LXR qemu/backends/hostmem-file.c

   1/*
   2 * QEMU Host Memory Backend for hugetlbfs
   3 *
   4 * Copyright (C) 2013-2014 Red Hat Inc
   5 *
   6 * Authors:
   7 *   Paolo Bonzini <pbonzini@redhat.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10 * See the COPYING file in the top-level directory.
  11 */
  12#include "qemu/osdep.h"
  13#include "qapi/error.h"
  14#include "qemu-common.h"
  15#include "sysemu/hostmem.h"
  16#include "sysemu/sysemu.h"
  17#include "qom/object_interfaces.h"
  18
  19/* hostmem-file.c */
  20/**
  21 * @TYPE_MEMORY_BACKEND_FILE:
  22 * name of backend that uses mmap on a file descriptor
  23 */
  24#define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"
  25
  26#define MEMORY_BACKEND_FILE(obj) \
  27    OBJECT_CHECK(HostMemoryBackendFile, (obj), TYPE_MEMORY_BACKEND_FILE)
  28
  29typedef struct HostMemoryBackendFile HostMemoryBackendFile;
  30
  31struct HostMemoryBackendFile {
  32    HostMemoryBackend parent_obj;
  33
  34    bool share;
  35    char *mem_path;
  36};
  37
  38static void
  39file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
  40{
  41    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
  42
  43    if (!backend->size) {
  44        error_setg(errp, "can't create backend with size 0");
  45        return;
  46    }
  47    if (!fb->mem_path) {
  48        error_setg(errp, "mem-path property not set");
  49        return;
  50    }
  51#ifndef CONFIG_LINUX
  52    error_setg(errp, "-mem-path not supported on this host");
  53#else
  54    if (!host_memory_backend_mr_inited(backend)) {
  55        gchar *path;
  56        backend->force_prealloc = mem_prealloc;
  57        path = object_get_canonical_path(OBJECT(backend));
  58        memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
  59                                 path,
  60                                 backend->size, fb->share,
  61                                 fb->mem_path, errp);
  62        g_free(path);
  63    }
  64#endif
  65}
  66
  67static char *get_mem_path(Object *o, Error **errp)
  68{
  69    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
  70
  71    return g_strdup(fb->mem_path);
  72}
  73
  74static void set_mem_path(Object *o, const char *str, Error **errp)
  75{
  76    HostMemoryBackend *backend = MEMORY_BACKEND(o);
  77    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
  78
  79    if (host_memory_backend_mr_inited(backend)) {
  80        error_setg(errp, "cannot change property value");
  81        return;
  82    }
  83    g_free(fb->mem_path);
  84    fb->mem_path = g_strdup(str);
  85}
  86
  87static bool file_memory_backend_get_share(Object *o, Error **errp)
  88{
  89    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
  90
  91    return fb->share;
  92}
  93
  94static void file_memory_backend_set_share(Object *o, bool value, Error **errp)
  95{
  96    HostMemoryBackend *backend = MEMORY_BACKEND(o);
  97    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
  98
  99    if (host_memory_backend_mr_inited(backend)) {
 100        error_setg(errp, "cannot change property value");
 101        return;
 102    }
 103    fb->share = value;
 104}
 105
 106static void
 107file_backend_class_init(ObjectClass *oc, void *data)
 108{
 109    HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
 110
 111    bc->alloc = file_backend_memory_alloc;
 112
 113    object_class_property_add_bool(oc, "share",
 114        file_memory_backend_get_share, file_memory_backend_set_share,
 115        &error_abort);
 116    object_class_property_add_str(oc, "mem-path",
 117        get_mem_path, set_mem_path,
 118        &error_abort);
 119}
 120
 121static void file_backend_instance_finalize(Object *o)
 122{
 123    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
 124
 125    g_free(fb->mem_path);
 126}
 127
 128static const TypeInfo file_backend_info = {
 129    .name = TYPE_MEMORY_BACKEND_FILE,
 130    .parent = TYPE_MEMORY_BACKEND,
 131    .class_init = file_backend_class_init,
 132    .instance_finalize = file_backend_instance_finalize,
 133    .instance_size = sizeof(HostMemoryBackendFile),
 134};
 135
 136static void register_types(void)
 137{
 138    type_register_static(&file_backend_info);
 139}
 140
 141type_init(register_types);
 142