[Xen-devel] [RFC for-4.5 07/12] xen/passthrough: iommu: Don't need to map dom0 page when the PT is shared

[Julien Grall <julien.grall@xxxxxxxxxx>]

Currently iommu_init_dom0 is browsing the page list and call map_page callback
on each page.

On both AMD and VTD drivers, the function will directly return if the page
table is shared with the processor. So Xen can safely avoid to run through
the page list.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Cc: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/drivers/passthrough/iommu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 26a5d91..0a26956 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -157,7 +157,7 @@ void __init iommu_dom0_init(struct domain *d)
 
     register_keyhandler('o', &iommu_p2m_table);
     d->need_iommu = !!iommu_dom0_strict;
-    if ( need_iommu(d) )
+    if ( need_iommu(d) && !iommu_use_hap_pt(d) )
     {
         struct page_info *page;
         unsigned int i = 0;
-- 
1.7.10.4


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