diff options
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/block/xen_disk.c | 153 |
1 files changed, 148 insertions, 5 deletions
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 3428689..5aa350a 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -119,6 +119,9 @@ struct XenBlkDev { unsigned int persistent_gnt_count; unsigned int max_grants; + /* Grant copy */ + gboolean feature_grant_copy; + /* qemu block driver */ DriveInfo *dinfo; BlockBackend *blk; @@ -489,6 +492,106 @@ static int ioreq_map(struct ioreq *ioreq) return 0; } +#if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 480 + +static void ioreq_free_copy_buffers(struct ioreq *ioreq) +{ + int i; + + for (i = 0; i < ioreq->v.niov; i++) { + ioreq->page[i] = NULL; + } + + qemu_vfree(ioreq->pages); +} + +static int ioreq_init_copy_buffers(struct ioreq *ioreq) +{ + int i; + + if (ioreq->v.niov == 0) { + return 0; + } + + ioreq->pages = qemu_memalign(XC_PAGE_SIZE, ioreq->v.niov * XC_PAGE_SIZE); + + for (i = 0; i < ioreq->v.niov; i++) { + ioreq->page[i] = ioreq->pages + i * XC_PAGE_SIZE; + ioreq->v.iov[i].iov_base = ioreq->page[i]; + } + + return 0; +} + +static int ioreq_grant_copy(struct ioreq *ioreq) +{ + xengnttab_handle *gnt = ioreq->blkdev->xendev.gnttabdev; + xengnttab_grant_copy_segment_t segs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + int i, count, rc; + int64_t file_blk = ioreq->blkdev->file_blk; + + if (ioreq->v.niov == 0) { + return 0; + } + + count = ioreq->v.niov; + + for (i = 0; i < count; i++) { + if (ioreq->req.operation == BLKIF_OP_READ) { + segs[i].flags = GNTCOPY_dest_gref; + segs[i].dest.foreign.ref = ioreq->refs[i]; + segs[i].dest.foreign.domid = ioreq->domids[i]; + segs[i].dest.foreign.offset = ioreq->req.seg[i].first_sect * file_blk; + segs[i].source.virt = ioreq->v.iov[i].iov_base; + } else { + segs[i].flags = GNTCOPY_source_gref; + segs[i].source.foreign.ref = ioreq->refs[i]; + segs[i].source.foreign.domid = ioreq->domids[i]; + segs[i].source.foreign.offset = ioreq->req.seg[i].first_sect * file_blk; + segs[i].dest.virt = ioreq->v.iov[i].iov_base; + } + segs[i].len = (ioreq->req.seg[i].last_sect + - ioreq->req.seg[i].first_sect + 1) * file_blk; + } + + rc = xengnttab_grant_copy(gnt, count, segs); + + if (rc) { + xen_be_printf(&ioreq->blkdev->xendev, 0, + "failed to copy data %d\n", rc); + ioreq->aio_errors++; + return -1; + } + + for (i = 0; i < count; i++) { + if (segs[i].status != GNTST_okay) { + xen_be_printf(&ioreq->blkdev->xendev, 3, + "failed to copy data %d for gref %d, domid %d\n", + segs[i].status, ioreq->refs[i], ioreq->domids[i]); + ioreq->aio_errors++; + rc = -1; + } + } + + return rc; +} +#else +static void ioreq_free_copy_buffers(struct ioreq *ioreq) +{ + abort(); +} + +static int ioreq_init_copy_buffers(struct ioreq *ioreq) +{ + abort(); +} + +static int ioreq_grant_copy(struct ioreq *ioreq) +{ + abort(); +} +#endif + static int ioreq_runio_qemu_aio(struct ioreq *ioreq); static void qemu_aio_complete(void *opaque, int ret) @@ -511,8 +614,31 @@ static void qemu_aio_complete(void *opaque, int ret) return; } + if (ioreq->blkdev->feature_grant_copy) { + switch (ioreq->req.operation) { + case BLKIF_OP_READ: + /* in case of failure ioreq->aio_errors is increased */ + if (ret == 0) { + ioreq_grant_copy(ioreq); + } + ioreq_free_copy_buffers(ioreq); + break; + case BLKIF_OP_WRITE: + case BLKIF_OP_FLUSH_DISKCACHE: + if (!ioreq->req.nr_segments) { + break; + } + ioreq_free_copy_buffers(ioreq); + break; + default: + break; + } + } + ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY; - ioreq_unmap(ioreq); + if (!ioreq->blkdev->feature_grant_copy) { + ioreq_unmap(ioreq); + } ioreq_finish(ioreq); switch (ioreq->req.operation) { case BLKIF_OP_WRITE: @@ -538,8 +664,18 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) { struct XenBlkDev *blkdev = ioreq->blkdev; - if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) { - goto err_no_map; + if (ioreq->blkdev->feature_grant_copy) { + ioreq_init_copy_buffers(ioreq); + if (ioreq->req.nr_segments && (ioreq->req.operation == BLKIF_OP_WRITE || + ioreq->req.operation == BLKIF_OP_FLUSH_DISKCACHE) && + ioreq_grant_copy(ioreq)) { + ioreq_free_copy_buffers(ioreq); + goto err; + } + } else { + if (ioreq->req.nr_segments && ioreq_map(ioreq)) { + goto err; + } } ioreq->aio_inflight++; @@ -582,6 +718,9 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) } default: /* unknown operation (shouldn't happen -- parse catches this) */ + if (!ioreq->blkdev->feature_grant_copy) { + ioreq_unmap(ioreq); + } goto err; } @@ -590,8 +729,6 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) return 0; err: - ioreq_unmap(ioreq); -err_no_map: ioreq_finish(ioreq); ioreq->status = BLKIF_RSP_ERROR; return -1; @@ -1034,6 +1171,12 @@ static int blk_connect(struct XenDevice *xendev) xen_be_bind_evtchn(&blkdev->xendev); + blkdev->feature_grant_copy = + (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); + + xen_be_printf(&blkdev->xendev, 3, "grant copy operation %s\n", + blkdev->feature_grant_copy ? "enabled" : "disabled"); + 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, |