xen: implement updated XENMEM_add_to_physmap_range ABI

Allows for more fine grained error reporting. Only used by PVH and
ARM both of which are marked EXPERIMENTAL precisely because the ABI
is not yet stable

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[v1: Rebased without PVH patches]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

2 files changed, 11 insertions, 3 deletions

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 7a32976fa2a3..8dc0605a9ce9 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -59,14 +59,16 @@ static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
         };
         xen_ulong_t idx = fgmfn;
         xen_pfn_t gpfn = lpfn;
+        int err = 0;
 
         set_xen_guest_handle(xatp.idxs, &idx);
         set_xen_guest_handle(xatp.gpfns, &gpfn);
+        set_xen_guest_handle(xatp.errs, &err);
 
         rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
-        if (rc) {
-                pr_warn("Failed to map pfn to mfn rc:%d pfn:%lx mfn:%lx\n",
-                        rc, lpfn, fgmfn);
+        if (rc || err) {
+                pr_warn("Failed to map pfn to mfn rc:%d:%d pfn:%lx mfn:%lx\n",
+                        rc, err, lpfn, fgmfn);
                 return 1;
         }
         return 0;
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index b40a4315cb8b..2ecfe4f700d9 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -190,6 +190,7 @@ DEFINE_GUEST_HANDLE_STRUCT(xen_add_to_physmap);
 
 #define XENMEM_add_to_physmap_range 23
 struct xen_add_to_physmap_range {
+    /* IN */
     /* Which domain to change the mapping for. */
     domid_t domid;
     uint16_t space; /* => enum phys_map_space */
@@ -203,6 +204,11 @@ struct xen_add_to_physmap_range {
 
     /* GPFN in domid where the source mapping page should appear. */
     GUEST_HANDLE(xen_pfn_t) gpfns;
+
+    /* OUT */
+
+    /* Per index error code. */
+    GUEST_HANDLE(int) errs;
 };
 DEFINE_GUEST_HANDLE_STRUCT(xen_add_to_physmap_range);