xemu/block/block-ram-registrar.c
Stefan Hajnoczi 7f9241d805 block: add BlockRAMRegistrar
Emulated devices and other BlockBackend users wishing to take advantage
of blk_register_buf() all have the same repetitive job: register
RAMBlocks with the BlockBackend using RAMBlockNotifier.

Add a BlockRAMRegistrar API to do this. A later commit will use this
from hw/block/virtio-blk.c.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20221013185908.1297568-10-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-26 14:56:42 -04:00

59 lines
1.5 KiB
C

/*
* BlockBackend RAM Registrar
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "sysemu/block-backend.h"
#include "sysemu/block-ram-registrar.h"
#include "qapi/error.h"
static void ram_block_added(RAMBlockNotifier *n, void *host, size_t size,
size_t max_size)
{
BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier);
Error *err = NULL;
if (!r->ok) {
return; /* don't try again if we've already failed */
}
if (!blk_register_buf(r->blk, host, max_size, &err)) {
error_report_err(err);
ram_block_notifier_remove(&r->notifier);
r->ok = false;
}
}
static void ram_block_removed(RAMBlockNotifier *n, void *host, size_t size,
size_t max_size)
{
BlockRAMRegistrar *r = container_of(n, BlockRAMRegistrar, notifier);
blk_unregister_buf(r->blk, host, max_size);
}
void blk_ram_registrar_init(BlockRAMRegistrar *r, BlockBackend *blk)
{
r->blk = blk;
r->notifier = (RAMBlockNotifier){
.ram_block_added = ram_block_added,
.ram_block_removed = ram_block_removed,
/*
* .ram_block_resized() is not necessary because we use the max_size
* value that does not change across resize.
*/
};
r->ok = true;
ram_block_notifier_add(&r->notifier);
}
void blk_ram_registrar_destroy(BlockRAMRegistrar *r)
{
if (r->ok) {
ram_block_notifier_remove(&r->notifier);
}
}