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authorChangpeng Liu <changpeng.liu@intel.com>2018-11-02 01:40:35 +0300
committerMichael S. Tsirkin <mst@redhat.com>2018-12-20 02:23:49 +0300
commit1f23816b8eb8fdc39990abe166c10a18c16f6b21 (patch)
treea99e7e4494785aac1277f1848a9db07c443d4812 /include/uapi/linux/virtio_blk.h
parentc5c08bed843c2b2c048c16d1296d7631d7c1620e (diff)
downloadlinux-1f23816b8eb8fdc39990abe166c10a18c16f6b21.tar.xz
virtio_blk: add discard and write zeroes support
In commit 88c85538, "virtio-blk: add discard and write zeroes features to specification" (https://github.com/oasis-tcs/virtio-spec), the virtio block specification has been extended to add VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES commands. This patch enables support for discard and write zeroes in the virtio-blk driver when the device advertises the corresponding features, VIRTIO_BLK_F_DISCARD and VIRTIO_BLK_F_WRITE_ZEROES. Signed-off-by: Changpeng Liu <changpeng.liu@intel.com> Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'include/uapi/linux/virtio_blk.h')
-rw-r--r--include/uapi/linux/virtio_blk.h54
1 files changed, 54 insertions, 0 deletions
diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h
index 9ebe4d968dd5..0f99d7b49ede 100644
--- a/include/uapi/linux/virtio_blk.h
+++ b/include/uapi/linux/virtio_blk.h
@@ -38,6 +38,8 @@
#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
#define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */
#define VIRTIO_BLK_F_MQ 12 /* support more than one vq */
+#define VIRTIO_BLK_F_DISCARD 13 /* DISCARD is supported */
+#define VIRTIO_BLK_F_WRITE_ZEROES 14 /* WRITE ZEROES is supported */
/* Legacy feature bits */
#ifndef VIRTIO_BLK_NO_LEGACY
@@ -86,6 +88,39 @@ struct virtio_blk_config {
/* number of vqs, only available when VIRTIO_BLK_F_MQ is set */
__u16 num_queues;
+
+ /* the next 3 entries are guarded by VIRTIO_BLK_F_DISCARD */
+ /*
+ * The maximum discard sectors (in 512-byte sectors) for
+ * one segment.
+ */
+ __u32 max_discard_sectors;
+ /*
+ * The maximum number of discard segments in a
+ * discard command.
+ */
+ __u32 max_discard_seg;
+ /* Discard commands must be aligned to this number of sectors. */
+ __u32 discard_sector_alignment;
+
+ /* the next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES */
+ /*
+ * The maximum number of write zeroes sectors (in 512-byte sectors) in
+ * one segment.
+ */
+ __u32 max_write_zeroes_sectors;
+ /*
+ * The maximum number of segments in a write zeroes
+ * command.
+ */
+ __u32 max_write_zeroes_seg;
+ /*
+ * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the
+ * deallocation of one or more of the sectors.
+ */
+ __u8 write_zeroes_may_unmap;
+
+ __u8 unused1[3];
} __attribute__((packed));
/*
@@ -114,6 +149,12 @@ struct virtio_blk_config {
/* Get device ID command */
#define VIRTIO_BLK_T_GET_ID 8
+/* Discard command */
+#define VIRTIO_BLK_T_DISCARD 11
+
+/* Write zeroes command */
+#define VIRTIO_BLK_T_WRITE_ZEROES 13
+
#ifndef VIRTIO_BLK_NO_LEGACY
/* Barrier before this op. */
#define VIRTIO_BLK_T_BARRIER 0x80000000
@@ -133,6 +174,19 @@ struct virtio_blk_outhdr {
__virtio64 sector;
};
+/* Unmap this range (only valid for write zeroes command) */
+#define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001
+
+/* Discard/write zeroes range for each request. */
+struct virtio_blk_discard_write_zeroes {
+ /* discard/write zeroes start sector */
+ __le64 sector;
+ /* number of discard/write zeroes sectors */
+ __le32 num_sectors;
+ /* flags for this range */
+ __le32 flags;
+};
+
#ifndef VIRTIO_BLK_NO_LEGACY
struct virtio_scsi_inhdr {
__virtio32 errors;