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/*
* 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.
*
*/
#ifndef SYSTEM_RAMBLOCK_H
#define SYSTEM_RAMBLOCK_H
#include "exec/cpu-common.h"
#include "qemu/rcu.h"
#include "exec/ramlist.h"
#include "system/hostmem.h"
#define TYPE_RAM_BLOCK_ATTRIBUTES "ram-block-attributes"
OBJECT_DECLARE_SIMPLE_TYPE(RamBlockAttributes, RAM_BLOCK_ATTRIBUTES)
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;
Error *cpr_blocker;
int fd;
uint64_t fd_offset;
int guest_memfd;
RamBlockAttributes *attributes;
size_t page_size;
/* dirty bitmap used during migration */
unsigned long *bmap;
/*
* Below fields are only used by mapped-ram migration
*/
/* bitmap of pages present in the migration file */
unsigned long *file_bmap;
/*
* offset in the file pages belonging to this ramblock are saved,
* used only during migration to a file.
*/
off_t bitmap_offset;
uint64_t pages_offset;
/* Bitmap of already received pages. Only used on destination side. */
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;
};
struct RamBlockAttributes {
Object parent;
RAMBlock *ram_block;
/* 1-setting of the bitmap represents ram is populated (shared) */
unsigned bitmap_size;
unsigned long *bitmap;
QLIST_HEAD(, RamDiscardListener) rdl_list;
};
/* @offset: the offset within the RAMBlock */
int ram_block_discard_range(RAMBlock *rb, uint64_t offset, size_t length);
/* @offset: the offset within the RAMBlock */
int ram_block_discard_guest_memfd_range(RAMBlock *rb, uint64_t offset,
size_t length);
RamBlockAttributes *ram_block_attributes_create(RAMBlock *ram_block);
void ram_block_attributes_destroy(RamBlockAttributes *attr);
int ram_block_attributes_state_change(RamBlockAttributes *attr, uint64_t offset,
uint64_t size, bool to_discard);
/**
* ram_block_is_pmem: Whether the RAM block is of persistent memory
*/
bool ram_block_is_pmem(RAMBlock *rb);
static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
{
return b && b->host && (offset < b->used_length);
}
static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
{
assert(offset_in_ramblock(block, offset));
return (char *)block->host + offset;
}
#endif
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