qemu/include/hw/virtio/virtio-balloon.h
Wei Wang c13c4153f7 virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT
The new feature enables the virtio-balloon device to receive hints of
guest free pages from the free page vq.

A notifier is registered to the migration precopy notifier chain. The
notifier calls free_page_start after the migration thread syncs the dirty
bitmap, so that the free page optimization starts to clear bits of free
pages from the bitmap. It calls the free_page_stop before the migration
thread syncs the bitmap, which is the end of the current round of ram
save. The free_page_stop is also called to stop the optimization in the
case when there is an error occurred in the process of ram saving.

Note: balloon will report pages which were free at the time of this call.
As the reporting happens asynchronously, dirty bit logging must be
enabled before this free_page_start call is made. Guest reporting must be
disabled before the migration dirty bitmap is synchronized.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
CC: Michael S. Tsirkin <mst@redhat.com>
CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Peter Xu <peterx@redhat.com>
Message-Id: <1544516693-5395-8-git-send-email-wei.w.wang@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Dropped kernel header update, fixed up CMD_ID_* name change
2019-03-06 10:49:18 +00:00

77 lines
2.0 KiB
C

/*
* Virtio Support
*
* Copyright IBM, Corp. 2007-2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
* Rusty Russell <rusty@rustcorp.com.au>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#ifndef QEMU_VIRTIO_BALLOON_H
#define QEMU_VIRTIO_BALLOON_H
#include "standard-headers/linux/virtio_balloon.h"
#include "hw/virtio/virtio.h"
#include "sysemu/iothread.h"
#define TYPE_VIRTIO_BALLOON "virtio-balloon-device"
#define VIRTIO_BALLOON(obj) \
OBJECT_CHECK(VirtIOBalloon, (obj), TYPE_VIRTIO_BALLOON)
#define VIRTIO_BALLOON_FREE_PAGE_REPORT_CMD_ID_MIN 0x80000000
typedef struct virtio_balloon_stat VirtIOBalloonStat;
typedef struct virtio_balloon_stat_modern {
uint16_t tag;
uint8_t reserved[6];
uint64_t val;
} VirtIOBalloonStatModern;
typedef struct PartiallyBalloonedPage PartiallyBalloonedPage;
enum virtio_balloon_free_page_report_status {
FREE_PAGE_REPORT_S_STOP = 0,
FREE_PAGE_REPORT_S_REQUESTED = 1,
FREE_PAGE_REPORT_S_START = 2,
FREE_PAGE_REPORT_S_DONE = 3,
};
typedef struct VirtIOBalloon {
VirtIODevice parent_obj;
VirtQueue *ivq, *dvq, *svq, *free_page_vq;
uint32_t free_page_report_status;
uint32_t num_pages;
uint32_t actual;
uint32_t free_page_report_cmd_id;
uint64_t stats[VIRTIO_BALLOON_S_NR];
VirtQueueElement *stats_vq_elem;
size_t stats_vq_offset;
QEMUTimer *stats_timer;
IOThread *iothread;
QEMUBH *free_page_bh;
/*
* Lock to synchronize threads to access the free page reporting related
* fields (e.g. free_page_report_status).
*/
QemuMutex free_page_lock;
QemuCond free_page_cond;
/*
* Set to block iothread to continue reading free page hints as the VM is
* stopped.
*/
bool block_iothread;
NotifierWithReturn free_page_report_notify;
int64_t stats_last_update;
int64_t stats_poll_interval;
uint32_t host_features;
PartiallyBalloonedPage *pbp;
} VirtIOBalloon;
#endif