[PATCH v6 kernel 2/5] virtio-balloon: define new feature bit and head struct
From: Liang Li <hidden>
Date: 2016-12-21 06:52:25
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 range array. The current implementation uses PFNs array, which is not very efficient. Using ranges can improve the performance of inflating/deflating significantly. 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> Cc: Dave Hansen <redacted> Cc: Andrea Arcangeli <redacted> Cc: David Hildenbrand <redacted> --- include/uapi/linux/virtio_balloon.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index 343d7dd..2f850bf 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h@@ -34,10 +34,14 @@ #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_RANGE 3 /* Send page info with ranges */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 +/* Bits width for the length of the pfn range */ +#define VIRTIO_BALLOON_NR_PFN_BITS 12 + struct virtio_balloon_config { /* Number of pages host wants Guest to give up. */ __u32 num_pages;
@@ -82,4 +86,12 @@ struct virtio_balloon_stat { __virtio64 val; } __attribute__((packed)); +/* Response header structure */ +struct virtio_balloon_resp_hdr { + __le64 cmd : 8; /* Distinguish different requests type */ + __le64 flag: 8; /* Mark status for a specific request type */ + __le64 id : 16; /* Distinguish requests of a specific type */ + __le64 data_len: 32; /* Length of the following data, in bytes */ +}; + #endif /* _LINUX_VIRTIO_BALLOON_H */
--
1.9.1