From d59f532480f5231bf62615a9287e05b78225fb05 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 19 Sep 2018 15:42:33 +0200 Subject: [PATCH] xen: issue warning message when out of grant maptrack entries When a driver domain (e.g. dom0) is running out of maptrack entries it can't map any more foreign domain pages. Instead of silently stalling the affected domUs issue a rate limited warning in this case in order to make it easier to detect that situation. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky --- drivers/xen/grant-table.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 7bafa703a992..84575baceebc 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -1040,18 +1040,33 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, return ret; for (i = 0; i < count; i++) { - /* Retry eagain maps */ - if (map_ops[i].status == GNTST_eagain) - gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, - &map_ops[i].status, __func__); - - if (map_ops[i].status == GNTST_okay) { + switch (map_ops[i].status) { + case GNTST_okay: + { struct xen_page_foreign *foreign; SetPageForeign(pages[i]); foreign = xen_page_foreign(pages[i]); foreign->domid = map_ops[i].dom; foreign->gref = map_ops[i].ref; + break; + } + + case GNTST_no_device_space: + pr_warn_ratelimited("maptrack limit reached, can't map all guest pages\n"); + break; + + case GNTST_eagain: + /* Retry eagain maps */ + gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, + map_ops + i, + &map_ops[i].status, __func__); + /* Test status in next loop iteration. */ + i--; + break; + + default: + break; } }