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...@intel.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: Cornelia Huck <cornelia.h...@de.ibm.com>
Cc: Amit Shah <amit.s...@redhat.com>
Cc: Dave Hansen <dave.han...@intel.com>
---
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..bed6f41 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));
+/* 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 */
+};
+
+/* Page bitmap header structure */
+struct virtio_balloon_bmap_hdr {
+ struct {
+ __le64 start_pfn : 52; /* start pfn for the bitmap */
+ __le64 page_shift : 6; /* page shift width, in bytes */
+ __le64 bmap_len : 6; /* bitmap length, in bytes */
+ } head;
+ __le64 bmap[0];
+};
+
#endif /* _LINUX_VIRTIO_BALLOON_H */
--
1.8.3.1
