[PATCH v2 repost 2/7] virtio-balloon: define new feature bit and page bitmap head
From: Liang Li <hidden>
Date: 2016-07-27 01:31:17
Also in:
kvm, lkml, qemu-devel
Subsystem:
the rest, virtio balloon, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", David Hildenbrand, Jason Wang
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 <redacted> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Cornelia Huck <redacted> Cc: Amit Shah <redacted> --- 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 */
--
1.9.1
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>