xenbus_client: Extend interface to support multi-page ring

Originally Xen PV drivers only use single-page ring to pass along
information. This might limit the throughput between frontend and
backend.

The patch extends Xenbus driver to support multi-page ring, which in
general should improve throughput if ring is the bottleneck. Changes to
various frontend / backend to adapt to the new interface are also
included.

Affected Xen drivers:
* blkfront/back
* netfront/back
* pcifront/back
* scsifront/back
* vtpmfront

The interface is documented, as before, in xenbus_client.c.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This commit is contained in:
Wei Liu 2015-04-03 14:44:59 +08:00 committed by David Vrabel
commit ccc9d90a9a
11 changed files with 325 additions and 126 deletions

View file

@ -46,6 +46,10 @@
#include <xen/interface/io/xenbus.h>
#include <xen/interface/io/xs_wire.h>
#define XENBUS_MAX_RING_PAGE_ORDER 4
#define XENBUS_MAX_RING_PAGES (1U << XENBUS_MAX_RING_PAGE_ORDER)
#define INVALID_GRANT_HANDLE (~0U)
/* Register callback to watch this node. */
struct xenbus_watch
{
@ -199,15 +203,19 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
const char *pathfmt, ...);
int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
int xenbus_map_ring_valloc(struct xenbus_device *dev,
int gnt_ref, void **vaddr);
int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
grant_handle_t *handle, void *vaddr);
int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
unsigned int nr_pages, grant_ref_t *grefs);
int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
unsigned int nr_grefs, void **vaddr);
int xenbus_map_ring(struct xenbus_device *dev,
grant_ref_t *gnt_refs, unsigned int nr_grefs,
grant_handle_t *handles, unsigned long *vaddrs,
bool *leaked);
int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
int xenbus_unmap_ring(struct xenbus_device *dev,
grant_handle_t handle, void *vaddr);
grant_handle_t *handles, unsigned int nr_handles,
unsigned long *vaddrs);
int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
int xenbus_free_evtchn(struct xenbus_device *dev, int port);