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, 14 insertions, 0 deletions

diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
index e00ddd7..e28ed48 100644
--- a/include/hw/xen/xen_common.h
+++ b/include/hw/xen/xen_common.h
@@ -78,6 +78,20 @@ static inline void *xenforeignmemory_map(xc_interface *h, uint32_t dom,
 
 extern xenforeignmemory_handle *xen_fmem;
 
+#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 41000
+
+static inline void *xenforeignmemory_map2(xenforeignmemory_handle *h,
+                                          uint32_t dom, void *addr,
+                                          int prot, int flags, size_t pages,
+                                          const xen_pfn_t arr[/*pages*/],
+                                          int err[/*pages*/])
+{
+    assert(addr == NULL && flags == 0);
+    return xenforeignmemory_map(h, dom, prot, pages, arr, err);
+}
+
+#endif
+
 #if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40900
 
 typedef xc_interface xendevicemodel_handle;