From e5a6f60206f58a35601b2bada6ec4fedf5d2ace7 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Tue, 22 Apr 2014 14:14:19 +0100 Subject: [PATCH] xen/common: grant-table: only call IOMMU if paging mode translate is disabled From Xen point of view, ARM guests are PV guest with paging auto translate enabled. When IOMMU support will be added for ARM, mapping grant ref will always crash Xen due to the BUG_ON in __gnttab_map_grant_ref. On x86: - PV guests always have paging mode translate disabled - PVH and HVM guests have always paging mode translate enabled It means that we can safely replace the check that the domain is a PV guests by checking if the guest has paging mode translate enabled. Signed-off-by: Julien Grall Reviewed-by: Jan Beulich Acked-by: Ian Campbell Cc: Keir Fraser --- xen/common/grant_table.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c index 107b000fd8..778bdb7672 100644 --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -721,12 +721,10 @@ __gnttab_map_grant_ref( double_gt_lock(lgt, rgt); - if ( is_pv_domain(ld) && need_iommu(ld) ) + if ( !paging_mode_translate(ld) && need_iommu(ld) ) { unsigned int wrc, rdc; int err = 0; - /* Shouldn't happen, because you can't use iommu in a HVM domain. */ - BUG_ON(paging_mode_translate(ld)); /* We're not translated, so we know that gmfns and mfns are the same things, so the IOMMU entry is always 1-to-1. */ mapcount(lgt, rd, frame, &wrc, &rdc); @@ -931,11 +929,10 @@ __gnttab_unmap_common( act->pin -= GNTPIN_hstw_inc; } - if ( is_pv_domain(ld) && need_iommu(ld) ) + if ( !paging_mode_translate(ld) && need_iommu(ld) ) { unsigned int wrc, rdc; int err = 0; - BUG_ON(paging_mode_translate(ld)); mapcount(lgt, rd, op->frame, &wrc, &rdc); if ( (wrc + rdc) == 0 ) err = iommu_unmap_page(ld, op->frame); -- 2.30.2