[PATCH 0/3] Xen: grant table related adjustments following recent XSAs

[Jan Beulich]

While addressing the XSAs a number of further oddities were noticed.
Try to take care of them.

1: gntdev: don't needlessly allocate k{,un}map_ops[]
2: gnttab: introduce common INVALID_GRANT_{HANDLE,REF}
3: gntdev: don't needlessly use kvcalloc()

Jan