[PATCH v2 repost 5/7] virtio-balloon: define feature bit and head for misc virt queue
From: Liang Li <hidden>
Date: 2016-07-27 01:32:23
Also in:
kvm, lkml, qemu-devel
Subsystem:
the rest, virtio balloon, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", David Hildenbrand, Jason Wang
Define a new feature bit which supports a new virtual queue. This new virtual qeuque is for information exchange between hypervisor and guest. The VMM hypervisor can make use of this virtual queue to request the guest do some operations, e.g. drop page cache, synchronize file system, etc. And the VMM hypervisor can get some of guest's runtime information through this virtual queue, e.g. the guest's free page information, which can be used for live migration optimization. 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 | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index d3b182a..be4880f 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h@@ -35,6 +35,7 @@ #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 */ +#define VIRTIO_BALLOON_F_MISC_VQ 4 /* Misc info virtqueue */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12
@@ -101,4 +102,25 @@ struct balloon_bmap_hdr { __virtio64 bmap_len; }; +enum balloon_req_id { + /* Get free pages information */ + BALLOON_GET_FREE_PAGES, +}; + +enum balloon_flag { + /* Have more data for a request */ + BALLOON_FLAG_CONT, + /* No more data for a request */ + BALLOON_FLAG_DONE, +}; + +struct balloon_req_hdr { + /* Used to distinguish different request */ + __virtio16 cmd; + /* Reserved */ + __virtio16 reserved[3]; + /* Request parameter */ + __virtio64 param; +}; + #endif /* _LINUX_VIRTIO_BALLOON_H */
--
1.9.1
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