[PATCH V4 19/25] hostmem-memfd: cpr support

[Steve Sistare <steven.sistare@oracle.com>]

Preserve memory-backend-memfd memory objects during cpr.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 backends/hostmem-memfd.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c
index 69b0ae3..3503c89 100644
--- a/backends/hostmem-memfd.c
+++ b/backends/hostmem-memfd.c
@@ -15,6 +15,7 @@
 #include "sysemu/sysemu.h"
 #include "qom/object_interfaces.h"
 #include "qemu/memfd.h"
+#include "qemu/env.h"
 #include "qemu/module.h"
 #include "qapi/error.h"
 #include "qom/object.h"
@@ -36,23 +37,25 @@ static void
 memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
 {
     HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(backend);
-    char *name;
-    int fd;
+    char *name = host_memory_backend_get_name(backend);
+    int fd = getenv_fd(name);
 
     if (!backend->size) {
         error_setg(errp, "can't create backend with size 0");
         return;
     }
 
-    fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size,
-                           m->hugetlb, m->hugetlbsize, m->seal ?
-                           F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL : 0,
-                           errp);
-    if (fd == -1) {
-        return;
+    if (fd < 0) {
+        fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size,
+                               m->hugetlb, m->hugetlbsize, m->seal ?
+                               F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL : 0,
+                               errp);
+        if (fd == -1) {
+            return;
+        }
+        setenv_fd(name, fd);
     }
 
-    name = host_memory_backend_get_name(backend);
     memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
                                    name, backend->size,
                                    backend->share, fd, 0, errp);
-- 
1.8.3.1