Instead of returning a reference to a grant that is already present in an
array, defer the initialization. This is how the OSv driver handles it, and I
honestly am not sure if this is really needed: it seems to me we should be able
to just reuse the old grants. I need to check in the backend code if we can be
any smarter than this.
However, right now we need to do something to recycle the buffers, and just
re-doing the refs would lead to inconsistencies. So the best by now is to close
and reopen the grants, and then later on rework this in a way that works for
both the initial setup and the recycle.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
Enhance gntref with some useful operations. Also provide a default object that
represents an invalid grant.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
We used gnttab_grant_foreign_access() instead of
gnttab_grant_foreign_access_ref(). While the two functions have similar
enough signatures, they do very different things.
With the change, we are able to receive packets from Xen, though we crash
immediately.
We used gnttab_grant_foreign_access() instead of
gnttab_grant_foreign_access_ref(). While the two functions have similar
enough signatures, they do very different things.
With the change, we are able to transmit packets through Xen.
This patch creates a seastar enabled version of the xen gntalloc device.
TODO: grow the table dynamically, and fix the index selection algorithm. Shouldn't
just always bump 1.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
