786 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			786 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 *  xen paravirt block device backend
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 *
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						|
 *  (c) Gerd Hoffmann <kraxel@redhat.com>
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 *
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						|
 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
 | 
						|
 *  the Free Software Foundation; under version 2 of the License.
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						|
 *
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						|
 *  This program is distributed in the hope that it will be useful,
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						|
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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						|
 *  GNU General Public License for more details.
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 *
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 *  You should have received a copy of the GNU General Public License along
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						|
 *  with this program; if not, write to the Free Software Foundation, Inc.,
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 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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 */
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 | 
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#include <stdio.h>
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#include <stdlib.h>
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						|
#include <stdarg.h>
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						|
#include <string.h>
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						|
#include <unistd.h>
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						|
#include <signal.h>
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						|
#include <inttypes.h>
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						|
#include <time.h>
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						|
#include <fcntl.h>
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						|
#include <errno.h>
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						|
#include <sys/ioctl.h>
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						|
#include <sys/types.h>
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						|
#include <sys/stat.h>
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						|
#include <sys/mman.h>
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						|
#include <sys/uio.h>
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						|
 | 
						|
#include <xs.h>
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						|
#include <xenctrl.h>
 | 
						|
#include <xen/io/xenbus.h>
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						|
 | 
						|
#include "hw.h"
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						|
#include "block_int.h"
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						|
#include "qemu-char.h"
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						|
#include "xen_blkif.h"
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						|
#include "xen_backend.h"
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						|
 | 
						|
/* ------------------------------------------------------------- */
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						|
 | 
						|
static int syncwrite    = 0;
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						|
static int batch_maps   = 0;
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						|
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static int max_requests = 32;
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						|
static int use_aio      = 1;
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						|
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/* ------------------------------------------------------------- */
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#define BLOCK_SIZE  512
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						|
#define IOCB_COUNT  (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2)
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 | 
						|
struct ioreq {
 | 
						|
    blkif_request_t     req;
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						|
    int16_t             status;
 | 
						|
 | 
						|
    /* parsed request */
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						|
    off_t               start;
 | 
						|
    QEMUIOVector        v;
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						|
    int                 presync;
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						|
    int                 postsync;
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						|
 | 
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    /* grant mapping */
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						|
    uint32_t            domids[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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						|
    uint32_t            refs[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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    int                 prot;
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    void                *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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    void                *pages;
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						|
 | 
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    /* aio status */
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						|
    int                 aio_inflight;
 | 
						|
    int                 aio_errors;
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						|
 | 
						|
    struct XenBlkDev    *blkdev;
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						|
    LIST_ENTRY(ioreq)   list;
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						|
};
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 | 
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struct XenBlkDev {
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						|
    struct XenDevice    xendev;  /* must be first */
 | 
						|
    char                *params;
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						|
    char                *mode;
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    char                *type;
 | 
						|
    char                *dev;
 | 
						|
    char                *devtype;
 | 
						|
    const char          *fileproto;
 | 
						|
    const char          *filename;
 | 
						|
    int                 ring_ref;
 | 
						|
    void                *sring;
 | 
						|
    int64_t             file_blk;
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						|
    int64_t             file_size;
 | 
						|
    int                 protocol;
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						|
    blkif_back_rings_t  rings;
 | 
						|
    int                 more_work;
 | 
						|
    int                 cnt_map;
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						|
 | 
						|
    /* request lists */
 | 
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    LIST_HEAD(inflight_head, ioreq) inflight;
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						|
    LIST_HEAD(finished_head, ioreq) finished;
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						|
    LIST_HEAD(freelist_head, ioreq) freelist;
 | 
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    int                 requests_total;
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    int                 requests_inflight;
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						|
    int                 requests_finished;
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						|
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    /* qemu block driver */
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						|
    int                 index;
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    BlockDriverState    *bs;
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						|
    QEMUBH              *bh;
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						|
};
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/* ------------------------------------------------------------- */
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static struct ioreq *ioreq_start(struct XenBlkDev *blkdev)
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{
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    struct ioreq *ioreq = NULL;
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						|
    if (LIST_EMPTY(&blkdev->freelist)) {
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						|
	if (blkdev->requests_total >= max_requests)
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	    goto out;
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	/* allocate new struct */
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	ioreq = qemu_mallocz(sizeof(*ioreq));
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	ioreq->blkdev = blkdev;
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	blkdev->requests_total++;
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        qemu_iovec_init(&ioreq->v, BLKIF_MAX_SEGMENTS_PER_REQUEST);
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    } else {
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	/* get one from freelist */
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	ioreq = LIST_FIRST(&blkdev->freelist);
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	LIST_REMOVE(ioreq, list);
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        qemu_iovec_reset(&ioreq->v);
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    }
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    LIST_INSERT_HEAD(&blkdev->inflight, ioreq, list);
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    blkdev->requests_inflight++;
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out:
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						|
    return ioreq;
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}
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static void ioreq_finish(struct ioreq *ioreq)
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{
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    struct XenBlkDev *blkdev = ioreq->blkdev;
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    LIST_REMOVE(ioreq, list);
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    LIST_INSERT_HEAD(&blkdev->finished, ioreq, list);
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    blkdev->requests_inflight--;
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    blkdev->requests_finished++;
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}
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static void ioreq_release(struct ioreq *ioreq)
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{
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    struct XenBlkDev *blkdev = ioreq->blkdev;
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    LIST_REMOVE(ioreq, list);
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    memset(ioreq, 0, sizeof(*ioreq));
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    ioreq->blkdev = blkdev;
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    LIST_INSERT_HEAD(&blkdev->freelist, ioreq, list);
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    blkdev->requests_finished--;
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}
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/*
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 * translate request into iovec + start offset
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 * do sanity checks along the way
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 */
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static int ioreq_parse(struct ioreq *ioreq)
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{
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    struct XenBlkDev *blkdev = ioreq->blkdev;
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    uintptr_t mem;
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    size_t len;
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    int i;
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    xen_be_printf(&blkdev->xendev, 3,
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		  "op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n",
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		  ioreq->req.operation, ioreq->req.nr_segments,
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		  ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number);
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    switch (ioreq->req.operation) {
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						|
    case BLKIF_OP_READ:
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						|
	ioreq->prot = PROT_WRITE; /* to memory */
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						|
        if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') {
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						|
	    xen_be_printf(&blkdev->xendev, 0, "error: write req for ro device\n");
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	    goto err;
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						|
	}
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	break;
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						|
    case BLKIF_OP_WRITE_BARRIER:
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						|
	if (!syncwrite)
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	    ioreq->presync = ioreq->postsync = 1;
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	/* fall through */
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						|
    case BLKIF_OP_WRITE:
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	ioreq->prot = PROT_READ; /* from memory */
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						|
	if (syncwrite)
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	    ioreq->postsync = 1;
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						|
	break;
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    default:
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	xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n",
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		      ioreq->req.operation);
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	goto err;
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    };
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    ioreq->start = ioreq->req.sector_number * blkdev->file_blk;
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						|
    for (i = 0; i < ioreq->req.nr_segments; i++) {
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						|
	if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
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						|
	    xen_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n");
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						|
	    goto err;
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	}
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						|
	if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) {
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						|
	    xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n");
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						|
	    goto err;
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						|
	}
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						|
	if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) {
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						|
	    xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n");
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						|
	    goto err;
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						|
	}
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	ioreq->domids[i] = blkdev->xendev.dom;
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	ioreq->refs[i]   = ioreq->req.seg[i].gref;
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	mem = ioreq->req.seg[i].first_sect * blkdev->file_blk;
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	len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk;
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        qemu_iovec_add(&ioreq->v, (void*)mem, len);
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    }
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    if (ioreq->start + ioreq->v.size > blkdev->file_size) {
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	xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n");
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	goto err;
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    }
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    return 0;
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err:
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    ioreq->status = BLKIF_RSP_ERROR;
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    return -1;
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}
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static void ioreq_unmap(struct ioreq *ioreq)
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						|
{
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						|
    int gnt = ioreq->blkdev->xendev.gnttabdev;
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						|
    int i;
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						|
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						|
    if (ioreq->v.niov == 0)
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						|
        return;
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						|
    if (batch_maps) {
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						|
	if (!ioreq->pages)
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						|
	    return;
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						|
	if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->v.niov) != 0)
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						|
	    xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n",
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						|
			  strerror(errno));
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						|
	ioreq->blkdev->cnt_map -= ioreq->v.niov;
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	ioreq->pages = NULL;
 | 
						|
    } else {
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						|
	for (i = 0; i < ioreq->v.niov; i++) {
 | 
						|
	    if (!ioreq->page[i])
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						|
		continue;
 | 
						|
	    if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0)
 | 
						|
		xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n",
 | 
						|
			      strerror(errno));
 | 
						|
	    ioreq->blkdev->cnt_map--;
 | 
						|
	    ioreq->page[i] = NULL;
 | 
						|
	}
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
static int ioreq_map(struct ioreq *ioreq)
 | 
						|
{
 | 
						|
    int gnt = ioreq->blkdev->xendev.gnttabdev;
 | 
						|
    int i;
 | 
						|
 | 
						|
    if (ioreq->v.niov == 0)
 | 
						|
        return 0;
 | 
						|
    if (batch_maps) {
 | 
						|
	ioreq->pages = xc_gnttab_map_grant_refs
 | 
						|
	    (gnt, ioreq->v.niov, ioreq->domids, ioreq->refs, ioreq->prot);
 | 
						|
	if (ioreq->pages == NULL) {
 | 
						|
	    xen_be_printf(&ioreq->blkdev->xendev, 0,
 | 
						|
			  "can't map %d grant refs (%s, %d maps)\n",
 | 
						|
			  ioreq->v.niov, strerror(errno), ioreq->blkdev->cnt_map);
 | 
						|
	    return -1;
 | 
						|
	}
 | 
						|
	for (i = 0; i < ioreq->v.niov; i++)
 | 
						|
	    ioreq->v.iov[i].iov_base = ioreq->pages + i * XC_PAGE_SIZE +
 | 
						|
		(uintptr_t)ioreq->v.iov[i].iov_base;
 | 
						|
	ioreq->blkdev->cnt_map += ioreq->v.niov;
 | 
						|
    } else  {
 | 
						|
	for (i = 0; i < ioreq->v.niov; i++) {
 | 
						|
	    ioreq->page[i] = xc_gnttab_map_grant_ref
 | 
						|
		(gnt, ioreq->domids[i], ioreq->refs[i], ioreq->prot);
 | 
						|
	    if (ioreq->page[i] == NULL) {
 | 
						|
		xen_be_printf(&ioreq->blkdev->xendev, 0,
 | 
						|
			      "can't map grant ref %d (%s, %d maps)\n",
 | 
						|
			      ioreq->refs[i], strerror(errno), ioreq->blkdev->cnt_map);
 | 
						|
		ioreq_unmap(ioreq);
 | 
						|
		return -1;
 | 
						|
	    }
 | 
						|
	    ioreq->v.iov[i].iov_base = ioreq->page[i] + (uintptr_t)ioreq->v.iov[i].iov_base;
 | 
						|
	    ioreq->blkdev->cnt_map++;
 | 
						|
	}
 | 
						|
    }
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static int ioreq_runio_qemu_sync(struct ioreq *ioreq)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = ioreq->blkdev;
 | 
						|
    int i, rc, len = 0;
 | 
						|
    off_t pos;
 | 
						|
 | 
						|
    if (ioreq_map(ioreq) == -1)
 | 
						|
	goto err;
 | 
						|
    if (ioreq->presync)
 | 
						|
	bdrv_flush(blkdev->bs);
 | 
						|
 | 
						|
    switch (ioreq->req.operation) {
 | 
						|
    case BLKIF_OP_READ:
 | 
						|
	pos = ioreq->start;
 | 
						|
	for (i = 0; i < ioreq->v.niov; i++) {
 | 
						|
	    rc = bdrv_read(blkdev->bs, pos / BLOCK_SIZE,
 | 
						|
			   ioreq->v.iov[i].iov_base,
 | 
						|
			   ioreq->v.iov[i].iov_len / BLOCK_SIZE);
 | 
						|
	    if (rc != 0) {
 | 
						|
		xen_be_printf(&blkdev->xendev, 0, "rd I/O error (%p, len %zd)\n",
 | 
						|
			      ioreq->v.iov[i].iov_base,
 | 
						|
			      ioreq->v.iov[i].iov_len);
 | 
						|
		goto err;
 | 
						|
	    }
 | 
						|
	    len += ioreq->v.iov[i].iov_len;
 | 
						|
	    pos += ioreq->v.iov[i].iov_len;
 | 
						|
	}
 | 
						|
	break;
 | 
						|
    case BLKIF_OP_WRITE:
 | 
						|
    case BLKIF_OP_WRITE_BARRIER:
 | 
						|
	pos = ioreq->start;
 | 
						|
	for (i = 0; i < ioreq->v.niov; i++) {
 | 
						|
	    rc = bdrv_write(blkdev->bs, pos / BLOCK_SIZE,
 | 
						|
			    ioreq->v.iov[i].iov_base,
 | 
						|
			    ioreq->v.iov[i].iov_len / BLOCK_SIZE);
 | 
						|
	    if (rc != 0) {
 | 
						|
		xen_be_printf(&blkdev->xendev, 0, "wr I/O error (%p, len %zd)\n",
 | 
						|
			      ioreq->v.iov[i].iov_base,
 | 
						|
			      ioreq->v.iov[i].iov_len);
 | 
						|
		goto err;
 | 
						|
	    }
 | 
						|
	    len += ioreq->v.iov[i].iov_len;
 | 
						|
	    pos += ioreq->v.iov[i].iov_len;
 | 
						|
	}
 | 
						|
	break;
 | 
						|
    default:
 | 
						|
	/* unknown operation (shouldn't happen -- parse catches this) */
 | 
						|
	goto err;
 | 
						|
    }
 | 
						|
 | 
						|
    if (ioreq->postsync)
 | 
						|
	bdrv_flush(blkdev->bs);
 | 
						|
    ioreq->status = BLKIF_RSP_OKAY;
 | 
						|
 | 
						|
    ioreq_unmap(ioreq);
 | 
						|
    ioreq_finish(ioreq);
 | 
						|
    return 0;
 | 
						|
 | 
						|
err:
 | 
						|
    ioreq->status = BLKIF_RSP_ERROR;
 | 
						|
    return -1;
 | 
						|
}
 | 
						|
 | 
						|
static void qemu_aio_complete(void *opaque, int ret)
 | 
						|
{
 | 
						|
    struct ioreq *ioreq = opaque;
 | 
						|
 | 
						|
    if (ret != 0) {
 | 
						|
        xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n",
 | 
						|
                      ioreq->req.operation == BLKIF_OP_READ ? "read" : "write");
 | 
						|
        ioreq->aio_errors++;
 | 
						|
    }
 | 
						|
 | 
						|
    ioreq->aio_inflight--;
 | 
						|
    if (ioreq->aio_inflight > 0)
 | 
						|
        return;
 | 
						|
 | 
						|
    ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY;
 | 
						|
    ioreq_unmap(ioreq);
 | 
						|
    ioreq_finish(ioreq);
 | 
						|
    qemu_bh_schedule(ioreq->blkdev->bh);
 | 
						|
}
 | 
						|
 | 
						|
static int ioreq_runio_qemu_aio(struct ioreq *ioreq)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = ioreq->blkdev;
 | 
						|
 | 
						|
    if (ioreq_map(ioreq) == -1)
 | 
						|
	goto err;
 | 
						|
 | 
						|
    ioreq->aio_inflight++;
 | 
						|
    if (ioreq->presync)
 | 
						|
	bdrv_flush(blkdev->bs); /* FIXME: aio_flush() ??? */
 | 
						|
 | 
						|
    switch (ioreq->req.operation) {
 | 
						|
    case BLKIF_OP_READ:
 | 
						|
        ioreq->aio_inflight++;
 | 
						|
        bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE,
 | 
						|
                       &ioreq->v, ioreq->v.size / BLOCK_SIZE,
 | 
						|
                       qemu_aio_complete, ioreq);
 | 
						|
	break;
 | 
						|
    case BLKIF_OP_WRITE:
 | 
						|
    case BLKIF_OP_WRITE_BARRIER:
 | 
						|
        ioreq->aio_inflight++;
 | 
						|
        bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE,
 | 
						|
                        &ioreq->v, ioreq->v.size / BLOCK_SIZE,
 | 
						|
                        qemu_aio_complete, ioreq);
 | 
						|
	break;
 | 
						|
    default:
 | 
						|
	/* unknown operation (shouldn't happen -- parse catches this) */
 | 
						|
	goto err;
 | 
						|
    }
 | 
						|
 | 
						|
    if (ioreq->postsync)
 | 
						|
	bdrv_flush(blkdev->bs); /* FIXME: aio_flush() ??? */
 | 
						|
    qemu_aio_complete(ioreq, 0);
 | 
						|
 | 
						|
    return 0;
 | 
						|
 | 
						|
err:
 | 
						|
    ioreq->status = BLKIF_RSP_ERROR;
 | 
						|
    return -1;
 | 
						|
}
 | 
						|
 | 
						|
static int blk_send_response_one(struct ioreq *ioreq)
 | 
						|
{
 | 
						|
    struct XenBlkDev  *blkdev = ioreq->blkdev;
 | 
						|
    int               send_notify   = 0;
 | 
						|
    int               have_requests = 0;
 | 
						|
    blkif_response_t  resp;
 | 
						|
    void              *dst;
 | 
						|
 | 
						|
    resp.id        = ioreq->req.id;
 | 
						|
    resp.operation = ioreq->req.operation;
 | 
						|
    resp.status    = ioreq->status;
 | 
						|
 | 
						|
    /* Place on the response ring for the relevant domain. */
 | 
						|
    switch (blkdev->protocol) {
 | 
						|
    case BLKIF_PROTOCOL_NATIVE:
 | 
						|
	dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt);
 | 
						|
	break;
 | 
						|
    case BLKIF_PROTOCOL_X86_32:
 | 
						|
        dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part,
 | 
						|
                                blkdev->rings.x86_32_part.rsp_prod_pvt);
 | 
						|
	break;
 | 
						|
    case BLKIF_PROTOCOL_X86_64:
 | 
						|
        dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part,
 | 
						|
                                blkdev->rings.x86_64_part.rsp_prod_pvt);
 | 
						|
	break;
 | 
						|
    default:
 | 
						|
	dst = NULL;
 | 
						|
    }
 | 
						|
    memcpy(dst, &resp, sizeof(resp));
 | 
						|
    blkdev->rings.common.rsp_prod_pvt++;
 | 
						|
 | 
						|
    RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify);
 | 
						|
    if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
 | 
						|
	/*
 | 
						|
	 * Tail check for pending requests. Allows frontend to avoid
 | 
						|
	 * notifications if requests are already in flight (lower
 | 
						|
	 * overheads and promotes batching).
 | 
						|
	 */
 | 
						|
	RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests);
 | 
						|
    } else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) {
 | 
						|
	have_requests = 1;
 | 
						|
    }
 | 
						|
 | 
						|
    if (have_requests)
 | 
						|
	blkdev->more_work++;
 | 
						|
    return send_notify;
 | 
						|
}
 | 
						|
 | 
						|
/* walk finished list, send outstanding responses, free requests */
 | 
						|
static void blk_send_response_all(struct XenBlkDev *blkdev)
 | 
						|
{
 | 
						|
    struct ioreq *ioreq;
 | 
						|
    int send_notify = 0;
 | 
						|
 | 
						|
    while (!LIST_EMPTY(&blkdev->finished)) {
 | 
						|
        ioreq = LIST_FIRST(&blkdev->finished);
 | 
						|
	send_notify += blk_send_response_one(ioreq);
 | 
						|
	ioreq_release(ioreq);
 | 
						|
    }
 | 
						|
    if (send_notify)
 | 
						|
	xen_be_send_notify(&blkdev->xendev);
 | 
						|
}
 | 
						|
 | 
						|
static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc)
 | 
						|
{
 | 
						|
    switch (blkdev->protocol) {
 | 
						|
    case BLKIF_PROTOCOL_NATIVE:
 | 
						|
	memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc),
 | 
						|
	       sizeof(ioreq->req));
 | 
						|
	break;
 | 
						|
    case BLKIF_PROTOCOL_X86_32:
 | 
						|
        blkif_get_x86_32_req(&ioreq->req,
 | 
						|
                             RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc));
 | 
						|
	break;
 | 
						|
    case BLKIF_PROTOCOL_X86_64:
 | 
						|
        blkif_get_x86_64_req(&ioreq->req,
 | 
						|
                             RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc));
 | 
						|
	break;
 | 
						|
    }
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static void blk_handle_requests(struct XenBlkDev *blkdev)
 | 
						|
{
 | 
						|
    RING_IDX rc, rp;
 | 
						|
    struct ioreq *ioreq;
 | 
						|
 | 
						|
    blkdev->more_work = 0;
 | 
						|
 | 
						|
    rc = blkdev->rings.common.req_cons;
 | 
						|
    rp = blkdev->rings.common.sring->req_prod;
 | 
						|
    xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
 | 
						|
 | 
						|
    if (use_aio)
 | 
						|
        blk_send_response_all(blkdev);
 | 
						|
    while (rc != rp) {
 | 
						|
        /* pull request from ring */
 | 
						|
        if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc))
 | 
						|
            break;
 | 
						|
        ioreq = ioreq_start(blkdev);
 | 
						|
        if (ioreq == NULL) {
 | 
						|
            blkdev->more_work++;
 | 
						|
            break;
 | 
						|
        }
 | 
						|
        blk_get_request(blkdev, ioreq, rc);
 | 
						|
        blkdev->rings.common.req_cons = ++rc;
 | 
						|
 | 
						|
        /* parse them */
 | 
						|
        if (ioreq_parse(ioreq) != 0) {
 | 
						|
            if (blk_send_response_one(ioreq))
 | 
						|
                xen_be_send_notify(&blkdev->xendev);
 | 
						|
            ioreq_release(ioreq);
 | 
						|
            continue;
 | 
						|
        }
 | 
						|
 | 
						|
        if (use_aio) {
 | 
						|
            /* run i/o in aio mode */
 | 
						|
            ioreq_runio_qemu_aio(ioreq);
 | 
						|
        } else {
 | 
						|
            /* run i/o in sync mode */
 | 
						|
            ioreq_runio_qemu_sync(ioreq);
 | 
						|
        }
 | 
						|
    }
 | 
						|
    if (!use_aio)
 | 
						|
        blk_send_response_all(blkdev);
 | 
						|
 | 
						|
    if (blkdev->more_work && blkdev->requests_inflight < max_requests)
 | 
						|
        qemu_bh_schedule(blkdev->bh);
 | 
						|
}
 | 
						|
 | 
						|
/* ------------------------------------------------------------- */
 | 
						|
 | 
						|
static void blk_bh(void *opaque)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = opaque;
 | 
						|
    blk_handle_requests(blkdev);
 | 
						|
}
 | 
						|
 | 
						|
static void blk_alloc(struct XenDevice *xendev)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
 | 
						|
 | 
						|
    LIST_INIT(&blkdev->inflight);
 | 
						|
    LIST_INIT(&blkdev->finished);
 | 
						|
    LIST_INIT(&blkdev->freelist);
 | 
						|
    blkdev->bh = qemu_bh_new(blk_bh, blkdev);
 | 
						|
    if (xen_mode != XEN_EMULATE)
 | 
						|
        batch_maps = 1;
 | 
						|
}
 | 
						|
 | 
						|
static int blk_init(struct XenDevice *xendev)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
 | 
						|
    int mode, qflags, have_barriers, info = 0;
 | 
						|
    char *h;
 | 
						|
 | 
						|
    /* read xenstore entries */
 | 
						|
    if (blkdev->params == NULL) {
 | 
						|
	blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params");
 | 
						|
        h = strchr(blkdev->params, ':');
 | 
						|
	if (h != NULL) {
 | 
						|
	    blkdev->fileproto = blkdev->params;
 | 
						|
	    blkdev->filename  = h+1;
 | 
						|
	    *h = 0;
 | 
						|
	} else {
 | 
						|
	    blkdev->fileproto = "<unset>";
 | 
						|
	    blkdev->filename  = blkdev->params;
 | 
						|
	}
 | 
						|
    }
 | 
						|
    if (blkdev->mode == NULL)
 | 
						|
	blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
 | 
						|
    if (blkdev->type == NULL)
 | 
						|
	blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type");
 | 
						|
    if (blkdev->dev == NULL)
 | 
						|
	blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev");
 | 
						|
    if (blkdev->devtype == NULL)
 | 
						|
	blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type");
 | 
						|
 | 
						|
    /* do we have all we need? */
 | 
						|
    if (blkdev->params == NULL ||
 | 
						|
	blkdev->mode == NULL   ||
 | 
						|
	blkdev->type == NULL   ||
 | 
						|
	blkdev->dev == NULL)
 | 
						|
	return -1;
 | 
						|
 | 
						|
    /* read-only ? */
 | 
						|
    if (strcmp(blkdev->mode, "w") == 0) {
 | 
						|
	mode   = O_RDWR;
 | 
						|
	qflags = BDRV_O_RDWR;
 | 
						|
    } else {
 | 
						|
	mode   = O_RDONLY;
 | 
						|
	qflags = BDRV_O_RDONLY;
 | 
						|
	info  |= VDISK_READONLY;
 | 
						|
    }
 | 
						|
 | 
						|
    /* cdrom ? */
 | 
						|
    if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom"))
 | 
						|
	info  |= VDISK_CDROM;
 | 
						|
 | 
						|
    /* init qemu block driver */
 | 
						|
    blkdev->index = (blkdev->xendev.dev - 202 * 256) / 16;
 | 
						|
    blkdev->index = drive_get_index(IF_XEN, 0, blkdev->index);
 | 
						|
    if (blkdev->index == -1) {
 | 
						|
        /* setup via xenbus -> create new block driver instance */
 | 
						|
        xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n");
 | 
						|
	blkdev->bs = bdrv_new(blkdev->dev);
 | 
						|
	if (blkdev->bs) {
 | 
						|
	    if (bdrv_open2(blkdev->bs, blkdev->filename, qflags,
 | 
						|
                           bdrv_find_format(blkdev->fileproto)) != 0) {
 | 
						|
		bdrv_delete(blkdev->bs);
 | 
						|
		blkdev->bs = NULL;
 | 
						|
	    }
 | 
						|
	}
 | 
						|
	if (!blkdev->bs)
 | 
						|
	    return -1;
 | 
						|
    } else {
 | 
						|
        /* setup via qemu cmdline -> already setup for us */
 | 
						|
        xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n");
 | 
						|
	blkdev->bs = drives_table[blkdev->index].bdrv;
 | 
						|
    }
 | 
						|
    blkdev->file_blk  = BLOCK_SIZE;
 | 
						|
    blkdev->file_size = bdrv_getlength(blkdev->bs);
 | 
						|
    if (blkdev->file_size < 0) {
 | 
						|
        xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n",
 | 
						|
                      (int)blkdev->file_size, strerror(-blkdev->file_size),
 | 
						|
                      blkdev->bs->drv ? blkdev->bs->drv->format_name : "-");
 | 
						|
	blkdev->file_size = 0;
 | 
						|
    }
 | 
						|
    have_barriers = blkdev->bs->drv && blkdev->bs->drv->bdrv_flush ? 1 : 0;
 | 
						|
 | 
						|
    xen_be_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\","
 | 
						|
		  " size %" PRId64 " (%" PRId64 " MB)\n",
 | 
						|
		  blkdev->type, blkdev->fileproto, blkdev->filename,
 | 
						|
		  blkdev->file_size, blkdev->file_size >> 20);
 | 
						|
 | 
						|
    /* fill info */
 | 
						|
    xenstore_write_be_int(&blkdev->xendev, "feature-barrier", have_barriers);
 | 
						|
    xenstore_write_be_int(&blkdev->xendev, "info",            info);
 | 
						|
    xenstore_write_be_int(&blkdev->xendev, "sector-size",     blkdev->file_blk);
 | 
						|
    xenstore_write_be_int(&blkdev->xendev, "sectors",
 | 
						|
			  blkdev->file_size / blkdev->file_blk);
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static int blk_connect(struct XenDevice *xendev)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
 | 
						|
 | 
						|
    if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1)
 | 
						|
	return -1;
 | 
						|
    if (xenstore_read_fe_int(&blkdev->xendev, "event-channel",
 | 
						|
                             &blkdev->xendev.remote_port) == -1)
 | 
						|
	return -1;
 | 
						|
 | 
						|
    blkdev->protocol = BLKIF_PROTOCOL_NATIVE;
 | 
						|
    if (blkdev->xendev.protocol) {
 | 
						|
        if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0)
 | 
						|
            blkdev->protocol = BLKIF_PROTOCOL_X86_32;
 | 
						|
        if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0)
 | 
						|
            blkdev->protocol = BLKIF_PROTOCOL_X86_64;
 | 
						|
    }
 | 
						|
 | 
						|
    blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev,
 | 
						|
					    blkdev->xendev.dom,
 | 
						|
					    blkdev->ring_ref,
 | 
						|
					    PROT_READ | PROT_WRITE);
 | 
						|
    if (!blkdev->sring)
 | 
						|
	return -1;
 | 
						|
    blkdev->cnt_map++;
 | 
						|
 | 
						|
    switch (blkdev->protocol) {
 | 
						|
    case BLKIF_PROTOCOL_NATIVE:
 | 
						|
    {
 | 
						|
	blkif_sring_t *sring_native = blkdev->sring;
 | 
						|
	BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_SIZE);
 | 
						|
	break;
 | 
						|
    }
 | 
						|
    case BLKIF_PROTOCOL_X86_32:
 | 
						|
    {
 | 
						|
	blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring;
 | 
						|
 | 
						|
        BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, XC_PAGE_SIZE);
 | 
						|
	break;
 | 
						|
    }
 | 
						|
    case BLKIF_PROTOCOL_X86_64:
 | 
						|
    {
 | 
						|
	blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring;
 | 
						|
 | 
						|
        BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, XC_PAGE_SIZE);
 | 
						|
	break;
 | 
						|
    }
 | 
						|
    }
 | 
						|
 | 
						|
    xen_be_bind_evtchn(&blkdev->xendev);
 | 
						|
 | 
						|
    xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, "
 | 
						|
		  "remote port %d, local port %d\n",
 | 
						|
		  blkdev->xendev.protocol, blkdev->ring_ref,
 | 
						|
		  blkdev->xendev.remote_port, blkdev->xendev.local_port);
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static void blk_disconnect(struct XenDevice *xendev)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
 | 
						|
 | 
						|
    if (blkdev->bs) {
 | 
						|
        if (blkdev->index == -1) {
 | 
						|
            /* close/delete only if we created it ourself */
 | 
						|
            bdrv_close(blkdev->bs);
 | 
						|
            bdrv_delete(blkdev->bs);
 | 
						|
        }
 | 
						|
	blkdev->bs = NULL;
 | 
						|
    }
 | 
						|
    xen_be_unbind_evtchn(&blkdev->xendev);
 | 
						|
 | 
						|
    if (blkdev->sring) {
 | 
						|
	xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1);
 | 
						|
	blkdev->cnt_map--;
 | 
						|
	blkdev->sring = NULL;
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
static int blk_free(struct XenDevice *xendev)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
 | 
						|
    struct ioreq *ioreq;
 | 
						|
 | 
						|
    while (!LIST_EMPTY(&blkdev->freelist)) {
 | 
						|
	ioreq = LIST_FIRST(&blkdev->freelist);
 | 
						|
        LIST_REMOVE(ioreq, list);
 | 
						|
        qemu_iovec_destroy(&ioreq->v);
 | 
						|
	qemu_free(ioreq);
 | 
						|
    }
 | 
						|
 | 
						|
    qemu_free(blkdev->params);
 | 
						|
    qemu_free(blkdev->mode);
 | 
						|
    qemu_free(blkdev->type);
 | 
						|
    qemu_free(blkdev->dev);
 | 
						|
    qemu_free(blkdev->devtype);
 | 
						|
    qemu_bh_delete(blkdev->bh);
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static void blk_event(struct XenDevice *xendev)
 | 
						|
{
 | 
						|
    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
 | 
						|
 | 
						|
    qemu_bh_schedule(blkdev->bh);
 | 
						|
}
 | 
						|
 | 
						|
struct XenDevOps xen_blkdev_ops = {
 | 
						|
    .size       = sizeof(struct XenBlkDev),
 | 
						|
    .flags      = DEVOPS_FLAG_NEED_GNTDEV,
 | 
						|
    .alloc      = blk_alloc,
 | 
						|
    .init       = blk_init,
 | 
						|
    .connect    = blk_connect,
 | 
						|
    .disconnect = blk_disconnect,
 | 
						|
    .event      = blk_event,
 | 
						|
    .free       = blk_free,
 | 
						|
};
 |