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/address-spaces.h"
  16 #include "exec/ram_addr.h"
  17 #include "qapi/error.h"
  18
  19 static void remote_sysmem_reset(void)
  20 {
  21     MemoryRegion *sysmem, *subregion, *next;
  22
  23     sysmem = get_system_memory();
  24
  25     QTAILQ_FOREACH_SAFE(subregion, &sysmem->subregions, subregions_link, next) {
  26         if (subregion->ram) {
  27             memory_region_del_subregion(sysmem, subregion);
  28             object_unparent(OBJECT(subregion));
  29         }
  30     }
  31 }
  32
  33 void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp)
  34 {
  35     ERRP_GUARD();
  36     SyncSysmemMsg *sysmem_info = &msg->data.sync_sysmem;
  37     MemoryRegion *sysmem, *subregion;
  38     static unsigned int suffix;
  39     int region;
  40
  41     sysmem = get_system_memory();
  42
  43     remote_sysmem_reset();
  44
  45     for (region = 0; region < msg->num_fds; region++) {
  46         g_autofree char *name;
  47         subregion = g_new(MemoryRegion, 1);
  48         name = g_strdup_printf("remote-mem-%u", suffix++);
  49         memory_region_init_ram_from_fd(subregion, NULL,
  50                                        name, sysmem_info->sizes[region],
  51                                        true, msg->fds[region],
  52                                        sysmem_info->offsets[region],
  53                                        errp);
  54
  55         if (*errp) {
  56             g_free(subregion);
  57             remote_sysmem_reset();
  58             return;
  59         }
  60
  61         memory_region_add_subregion(sysmem, sysmem_info->gpas[region],
  62                                     subregion);
  63
  64     }
  65 }