hw/remote/memory.c

   1 /*
   2  * Memory manager for remote device
   3  *
   4  * Copyright © 2018, 2021 Oracle and/or its affiliates.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "qemu-common.h"
  13
  14 #include "hw/remote/memory.h"
  15 #include "exec/ram_addr.h"
  16 #include "qapi/error.h"
  17
  18 static void remote_sysmem_reset(void)
  19 {
  20     MemoryRegion *sysmem, *subregion, *next;
  21
  22     sysmem = get_system_memory();
  23
  24     QTAILQ_FOREACH_SAFE(subregion, &sysmem->subregions, subregions_link, next) {
  25         if (subregion->ram) {
  26             memory_region_del_subregion(sysmem, subregion);
  27             object_unparent(OBJECT(subregion));
  28         }
  29     }
  30 }
  31
  32 void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp)
  33 {
  34     ERRP_GUARD();
  35     SyncSysmemMsg *sysmem_info = &msg->data.sync_sysmem;
  36     MemoryRegion *sysmem, *subregion;
  37     static unsigned int suffix;
  38     int region;
  39
  40     sysmem = get_system_memory();
  41
  42     remote_sysmem_reset();
  43
  44     for (region = 0; region < msg->num_fds; region++) {
  45         g_autofree char *name;
  46         subregion = g_new(MemoryRegion, 1);
  47         name = g_strdup_printf("remote-mem-%u", suffix++);
  48         memory_region_init_ram_from_fd(subregion, NULL,
  49                                        name, sysmem_info->sizes[region],
  50                                        true, msg->fds[region],
  51                                        sysmem_info->offsets[region],
  52                                        errp);
  53
  54         if (*errp) {
  55             g_free(subregion);
  56             remote_sysmem_reset();
  57             return;
  58         }
  59
  60         memory_region_add_subregion(sysmem, sysmem_info->gpas[region],
  61                                     subregion);
  62
  63     }
  64 }