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From: Jan Beulich <jbeulich@suse.com>
Subject: vtd: improve IOMMU TLB flush
Do not limit PSI flushes to order 0 pages, in order to avoid doing a
full TLB flush if the passed in page has an order greater than 0 and
is aligned. Should increase the performance of IOMMU TLB flushes when
dealing with page orders greater than 0.
This is part of XSA-321.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -570,13 +570,14 @@ static int __must_check iommu_flush_iotl
if ( iommu_domid == -1 )
continue;
- if ( page_count != 1 || dfn_eq(dfn, INVALID_DFN) )
+ if ( !page_count || (page_count & (page_count - 1)) ||
+ dfn_eq(dfn, INVALID_DFN) || !IS_ALIGNED(dfn_x(dfn), page_count) )
rc = iommu_flush_iotlb_dsi(iommu, iommu_domid,
0, flush_dev_iotlb);
else
rc = iommu_flush_iotlb_psi(iommu, iommu_domid,
dfn_to_daddr(dfn),
- PAGE_ORDER_4K,
+ get_order_from_pages(page_count),
!dma_old_pte_present,
flush_dev_iotlb);
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