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/*
* xen_segment.c
*/
#include <xeno/config.h>
#include <xeno/types.h>
#include <xeno/lib.h>
#include <asm/io.h>
#include <xeno/slab.h>
#include <xeno/segment.h>
#include <xeno/sched.h>
#include <xeno/blkdev.h>
#include <xeno/keyhandler.h>
#include <asm/current.h>
#include <asm/domain_page.h>
#include <hypervisor-ifs/block.h>
segment_t xsegments[XEN_MAX_SEGMENTS];
/*
* xen_segment_map_request
*
* xen_device must be a valid device.
*/
/*
* NB. Al offsets and sizes here are in sector units.
* eg. 'size == 1' means an actual size of 512 bytes.
*/
int xen_segment_map_request(
phys_seg_t *pseg, struct task_struct *p, int operation,
unsigned short segment_number,
unsigned long sect_nr, unsigned long buffer, unsigned short nr_sects)
{
segment_t *seg;
extent_t *ext;
int sum, i;
if ( segment_number >= XEN_MAX_SEGMENTS ) goto fail;
seg = p->segment_list[segment_number];
if ( seg == NULL ) goto fail;
/* check domain permissions */
if ( seg->domain != p->domain ) goto fail;
/* check rw access */
if ((operation == WRITE && seg->mode != XEN_SEGMENT_RW) ||
(operation == READ && seg->mode == XEN_SEGMENT_UNUSED))
goto fail;
/* find extent, check size */
sum = 0;
i = 0;
ext = seg->extents;
while ( (i < seg->num_extents) && ((sum + ext->size) <= sect_nr) )
{
sum += ext->size;
ext++; i++;
}
if ( (sum + ext->size) <= sect_nr ) goto fail;
pseg->sector_number = sect_nr + ext->offset - sum;
pseg->buffer = buffer;
pseg->nr_sects = nr_sects;
pseg->dev = xendev_to_physdev(ext->disk);
if ( pseg->dev == 0 ) goto fail;
/* We're finished if the virtual extent didn't overrun the phys extent. */
if ( (sum + ext->size) >= (sect_nr + nr_sects) )
return 1; /* Just one more physical extent. */
/* Hmmm... make sure there's another extent to overrun onto! */
if ( (i+1) == seg->num_extents ) goto fail;
pseg[1].nr_sects = (sect_nr + nr_sects) - (sum + ext->size);
pseg[0].nr_sects = sum + ext->size - sect_nr;
pseg[1].buffer = buffer + (pseg->nr_sects << 9);
pseg[1].sector_number = ext[1].offset;
pseg[1].dev = xendev_to_physdev(ext[1].disk);
if ( pseg[1].dev == 0 ) goto fail;
/* We don't allow overrun onto a third physical extent. */
if ( (sum + ext[0].size + ext[1].size) <
(pseg[1].sector_number + pseg[1].nr_sects) )
goto fail;
return 2; /* We overran onto a second physical es\xtent. */
fail:
return -1;
}
/*
* xen_segment_probe
*
* return a list of segments to the guestos
*/
void xen_segment_probe(struct task_struct *p, xen_disk_info_t *raw_xdi)
{
int loop, i;
xen_disk_info_t *xdi = map_domain_mem(virt_to_phys(raw_xdi));
for ( loop = 0; loop < XEN_MAX_SEGMENTS; loop++ )
{
if ( (xsegments[loop].mode == XEN_SEGMENT_UNUSED) ||
(xsegments[loop].domain != p->domain) )
continue;
xdi->disks[xdi->count].device =
MK_VIRTUAL_XENDEV(xsegments[loop].segment_number);
for ( i = 0; i < xsegments[loop].num_extents; i++ )
{
xdi->disks[xdi->count].capacity +=
xsegments[loop].extents[i].size;
}
xdi->count++;
}
unmap_domain_mem(xdi);
}
/*
* xen_refresh_segment_list
*
* find all segments associated with a domain and assign
* them to the domain
*/
void xen_refresh_segment_list (struct task_struct *p)
{
int loop;
for (loop = 0; loop < XEN_MAX_SEGMENTS; loop++)
{
if ( (xsegments[loop].mode == XEN_SEGMENT_UNUSED) ||
(xsegments[loop].domain != p->domain) )
continue;
p->segment_list[xsegments[loop].segment_number] = &xsegments[loop];
p->segment_count++;
}
}
/*
* create a new segment for a domain
*
* return 0 on success, 1 on failure
*
* TODO: need to check to see if the DOM#/SEG# combination
* already exists. if so, reuse the slot in the segment table.
*/
int xen_segment_create(xv_disk_t *xvd_in)
{
int idx;
int loop;
xv_disk_t *xvd = map_domain_mem(virt_to_phys(xvd_in));
for (idx = 0; idx < XEN_MAX_SEGMENTS; idx++)
{
if (xsegments[idx].mode == XEN_SEGMENT_UNUSED) break;
}
if (idx == XEN_MAX_SEGMENTS)
{
printk (KERN_ALERT "xen_segment_create: unable to find free slot\n");
unmap_domain_mem(xvd);
return 1;
}
xsegments[idx].mode = xvd->mode;
xsegments[idx].domain = xvd->domain;
xsegments[idx].segment_number = xvd->segment;
xsegments[idx].num_extents = xvd->ext_count;
xsegments[idx].extents = (extent_t *)kmalloc(
sizeof(extent_t)*xvd->ext_count,
GFP_KERNEL);
/* could memcpy, but this is safer */
for (loop = 0; loop < xvd->ext_count; loop++)
{
xsegments[idx].extents[loop].disk = xvd->extents[loop].disk;
xsegments[idx].extents[loop].offset = xvd->extents[loop].offset;
xsegments[idx].extents[loop].size = xvd->extents[loop].size;
if (xsegments[idx].extents[loop].size == 0)
{
printk("xen_segment_create: extent %d is zero length\n", loop);
unmap_domain_mem(xvd);
return 1;
}
}
unmap_domain_mem(xvd);
return 0;
}
/*
* delete a segment from a domain
*
* return 0 on success, 1 on failure
*
* TODO: caller must ensure that only domain 0 calls this function
*/
int xen_segment_delete(struct task_struct *p, xv_disk_t *xvd)
{
return 0;
}
static void dump_segments(u_char key, void *dev_id, struct pt_regs *regs)
{
int loop, i;
struct task_struct *p;
printk("segment list\n");
for (loop = 0; loop < XEN_MAX_SEGMENTS; loop++)
{
if (xsegments[loop].mode != XEN_SEGMENT_UNUSED)
{
printk(" %2d: %s dom%d, seg# %d, num_exts: %d\n",
loop,
xsegments[loop].mode == XEN_SEGMENT_RO ? "RO" : "RW",
xsegments[loop].domain, xsegments[loop].segment_number,
xsegments[loop].num_extents);
for (i = 0; i < xsegments[loop].num_extents; i++)
{
printk(" ext %d: disk %d, offset 0x%lx, size 0x%lx\n",
i, xsegments[loop].extents[i].disk,
xsegments[loop].extents[i].offset,
xsegments[loop].extents[i].size);
}
}
}
printk("segments by domain\n");
p = current->next_task;
do
{
printk(" domain: %d\n", p->domain);
for (loop = 0; loop < p->segment_count; loop++)
{
printk(" mode:%d domain:%d seg:%d exts:%d\n",
p->segment_list[loop]->mode,
p->segment_list[loop]->domain,
p->segment_list[loop]->segment_number,
p->segment_list[loop]->num_extents);
}
p = p->next_task;
} while (p != current);
}
/*
* initialize segments
*/
void xen_segment_initialize(void)
{
memset (xsegments, 0, sizeof(xsegments));
add_key_handler('S', dump_segments, "dump segments");
}
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