diff options
Diffstat (limited to 'src/hw/block/xen_blkif.h')
| -rw-r--r-- | src/hw/block/xen_blkif.h | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/src/hw/block/xen_blkif.h b/src/hw/block/xen_blkif.h new file mode 100644 index 0000000..c68487cb --- /dev/null +++ b/src/hw/block/xen_blkif.h @@ -0,0 +1,119 @@ +#ifndef __XEN_BLKIF_H__ +#define __XEN_BLKIF_H__ + +#include <xen/io/ring.h> +#include <xen/io/blkif.h> +#include <xen/io/protocols.h> + +/* Not a real protocol. Used to generate ring structs which contain + * the elements common to all protocols only. This way we get a + * compiler-checkable way to use common struct elements, so we can + * avoid using switch(protocol) in a number of places. */ +struct blkif_common_request { + char dummy; +}; +struct blkif_common_response { + char dummy; +}; + +/* i386 protocol version */ +#pragma pack(push, 4) +struct blkif_x86_32_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 */ + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; +}; +struct blkif_x86_32_response { + uint64_t id; /* copied from request */ + uint8_t operation; /* copied from request */ + int16_t status; /* BLKIF_RSP_??? */ +}; +typedef struct blkif_x86_32_request blkif_x86_32_request_t; +typedef struct blkif_x86_32_response blkif_x86_32_response_t; +#pragma pack(pop) + +/* x86_64 protocol version */ +struct blkif_x86_64_request { + uint8_t operation; /* BLKIF_OP_??? */ + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t handle; /* only for read/write requests */ + uint64_t __attribute__((__aligned__(8))) id; + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; +}; +struct blkif_x86_64_response { + uint64_t __attribute__((__aligned__(8))) id; + uint8_t operation; /* copied from request */ + int16_t status; /* BLKIF_RSP_??? */ +}; +typedef struct blkif_x86_64_request blkif_x86_64_request_t; +typedef struct blkif_x86_64_response blkif_x86_64_response_t; + +DEFINE_RING_TYPES(blkif_common, struct blkif_common_request, struct blkif_common_response); +DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request, struct blkif_x86_32_response); +DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request, struct blkif_x86_64_response); + +union blkif_back_rings { + blkif_back_ring_t native; + blkif_common_back_ring_t common; + blkif_x86_32_back_ring_t x86_32_part; + blkif_x86_64_back_ring_t x86_64_part; +}; +typedef union blkif_back_rings blkif_back_rings_t; + +enum blkif_protocol { + BLKIF_PROTOCOL_NATIVE = 1, + BLKIF_PROTOCOL_X86_32 = 2, + BLKIF_PROTOCOL_X86_64 = 3, +}; + +static inline void blkif_get_x86_32_req(blkif_request_t *dst, blkif_x86_32_request_t *src) +{ + int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; + + dst->operation = src->operation; + dst->nr_segments = src->nr_segments; + dst->handle = src->handle; + dst->id = src->id; + dst->sector_number = src->sector_number; + if (src->operation == BLKIF_OP_DISCARD) { + struct blkif_request_discard *s = (void *)src; + struct blkif_request_discard *d = (void *)dst; + d->nr_sectors = s->nr_sectors; + return; + } + /* prevent the compiler from optimizing the code and using src->nr_segments instead */ + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; + for (i = 0; i < n; i++) + dst->seg[i] = src->seg[i]; +} + +static inline void blkif_get_x86_64_req(blkif_request_t *dst, blkif_x86_64_request_t *src) +{ + int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; + + dst->operation = src->operation; + dst->nr_segments = src->nr_segments; + dst->handle = src->handle; + dst->id = src->id; + dst->sector_number = src->sector_number; + if (src->operation == BLKIF_OP_DISCARD) { + struct blkif_request_discard *s = (void *)src; + struct blkif_request_discard *d = (void *)dst; + d->nr_sectors = s->nr_sectors; + return; + } + /* prevent the compiler from optimizing the code and using src->nr_segments instead */ + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; + for (i = 0; i < n; i++) + dst->seg[i] = src->seg[i]; +} + +#endif /* __XEN_BLKIF_H__ */ |
