In case the word size of the domU and qemu running the qdisk backend differ BLKIF_OP_DISCARD will not work reliably, as the request structure in the ring have different layouts for different word size. Correct this by copying the request structure in case of different word size element by element in the BLKIF_OP_DISCARD case, too. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
147 lines
5.5 KiB
C
147 lines
5.5 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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/*
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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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*/
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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_request_discard {
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uint8_t operation; /* BLKIF_OP_DISCARD */
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uint8_t flag; /* nr_segments in request struct */
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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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uint64_t nr_sectors; /* # of contiguous sectors to discard */
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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_request_discard {
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uint8_t operation; /* BLKIF_OP_DISCARD */
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uint8_t flag; /* nr_segments in request struct */
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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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uint64_t nr_sectors; /* # of contiguous sectors to discard */
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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,
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struct blkif_common_response);
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DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
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struct blkif_x86_32_response);
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DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
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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_part;
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blkif_x86_64_back_ring_t x86_64_part;
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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 inline void blkif_get_x86_32_req(blkif_request_t *dst,
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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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/* Prevent the compiler from using src->... instead. */
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barrier();
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if (dst->operation == BLKIF_OP_DISCARD) {
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struct blkif_x86_32_request_discard *s = (void *)src;
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struct blkif_request_discard *d = (void *)dst;
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d->nr_sectors = s->nr_sectors;
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return;
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}
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if (n > dst->nr_segments) {
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n = dst->nr_segments;
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}
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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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}
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static inline void blkif_get_x86_64_req(blkif_request_t *dst,
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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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/* Prevent the compiler from using src->... instead. */
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barrier();
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if (dst->operation == BLKIF_OP_DISCARD) {
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struct blkif_x86_64_request_discard *s = (void *)src;
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struct blkif_request_discard *d = (void *)dst;
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d->nr_sectors = s->nr_sectors;
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return;
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}
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if (n > dst->nr_segments) {
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n = dst->nr_segments;
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}
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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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}
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#endif /* __XEN_BLKIF_H__ */
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