block/block-ram-registrar.c

   1 /*
   2  * BlockBackend RAM Registrar
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-or-later
   5  */
   6
   7 #include "qemu/osdep.h"
   8 #include "sysemu/block-backend.h"
   9 #include "sysemu/block-ram-registrar.h"
  10 #include "qapi/error.h"
  11
  12 static void ram_block_added(RAMBlockNotifier *n, void *host, size_t size,
  13                             size_t max_size)
  14 {
  15     BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier);
  16     Error *err = NULL;
  17
  18     if (!r->ok) {
  19         return; /* don't try again if we've already failed */
  20     }
  21
  22     if (!blk_register_buf(r->blk, host, max_size, &err)) {
  23         error_report_err(err);
  24         ram_block_notifier_remove(&r->notifier);
  25         r->ok = false;
  26     }
  27 }
  28
  29 static void ram_block_removed(RAMBlockNotifier *n, void *host, size_t size,
  30                               size_t max_size)
  31 {
  32     BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier);
  33     blk_unregister_buf(r->blk, host, max_size);
  34 }
  35
  36 void blk_ram_registrar_init(BlockRAMRegistrar *r, BlockBackend *blk)
  37 {
  38     r->blk = blk;
  39     r->notifier = (RAMBlockNotifier){
  40         .ram_block_added = ram_block_added,
  41         .ram_block_removed = ram_block_removed,
  42
  43         /*
  44          * .ram_block_resized() is not necessary because we use the max_size
  45          * value that does not change across resize.
  46          */
  47     };
  48     r->ok = true;
  49
  50     ram_block_notifier_add(&r->notifier);
  51 }
  52
  53 void blk_ram_registrar_destroy(BlockRAMRegistrar *r)
  54 {
  55     if (r->ok) {
  56         ram_block_notifier_remove(&r->notifier);
  57     }
  58 }