This patch fixes two issues with persistent grants and the disk PV backend (Qdisk):
- Don't use batch mappings when using persistent grants, doing so prevents unmapping single grants (the whole area has to be unmapped at once). - Unmap persistent grants before switching to the closed state, so the frontend can also free them. Signed-off-by: Roger Pau Monné <roger....@citrix.com> Reported-and-Tested-by: George Dunlap <george.dun...@eu.citrix.com> Cc: Stefano Stabellini <stefano.stabell...@eu.citrix.com> Cc: Kevin Wolf <kw...@redhat.com> Cc: Stefan Hajnoczi <stefa...@redhat.com> Cc: George Dunlap <george.dun...@eu.citrix.com> --- hw/block/xen_disk.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 231e9a7..1300c0a 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -43,8 +43,6 @@ /* ------------------------------------------------------------- */ -static int batch_maps = 0; - static int max_requests = 32; /* ------------------------------------------------------------- */ @@ -105,6 +103,7 @@ struct XenBlkDev { blkif_back_rings_t rings; int more_work; int cnt_map; + bool batch_maps; /* request lists */ QLIST_HEAD(inflight_head, ioreq) inflight; @@ -309,7 +308,7 @@ static void ioreq_unmap(struct ioreq *ioreq) if (ioreq->num_unmap == 0 || ioreq->mapped == 0) { return; } - if (batch_maps) { + if (ioreq->blkdev->batch_maps) { if (!ioreq->pages) { return; } @@ -386,7 +385,7 @@ static int ioreq_map(struct ioreq *ioreq) new_maps = ioreq->v.niov; } - if (batch_maps && new_maps) { + if (ioreq->blkdev->batch_maps && new_maps) { ioreq->pages = xc_gnttab_map_grant_refs (gnt, new_maps, domids, refs, ioreq->prot); if (ioreq->pages == NULL) { @@ -433,7 +432,7 @@ static int ioreq_map(struct ioreq *ioreq) */ grant = g_malloc0(sizeof(*grant)); new_maps--; - if (batch_maps) { + if (ioreq->blkdev->batch_maps) { grant->page = ioreq->pages + (new_maps) * XC_PAGE_SIZE; } else { grant->page = ioreq->page[new_maps]; @@ -718,7 +717,9 @@ static void blk_alloc(struct XenDevice *xendev) QLIST_INIT(&blkdev->freelist); blkdev->bh = qemu_bh_new(blk_bh, blkdev); if (xen_mode != XEN_EMULATE) { - batch_maps = 1; + blkdev->batch_maps = TRUE; + } else { + blkdev->batch_maps = FALSE; } if (xc_gnttab_set_max_grants(xendev->gnttabdev, MAX_GRANTS(max_requests, BLKIF_MAX_SEGMENTS_PER_REQUEST)) < 0) { @@ -923,6 +924,13 @@ static int blk_connect(struct XenDevice *xendev) } else { blkdev->feature_persistent = !!pers; } + if (blkdev->feature_persistent) { + /* + * Disable batch maps, since that would prevent unmapping + * single persistent grants. + */ + blkdev->batch_maps = FALSE; + } blkdev->protocol = BLKIF_PROTOCOL_NATIVE; if (blkdev->xendev.protocol) { @@ -1000,6 +1008,16 @@ static void blk_disconnect(struct XenDevice *xendev) blkdev->cnt_map--; blkdev->sring = NULL; } + + /* + * Unmap persistent grants before switching to the closed state + * so the frontend can free them. + */ + if (blkdev->feature_persistent) { + g_tree_destroy(blkdev->persistent_gnts); + assert(blkdev->persistent_gnt_count == 0); + blkdev->feature_persistent = FALSE; + } } static int blk_free(struct XenDevice *xendev) @@ -1011,11 +1029,6 @@ static int blk_free(struct XenDevice *xendev) blk_disconnect(xendev); } - /* Free persistent grants */ - if (blkdev->feature_persistent) { - g_tree_destroy(blkdev->persistent_gnts); - } - while (!QLIST_EMPTY(&blkdev->freelist)) { ioreq = QLIST_FIRST(&blkdev->freelist); QLIST_REMOVE(ioreq, list); -- 1.9.3 (Apple Git-50) _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel