This patch adds a block device backend driver to qemu. It is a pure userspace implemention using the gntdev interface. It uses "qdisk" as backend name in xenstore so it doesn't interfere with the other existing backends (blkback aka "vbd" and tapdisk aka "tap"). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7223 c046a42c-6fe2-441c-8c8c-71466251a162
104 lines
3.5 KiB
C
104 lines
3.5 KiB
C
#ifndef __XEN_BLKIF_H__
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#define __XEN_BLKIF_H__
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#include <xen/io/ring.h>
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#include <xen/io/blkif.h>
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#include <xen/io/protocols.h>
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/* Not a real protocol. Used to generate ring structs which contain
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* the elements common to all protocols only. This way we get a
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* compiler-checkable way to use common struct elements, so we can
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* avoid using switch(protocol) in a number of places. */
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struct blkif_common_request {
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char dummy;
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};
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struct blkif_common_response {
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char dummy;
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};
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/* i386 protocol version */
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#pragma pack(push, 4)
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struct blkif_x86_32_request {
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uint8_t operation; /* BLKIF_OP_??? */
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uint8_t nr_segments; /* number of segments */
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blkif_vdev_t handle; /* only for read/write requests */
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uint64_t id; /* private guest value, echoed in resp */
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blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
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struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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};
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struct blkif_x86_32_response {
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uint64_t id; /* copied from request */
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uint8_t operation; /* copied from request */
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int16_t status; /* BLKIF_RSP_??? */
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};
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typedef struct blkif_x86_32_request blkif_x86_32_request_t;
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typedef struct blkif_x86_32_response blkif_x86_32_response_t;
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#pragma pack(pop)
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/* x86_64 protocol version */
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struct blkif_x86_64_request {
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uint8_t operation; /* BLKIF_OP_??? */
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uint8_t nr_segments; /* number of segments */
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blkif_vdev_t handle; /* only for read/write requests */
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uint64_t __attribute__((__aligned__(8))) id;
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blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
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struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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};
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struct blkif_x86_64_response {
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uint64_t __attribute__((__aligned__(8))) id;
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uint8_t operation; /* copied from request */
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int16_t status; /* BLKIF_RSP_??? */
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};
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typedef struct blkif_x86_64_request blkif_x86_64_request_t;
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typedef struct blkif_x86_64_response blkif_x86_64_response_t;
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DEFINE_RING_TYPES(blkif_common, struct blkif_common_request, struct blkif_common_response);
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DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request, struct blkif_x86_32_response);
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DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request, struct blkif_x86_64_response);
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union blkif_back_rings {
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blkif_back_ring_t native;
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blkif_common_back_ring_t common;
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blkif_x86_32_back_ring_t x86_32;
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blkif_x86_64_back_ring_t x86_64;
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};
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typedef union blkif_back_rings blkif_back_rings_t;
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enum blkif_protocol {
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BLKIF_PROTOCOL_NATIVE = 1,
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BLKIF_PROTOCOL_X86_32 = 2,
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BLKIF_PROTOCOL_X86_64 = 3,
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};
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static void inline blkif_get_x86_32_req(blkif_request_t *dst, blkif_x86_32_request_t *src)
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{
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int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
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dst->operation = src->operation;
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dst->nr_segments = src->nr_segments;
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dst->handle = src->handle;
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dst->id = src->id;
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dst->sector_number = src->sector_number;
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if (n > src->nr_segments)
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n = src->nr_segments;
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for (i = 0; i < n; i++)
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dst->seg[i] = src->seg[i];
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}
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static void inline blkif_get_x86_64_req(blkif_request_t *dst, blkif_x86_64_request_t *src)
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{
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int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
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dst->operation = src->operation;
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dst->nr_segments = src->nr_segments;
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dst->handle = src->handle;
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dst->id = src->id;
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dst->sector_number = src->sector_number;
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if (n > src->nr_segments)
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n = src->nr_segments;
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for (i = 0; i < n; i++)
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dst->seg[i] = src->seg[i];
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}
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#endif /* __XEN_BLKIF_H__ */
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