From c13c4153f76db23cac06a12044bf4dd346764059 Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Tue, 11 Dec 2018 16:24:53 +0800 Subject: 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 CC: Michael S. Tsirkin CC: Dr. David Alan Gilbert CC: Juan Quintela CC: Peter Xu Message-Id: <1544516693-5395-8-git-send-email-wei.w.wang@intel.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Dr. David Alan Gilbert dgilbert: Dropped kernel header update, fixed up CMD_ID_* name change --- include/hw/virtio/virtio-balloon.h | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h index 99dcd6d..1afafb1 100644 --- a/include/hw/virtio/virtio-balloon.h +++ b/include/hw/virtio/virtio-balloon.h @@ -17,11 +17,14 @@ #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 { @@ -32,15 +35,38 @@ typedef struct virtio_balloon_stat_modern { 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; + 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; -- cgit v1.1