xen/mapcache: introduce xen_replace_cache_entry()

This new call is trying to update a requested map cache entry
according to the changes in the physmap. The call is searching
for the entry, unmaps it and maps again at the same place using
a new guest address. If the mapping is dummy this call will
make it real.

This function makes use of a new xenforeignmemory_map2() call
with an extended interface that was recently introduced in
libxenforeignmemory [1].

[1] https://www.mail-archive.com/xen-devel@lists.xen.org/msg113007.html

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>

1 files changed, 10 insertions, 1 deletions

diff --git a/include/sysemu/xen-mapcache.h b/include/sysemu/xen-mapcache.h
index 01daaad00c..bd4d49e0a4 100644
--- a/include/sysemu/xen-mapcache.h
+++ b/include/sysemu/xen-mapcache.h
@@ -21,7 +21,9 @@ uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,
 ram_addr_t xen_ram_addr_from_mapcache(void *ptr);
 void xen_invalidate_map_cache_entry(uint8_t *buffer);
 void xen_invalidate_map_cache(void);
-
+uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr,
+                                 hwaddr new_phys_addr,
+                                 hwaddr size);
 #else
 
 static inline void xen_map_cache_init(phys_offset_to_gaddr_t f,
@@ -50,6 +52,13 @@ static inline void xen_invalidate_map_cache(void)
 {
 }
 
+static inline uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr,
+                                               hwaddr new_phys_addr,
+                                               hwaddr size)
+{
+    abort();
+}
+
 #endif
 
 #endif /* XEN_MAPCACHE_H */