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