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| author | Christoph Hellwig <hch@lst.de> | 2010-02-24 14:22:25 -0600 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2010-02-24 14:22:26 +1030 |
| commit | 69740c8ba878f58bc3c71f74618fc2cd1da990da (patch) | |
| tree | 95a86d35fe234db2fd08b10cab0400ad1b2e56dd /include | |
| parent | d57ed95da483418e8b0433da693c9168dd0a2df6 (diff) | |
| download | linux-69740c8ba878f58bc3c71f74618fc2cd1da990da.tar.gz linux-69740c8ba878f58bc3c71f74618fc2cd1da990da.tar.bz2 linux-69740c8ba878f58bc3c71f74618fc2cd1da990da.zip | |
virtio_blk: add block topology support
Allow reading various alignment values from the config page. This
allows the guest to much better align I/O requests depending on the
storage topology.
Note that the formats for the config values appear a bit messed up,
but we follow the formats used by ATA and SCSI so they are expected in
the storage world.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/virtio_blk.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index fd294c56d571..e52029e98919 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -15,6 +15,7 @@ #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ #define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */ +#define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ struct virtio_blk_config { /* The capacity (in 512-byte sectors). */ @@ -29,8 +30,20 @@ struct virtio_blk_config { __u8 heads; __u8 sectors; } geometry; + /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ __u32 blk_size; + + /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ + /* exponent for physical block per logical block. */ + __u8 physical_block_exp; + /* alignment offset in logical blocks. */ + __u8 alignment_offset; + /* minimum I/O size without performance penalty in logical blocks. */ + __u16 min_io_size; + /* optimal sustained I/O size in logical blocks. */ + __u32 opt_io_size; + } __attribute__((packed)); /* |