From 97e36834f5a106459ab1b290e663a4eb6264639e Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 12 Oct 2011 12:12:36 -0400 Subject: xen/blk[front|back]: Squash blkif_request_rw and blkif_request_discard together In a union type structure to deal with the overlapping attributes in a easier manner. Suggested-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- include/xen/interface/io/blkif.h | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'include/xen') diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h index 9324488f23f0..f88e28b6a27c 100644 --- a/include/xen/interface/io/blkif.h +++ b/include/xen/interface/io/blkif.h @@ -95,6 +95,12 @@ typedef uint64_t blkif_sector_t; #define BLKIF_MAX_SEGMENTS_PER_REQUEST 11 struct blkif_request_rw { + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t handle; /* only for read/write requests */ +#ifdef CONFIG_X86_64 + uint32_t _pad1; /* offsetof(blkif_request,u.rw.id) == 8 */ +#endif + uint64_t id; /* private guest value, echoed in resp */ blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ struct blkif_request_segment { grant_ref_t gref; /* reference to I/O buffer frame */ @@ -102,23 +108,27 @@ struct blkif_request_rw { /* @last_sect: last sector in frame to transfer (inclusive). */ uint8_t first_sect, last_sect; } seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; -}; +} __attribute__((__packed__)); struct blkif_request_discard { + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t _pad1; /* only for read/write requests */ +#ifdef CONFIG_X86_64 + uint32_t _pad2; /* offsetof(blkif_req..,u.discard.id)==8*/ +#endif + uint64_t id; /* private guest value, echoed in resp */ blkif_sector_t sector_number; - uint64_t nr_sectors; -}; + uint64_t nr_sectors; + uint8_t _pad3; +} __attribute__((__packed__)); struct blkif_request { uint8_t operation; /* BLKIF_OP_??? */ - uint8_t nr_segments; /* number of segments */ - blkif_vdev_t handle; /* only for read/write requests */ - uint64_t id; /* private guest value, echoed in resp */ union { struct blkif_request_rw rw; struct blkif_request_discard discard; } u; -}; +} __attribute__((__packed__)); struct blkif_response { uint64_t id; /* copied from request */ -- cgit v1.2.3 From 5ea42986694a96542644f9cae8b122d3a00c508f Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 12 Oct 2011 16:23:30 -0400 Subject: xen/blk[front|back]: Enhance discard support with secure erasing support. Part of the blkdev_issue_discard(xx) operation is that it can also issue a secure discard operation that will permanantly remove the sectors in question. We advertise that we can support that via the 'discard-secure' attribute and on the request, if the 'secure' bit is set, we will attempt to pass in REQ_DISCARD | REQ_SECURE. CC: Li Dongyang [v1: Used 'flag' instead of 'secure:1' bit] [v2: Use 'reserved' uint8_t instead of adding a new value] [v3: Check for nseg when mapping instead of operation] Signed-off-by: Konrad Rzeszutek Wilk --- include/xen/interface/io/blkif.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'include/xen') diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h index f88e28b6a27c..ee338bfde18b 100644 --- a/include/xen/interface/io/blkif.h +++ b/include/xen/interface/io/blkif.h @@ -84,6 +84,21 @@ typedef uint64_t blkif_sector_t; * e07154r6-Data_Set_Management_Proposal_for_ATA-ACS2.doc * http://www.seagate.com/staticfiles/support/disc/manuals/ * Interface%20manuals/100293068c.pdf + * The backend can optionally provide three extra XenBus attributes to + * further optimize the discard functionality: + * 'discard-aligment' - Devices that support discard functionality may + * internally allocate space in units that are bigger than the exported + * logical block size. The discard-alignment parameter indicates how many bytes + * the beginning of the partition is offset from the internal allocation unit's + * natural alignment. + * 'discard-granularity' - Devices that support discard functionality may + * internally allocate space using units that are bigger than the logical block + * size. The discard-granularity parameter indicates the size of the internal + * allocation unit in bytes if reported by the device. Otherwise the + * discard-granularity will be set to match the device's physical block size. + * 'discard-secure' - All copies of the discarded sectors (potentially created + * by garbage collection) must also be erased. To use this feature, the flag + * BLKIF_DISCARD_SECURE must be set in the blkif_request_trim. */ #define BLKIF_OP_DISCARD 5 @@ -111,7 +126,8 @@ struct blkif_request_rw { } __attribute__((__packed__)); struct blkif_request_discard { - uint8_t nr_segments; /* number of segments */ + uint8_t flag; /* BLKIF_DISCARD_SECURE or zero. */ +#define BLKIF_DISCARD_SECURE (1<<0) /* ignored if discard-secure=0 */ blkif_vdev_t _pad1; /* only for read/write requests */ #ifdef CONFIG_X86_64 uint32_t _pad2; /* offsetof(blkif_req..,u.discard.id)==8*/ -- cgit v1.2.3