[Qemu-devel] [PATCH v18 13/14] memory backend: fill memory backend ram fields

[Hu Tao]

Thus makes user control how to allocate memory for ram backend.

Signed-off-by: Hu Tao <address@hidden>
---
 backends/hostmem-ram.c  | 158 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/sysemu.h |   2 +
 2 files changed, 160 insertions(+)

diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c
index a496dbd..2da9341 100644
--- a/backends/hostmem-ram.c
+++ b/backends/hostmem-ram.c
@@ -10,23 +10,179 @@
  * See the COPYING file in the top-level directory.
  */
 #include "sysemu/hostmem.h"
+#include "sysemu/sysemu.h"
+#include "qemu/bitmap.h"
+#include "qapi-visit.h"
+#include "qemu/config-file.h"
+#include "qapi/opts-visitor.h"
 
 #define TYPE_MEMORY_BACKEND_RAM "memory-ram"
+#define MEMORY_BACKEND_RAM(obj) \
+    OBJECT_CHECK(HostMemoryBackendRam, (obj), TYPE_MEMORY_BACKEND_RAM)
 
+typedef struct HostMemoryBackendRam HostMemoryBackendRam;
+
+/**
+ * @HostMemoryBackendRam
+ *
+ * @parent: opaque parent object container
+ * @host_nodes: host nodes bitmap used for memory policy
+ * @policy: host memory policy
+ * @relative: if the host nodes bitmap is relative
+ */
+struct HostMemoryBackendRam {
+    /* private */
+    HostMemoryBackend parent;
+
+    DECLARE_BITMAP(host_nodes, MAX_NODES);
+    HostMemPolicy policy;
+    bool relative;
+};
+
+static void
+get_host_nodes(Object *obj, Visitor *v, void *opaque, const char *name,
+               Error **errp)
+{
+    HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(obj);
+    uint16List *host_nodes = NULL;
+    uint16List **node = &host_nodes;
+    unsigned long value;
+
+    value = find_first_bit(ram_backend->host_nodes, MAX_NODES);
+    if (value == MAX_NODES) {
+        return;
+    }
+
+    *node = g_malloc0(sizeof(**node));
+    (*node)->value = value;
+    node = &(*node)->next;
+
+    do {
+        value = find_next_bit(ram_backend->host_nodes, MAX_NODES, value + 1);
+        if (value == MAX_NODES) {
+            break;
+        }
+
+        *node = g_malloc0(sizeof(**node));
+        (*node)->value = value;
+        node = &(*node)->next;
+    } while (true);
+
+    visit_type_uint16List(v, &host_nodes, name, errp);
+}
+
+static void
+set_host_nodes(Object *obj, Visitor *v, void *opaque, const char *name,
+               Error **errp)
+{
+    HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(obj);
+    uint16List *l = NULL;
+
+    visit_type_uint16List(v, &l, name, errp);
+
+    while (l) {
+        bitmap_set(ram_backend->host_nodes, l->value, 1);
+        l = l->next;
+    }
+}
+
+static const char *policies[HOST_MEM_POLICY_MAX + 1] = {
+    [HOST_MEM_POLICY_DEFAULT] = "default",
+    [HOST_MEM_POLICY_PREFERRED] = "preferred",
+    [HOST_MEM_POLICY_MEMBIND] = "membind",
+    [HOST_MEM_POLICY_INTERLEAVE] = "interleave",
+    [HOST_MEM_POLICY_MAX] = NULL,
+};
+
+static void
+get_policy(Object *obj, Visitor *v, void *opaque, const char *name,
+           Error **errp)
+{
+    HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(obj);
+    int policy = ram_backend->policy;
+
+    visit_type_enum(v, &policy, policies, NULL, name, errp);
+}
+
+static void
+set_policy(Object *obj, Visitor *v, void *opaque, const char *name,
+           Error **errp)
+{
+    HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(obj);
+    int policy;
+
+    visit_type_enum(v, &policy, policies, NULL, name, errp);
+    ram_backend->policy = policy;
+}
+
+
+static bool get_relative(Object *obj, Error **errp)
+{
+    HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(obj);
+
+    return ram_backend->relative;
+}
+
+static void set_relative(Object *obj, bool value, Error **errp)
+{
+    HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(obj);
+
+    ram_backend->relative = value;
+}
+
+#include <sys/syscall.h>
+#ifndef MPOL_F_RELATIVE_NODES
+#define MPOL_F_RELATIVE_NODES (1 << 14)
+#define MPOL_F_STATIC_NODES   (1 << 15)
+#endif
 
 static int
 ram_backend_memory_init(HostMemoryBackend *backend, Error **errp)
 {
+    HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(backend);
+    int mode = ram_backend->policy;
+    void *p;
+    unsigned long maxnode;
+
     if (!memory_region_size(&backend->mr)) {
         memory_region_init_ram(&backend->mr, OBJECT(backend),
                                object_get_canonical_path(OBJECT(backend)),
                                backend->size);
+
+        p = memory_region_get_ram_ptr(&backend->mr);
+        maxnode = find_last_bit(ram_backend->host_nodes, MAX_NODES);
+
+        mode |= ram_backend->relative ? MPOL_F_RELATIVE_NODES :
+            MPOL_F_STATIC_NODES;
+
+        /* This is a workaround for a long standing bug in Linux'
+         * mbind implementation, which cuts off the last specified
+         * node. To stay compatible should this bug be fixed, we
+         * specify one more node and zero this one out.
+         */
+        if (syscall(SYS_mbind, p, backend->size, mode,
+                    ram_backend->host_nodes, maxnode + 2, 0)) {
+            return -1;
+        }
     }
 
     return 0;
 }
 
 static void
+ram_backend_initfn(Object *obj)
+{
+    object_property_add(obj, "host-nodes", "int",
+                        get_host_nodes,
+                        set_host_nodes, NULL, NULL, NULL);
+    object_property_add(obj, "policy", "string",
+                        get_policy,
+                        set_policy, NULL, NULL, NULL);
+    object_property_add_bool(obj, "relative",
+                             get_relative, set_relative, NULL);
+}
+
+static void
 ram_backend_class_init(ObjectClass *oc, void *data)
 {
     HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
@@ -38,6 +194,8 @@ static const TypeInfo ram_backend_info = {
     .name = TYPE_MEMORY_BACKEND_RAM,
     .parent = TYPE_MEMORY_BACKEND,
     .class_init = ram_backend_class_init,
+    .instance_size = sizeof(HostMemoryBackendRam),
+    .instance_init = ram_backend_initfn,
 };
 
 static void register_types(void)
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index acfc0c7..a3d8c02 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -152,6 +152,8 @@ void memory_region_allocate_system_memory(MemoryRegion *mr, 
Object *owner,
                                           const char *name,
                                           QEMUMachineInitArgs *args);
 
+extern QemuOptsList qemu_memdev_opts;
+
 #define MAX_OPTION_ROMS 16
 typedef struct QEMUOptionRom {
     const char *name;
-- 
1.8.5.2.229.g4448466