qemu/include/exec/ramlist.h
Peter Xu be9b23c4a5 ramblock: add new hmp command "info ramblock"
To dump information about ramblocks. It looks like:

(qemu) info ramblock
              Block Name    PSize              Offset               Used              Total
            /objects/mem    2 MiB  0x0000000000000000 0x0000000080000000 0x0000000080000000
                vga.vram    4 KiB  0x0000000080060000 0x0000000001000000 0x0000000001000000
    /rom@etc/acpi/tables    4 KiB  0x00000000810b0000 0x0000000000020000 0x0000000000200000
                 pc.bios    4 KiB  0x0000000080000000 0x0000000000040000 0x0000000000040000
  0000:00:03.0/e1000.rom    4 KiB  0x0000000081070000 0x0000000000040000 0x0000000000040000
                  pc.rom    4 KiB  0x0000000080040000 0x0000000000020000 0x0000000000020000
    0000:00:02.0/vga.rom    4 KiB  0x0000000081060000 0x0000000000010000 0x0000000000010000
   /rom@etc/table-loader    4 KiB  0x00000000812b0000 0x0000000000001000 0x0000000000001000
      /rom@etc/acpi/rsdp    4 KiB  0x00000000812b1000 0x0000000000001000 0x0000000000001000

Ramblock is something hidden internally in QEMU implementation, and this
command should only be used by mostly QEMU developers on RAM stuff. It
is not a command suitable for QMP interface. So only HMP interface is
provided for it.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1494562661-9063-4-git-send-email-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-05-17 17:31:16 +01:00

79 lines
2.6 KiB
C

#ifndef RAMLIST_H
#define RAMLIST_H
#include "qemu/queue.h"
#include "qemu/thread.h"
#include "qemu/rcu.h"
#include "qemu/rcu_queue.h"
typedef struct RAMBlockNotifier RAMBlockNotifier;
#define DIRTY_MEMORY_VGA 0
#define DIRTY_MEMORY_CODE 1
#define DIRTY_MEMORY_MIGRATION 2
#define DIRTY_MEMORY_NUM 3 /* num of dirty bits */
/* The dirty memory bitmap is split into fixed-size blocks to allow growth
* under RCU. The bitmap for a block can be accessed as follows:
*
* rcu_read_lock();
*
* DirtyMemoryBlocks *blocks =
* atomic_rcu_read(&ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION]);
*
* ram_addr_t idx = (addr >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
* unsigned long *block = blocks.blocks[idx];
* ...access block bitmap...
*
* rcu_read_unlock();
*
* Remember to check for the end of the block when accessing a range of
* addresses. Move on to the next block if you reach the end.
*
* Organization into blocks allows dirty memory to grow (but not shrink) under
* RCU. When adding new RAMBlocks requires the dirty memory to grow, a new
* DirtyMemoryBlocks array is allocated with pointers to existing blocks kept
* the same. Other threads can safely access existing blocks while dirty
* memory is being grown. When no threads are using the old DirtyMemoryBlocks
* anymore it is freed by RCU (but the underlying blocks stay because they are
* pointed to from the new DirtyMemoryBlocks).
*/
#define DIRTY_MEMORY_BLOCK_SIZE ((ram_addr_t)256 * 1024 * 8)
typedef struct {
struct rcu_head rcu;
unsigned long *blocks[];
} DirtyMemoryBlocks;
typedef struct RAMList {
QemuMutex mutex;
RAMBlock *mru_block;
/* RCU-enabled, writes protected by the ramlist lock. */
QLIST_HEAD(, RAMBlock) blocks;
DirtyMemoryBlocks *dirty_memory[DIRTY_MEMORY_NUM];
uint32_t version;
QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
} RAMList;
extern RAMList ram_list;
/* Should be holding either ram_list.mutex, or the RCU lock. */
#define RAMBLOCK_FOREACH(block) \
QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
void qemu_mutex_lock_ramlist(void);
void qemu_mutex_unlock_ramlist(void);
struct RAMBlockNotifier {
void (*ram_block_added)(RAMBlockNotifier *n, void *host, size_t size);
void (*ram_block_removed)(RAMBlockNotifier *n, void *host, size_t size);
QLIST_ENTRY(RAMBlockNotifier) next;
};
void ram_block_notifier_add(RAMBlockNotifier *n);
void ram_block_notifier_remove(RAMBlockNotifier *n);
void ram_block_notify_add(void *host, size_t size);
void ram_block_notify_remove(void *host, size_t size);
void ram_block_dump(Monitor *mon);
#endif /* RAMLIST_H */