the backend

Implement struct p9_trans_module create and close functions by looking
at the available Xen 9pfs frontend-backend connections. We don't expect
many frontend-backend connections, thus walking a list is OK.

Send requests to the backend by copying each request to one of the
available rings (each frontend-backend connection comes with multiple
rings). Handle the ring and notifications following the 9pfs
specification. If there are not enough free bytes on the ring for the
request, wait on the wait_queue: the backend will send a notification
after consuming more requests.

CC: [email protected]
CC: [email protected]
CC: Eric Van Hensbergen <[email protected]>
CC: Ron Minnich <[email protected]>
CC: Latchesar Ionkov <[email protected]>
CC: [email protected]

Signed-off-by: Stefano Stabellini <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Reviewed-by: Juergen Gross <[email protected]>
Signed-off-by: Juergen Gross <[email protected]>

0 files changed, 0 insertions, 0 deletions