qemu/include/exec/ramblock.h
Stefan Hajnoczi a4a411fbaf Replace "iothread lock" with "BQL" in comments
The term "iothread lock" is obsolete. The APIs use Big QEMU Lock (BQL)
in their names. Update the code comments to use "BQL" instead of
"iothread lock".

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Message-id: 20240102153529.486531-5-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2024-01-08 10:45:43 -05:00

81 lines
2.6 KiB
C

/*
* Declarations for cpu physical memory functions
*
* Copyright 2011 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Avi Kivity <avi@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*
*/
/*
* This header is for use by exec.c and memory.c ONLY. Do not include it.
* The functions declared here will be removed soon.
*/
#ifndef QEMU_EXEC_RAMBLOCK_H
#define QEMU_EXEC_RAMBLOCK_H
#ifndef CONFIG_USER_ONLY
#include "cpu-common.h"
#include "qemu/rcu.h"
#include "exec/ramlist.h"
struct RAMBlock {
struct rcu_head rcu;
struct MemoryRegion *mr;
uint8_t *host;
uint8_t *colo_cache; /* For colo, VM's ram cache */
ram_addr_t offset;
ram_addr_t used_length;
ram_addr_t max_length;
void (*resized)(const char*, uint64_t length, void *host);
uint32_t flags;
/* Protected by the BQL. */
char idstr[256];
/* RCU-enabled, writes protected by the ramlist lock */
QLIST_ENTRY(RAMBlock) next;
QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
int fd;
uint64_t fd_offset;
size_t page_size;
/* dirty bitmap used during migration */
unsigned long *bmap;
/* bitmap of already received pages in postcopy */
unsigned long *receivedmap;
/*
* bitmap to track already cleared dirty bitmap. When the bit is
* set, it means the corresponding memory chunk needs a log-clear.
* Set this up to non-NULL to enable the capability to postpone
* and split clearing of dirty bitmap on the remote node (e.g.,
* KVM). The bitmap will be set only when doing global sync.
*
* It is only used during src side of ram migration, and it is
* protected by the global ram_state.bitmap_mutex.
*
* NOTE: this bitmap is different comparing to the other bitmaps
* in that one bit can represent multiple guest pages (which is
* decided by the `clear_bmap_shift' variable below). On
* destination side, this should always be NULL, and the variable
* `clear_bmap_shift' is meaningless.
*/
unsigned long *clear_bmap;
uint8_t clear_bmap_shift;
/*
* RAM block length that corresponds to the used_length on the migration
* source (after RAM block sizes were synchronized). Especially, after
* starting to run the guest, used_length and postcopy_length can differ.
* Used to register/unregister uffd handlers and as the size of the received
* bitmap. Receiving any page beyond this length will bail out, as it
* could not have been valid on the source.
*/
ram_addr_t postcopy_length;
};
#endif
#endif