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 <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>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
---
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
--
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