[Qemu-devel] [patch 2/2] qemu: add -mem-path-force option to force RAM allocation via -mem-path

[Marcelo Tosatti <mtosatti@redhat.com>]

[-- Attachment #1: add-option-to-force-mem-path --]
[-- Type: text/plain, Size: 3108 bytes --]

Default behaviour is to fallback for standard RAM allocation if -mem-path
allocation fails.

Add an option to force -mem-path RAM allocation (failing otherwise).

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: qemu/exec.c
===================================================================
--- qemu.orig/exec.c
+++ qemu/exec.c
@@ -985,6 +985,9 @@ static void *file_ram_alloc(RAMBlock *bl
     if (area == MAP_FAILED) {
         perror("file_ram_alloc: can't mmap RAM pages");
         close(fd);
+        if (mem_path_force) {
+            exit(1);
+        }
         return (NULL);
     }
 
Index: qemu/vl.c
===================================================================
--- qemu.orig/vl.c
+++ qemu/vl.c
@@ -189,6 +189,7 @@ const char* keyboard_layout = NULL;
 ram_addr_t ram_size;
 const char *mem_path = NULL;
 int mem_prealloc = 0; /* force preallocation of physical target memory */
+int mem_path_force = 0; /* quit in case -mem-path allocation fails */
 int nb_nics;
 NICInfo nd_table[MAX_NICS];
 int autostart;
@@ -3203,6 +3204,9 @@ int main(int argc, char **argv, char **e
             case QEMU_OPTION_mempath:
                 mem_path = optarg;
                 break;
+            case QEMU_OPTION_mempath_force:
+                mem_path_force = 1;
+                break;
             case QEMU_OPTION_mem_prealloc:
                 mem_prealloc = 1;
                 break;
Index: qemu/include/exec/cpu-all.h
===================================================================
--- qemu.orig/include/exec/cpu-all.h
+++ qemu/include/exec/cpu-all.h
@@ -468,6 +468,7 @@ typedef struct RAMList {
 extern RAMList ram_list;
 
 extern const char *mem_path;
+extern int mem_path_force;
 extern int mem_prealloc;
 
 /* Flags stored in the low bits of the TLB virtual address.  These are
Index: qemu/qemu-options.def
===================================================================
--- qemu.orig/qemu-options.def
+++ qemu/qemu-options.def
@@ -66,6 +66,9 @@ stringify(DEFAULT_RAM_SIZE) "]\n", QEMU_
 DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
 "-mem-path FILE  provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
 
+DEF("mem-path-force", 0, QEMU_OPTION_mempath_force,
+"-mem-path-force    fail if unable to allocate RAM as specified by -mem-path\n", QEMU_ARCH_ALL)
+
 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
 "-mem-prealloc   preallocate guest memory (use with -mem-path)\n",
 QEMU_ARCH_ALL)
Index: qemu/qemu-options.hx
===================================================================
--- qemu.orig/qemu-options.hx
+++ qemu/qemu-options.hx
@@ -228,6 +228,14 @@ STEXI
 Allocate guest RAM from a temporarily created file in @var{path}.
 ETEXI
 
+DEF("mem-path-force", 0, QEMU_OPTION_mempath_force,
+    "-mem-path-force    fail if unable to allocate RAM as specified by -mem-path\n", QEMU_ARCH_ALL)
+STEXI
+@item -mem-path-force
+@findex -mem-path-force
+Fail if unable to allocate RAM as specified by -mem-path.
+ETEXI
+
 DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
     "-mem-prealloc   preallocate guest memory (use with -mem-path)\n",
     QEMU_ARCH_ALL)