[PATCH v4 14/17] xen: Add xen_mr_is_memory()

["Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxx>]

From: "Edgar E. Iglesias" <edgar.iglesias@xxxxxxx>

Add xen_mr_is_memory() to abstract away tests for the
xen_memory MR.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xxxxxxx>
---
 hw/xen/xen-hvm-common.c | 8 +++++++-
 include/sysemu/xen.h    | 8 ++++++++
 system/physmem.c        | 2 +-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c
index 1627da7398..0267b88d26 100644
--- a/hw/xen/xen-hvm-common.c
+++ b/hw/xen/xen-hvm-common.c
@@ -12,6 +12,12 @@
 
 MemoryRegion xen_memory;
 
+/* Check for xen memory.  */
+bool xen_mr_is_memory(MemoryRegion *mr)
+{
+    return mr == &xen_memory;
+}
+
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
                    Error **errp)
 {
@@ -28,7 +34,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, 
MemoryRegion *mr,
         return;
     }
 
-    if (mr == &xen_memory) {
+    if (xen_mr_is_memory(mr)) {
         return;
     }
 
diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
index 754ec2e6cb..dc72f83bcb 100644
--- a/include/sysemu/xen.h
+++ b/include/sysemu/xen.h
@@ -34,6 +34,8 @@ void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t 
length);
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
                    struct MemoryRegion *mr, Error **errp);
 
+bool xen_mr_is_memory(MemoryRegion *mr);
+
 #else /* !CONFIG_XEN_IS_POSSIBLE */
 
 #define xen_enabled() 0
@@ -47,6 +49,12 @@ static inline void xen_ram_alloc(ram_addr_t ram_addr, 
ram_addr_t size,
     g_assert_not_reached();
 }
 
+static inline bool xen_mr_is_memory(MemoryRegion *mr)
+{
+    g_assert_not_reached();
+    return false;
+}
+
 #endif /* CONFIG_XEN_IS_POSSIBLE */
 
 #endif
diff --git a/system/physmem.c b/system/physmem.c
index ad7a8c7d95..1a5ffcba2a 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -2227,7 +2227,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, 
ram_addr_t addr,
          * because we don't want to map the entire memory in QEMU.
          * In that case just map the requested area.
          */
-        if (block->offset == 0) {
+        if (xen_mr_is_memory(block->mr)) {
             return xen_map_cache(block->mr, addr, len, lock, lock,
                                  is_write);
         }
-- 
2.40.1