memory: expose alignment used for allocating RAM as MemoryRegion API

introduce memory_region_get_alignment() that returns
underlying memory block alignment or 0 if it's not
relevant/implemented for backend.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 8c9d80e9fe..16fcec2f37 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -124,7 +124,7 @@ void *qemu_memalign(size_t alignment, size_t size)
 }
 
 /* alloc shared memory pages */
-void *qemu_anon_ram_alloc(size_t size)
+void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
 {
     size_t align = QEMU_VMALLOC_ALIGN;
     size_t total = size + align - getpagesize();
@@ -136,6 +136,9 @@ void *qemu_anon_ram_alloc(size_t size)
         return NULL;
     }
 
+    if (alignment) {
+        *alignment = align;
+    }
     ptr += offset;
     total -= offset;