Add a new feature which supports sending the page information with a bitmap. The current implementation uses PFNs array, which is not very efficient. Using bitmap can improve the performance of inflating/deflating significantly The page bitmap header will used to tell the host some information about the page bitmap. e.g. the page size, page bitmap length and start pfn. Signed-off-by: Liang Li <liang.z.li@xxxxxxxxx> Cc: Michael S. Tsirkin <mst@xxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: Cornelia Huck <cornelia.huck@xxxxxxxxxx> Cc: Amit Shah <amit.shah@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> --- include/uapi/linux/virtio_balloon.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index 343d7dd..d3b182a 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -34,6 +34,7 @@ #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ #define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */ #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ +#define VIRTIO_BALLOON_F_PAGE_BITMAP 3 /* Send page info with bitmap */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 @@ -82,4 +83,22 @@ struct virtio_balloon_stat { __virtio64 val; } __attribute__((packed)); +/* Page bitmap header structure */ +struct balloon_bmap_hdr { + /* Used to distinguish different request */ + __virtio16 cmd; + /* Shift width of page in the bitmap */ + __virtio16 page_shift; + /* flag used to identify different status */ + __virtio16 flag; + /* Reserved */ + __virtio16 reserved; + /* ID of the request */ + __virtio64 req_id; + /* The pfn of 0 bit in the bitmap */ + __virtio64 start_pfn; + /* The length of the bitmap, in bytes */ + __virtio64 bmap_len; +}; + #endif /* _LINUX_VIRTIO_BALLOON_H */ -- 1.8.3.1 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization