acrn-hypervisor/devicemodel/include/block_if.h

126 lines
4.9 KiB
C

/*-
* Copyright (c) 2013 Peter Grehan <grehan@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* The block API to be used by acrn-dm block-device emulations. The routines
* are thread safe, with no assumptions about the context of the completion
* callback - it may occur in the caller's context, or asynchronously in
* another thread.
*/
#ifndef _BLOCK_IF_H_
#define _BLOCK_IF_H_
#include <sys/uio.h>
#include <sys/unistd.h>
#include "iothread.h"
#define BLOCKIF_IOV_MAX 256 /* not practical to be IOV_MAX */
/*
* |<------------------------------------- bounced_size --------------------------------->|
* |<-------- alignment ------->| |<-------- alignment ------->|
* |<--- head --->|<------------------------ org_size ---------------------->|<-- tail -->|
* | | | | | |
* *--------------$-------------*----------- ... ------------*---------------$------------*
* | | | | | |
* | start end |
* aligned_dn_start aligned_dn_end
* |__________head_area_________| |__________tail_area_________|
* |<--- head --->| | |<-- end_rmd -->|<-- tail -->|
* |<-------- alignment ------->| |<-------- alignment ------->|
*
*/
struct br_align_info {
uint32_t alignment;
bool is_iov_base_aligned;
bool is_iov_len_aligned;
bool is_offset_aligned;
/*
* Needs to convert the misaligned request to an aligned one when
* O_DIRECT is used, but the request (either buffer address/length, or offset) is not aligned.
*/
bool need_conversion;
uint32_t head;
uint32_t tail;
uint32_t org_size;
uint32_t bounced_size;
off_t aligned_dn_start;
off_t aligned_dn_end;
/*
* A bounce_iov for aligned read/write access.
* bounce_iov.iov_base is aligned to @alignment
* bounce_iov.iov_len is @bounced_size (@head + @org_size + @tail)
*/
struct iovec bounce_iov;
};
struct blockif_req {
struct iovec iov[BLOCKIF_IOV_MAX];
int iovcnt;
off_t offset;
ssize_t resid;
void (*callback)(struct blockif_req *req, int err);
void *param;
int qidx;
struct br_align_info align_info;
};
struct blockif_ctxt;
struct blockif_ctxt *blockif_open(const char *optstr, const char *ident, int queue_num,
struct iothreads_info *iothrds_info);
off_t blockif_size(struct blockif_ctxt *bc);
void blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h,
uint8_t *s);
int blockif_sectsz(struct blockif_ctxt *bc);
void blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off);
int blockif_queuesz(struct blockif_ctxt *bc);
int blockif_is_ro(struct blockif_ctxt *bc);
int blockif_candiscard(struct blockif_ctxt *bc);
int blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq);
int blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq);
int blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq);
int blockif_discard(struct blockif_ctxt *bc, struct blockif_req *breq);
int blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq);
int blockif_close(struct blockif_ctxt *bc);
uint8_t blockif_get_wce(struct blockif_ctxt *bc);
void blockif_set_wce(struct blockif_ctxt *bc, uint8_t wce);
int blockif_flush_all(struct blockif_ctxt *bc);
int blockif_max_discard_sectors(struct blockif_ctxt *bc);
int blockif_max_discard_seg(struct blockif_ctxt *bc);
int blockif_discard_sector_alignment(struct blockif_ctxt *bc);
#endif /* _BLOCK_IF_H_ */