Mailing List Archive

[xen stable-4.13] vtd: improve IOMMU TLB flush
commit 1c7a98cab9101d8fedadd0bb0ccafc4498b37560
Author: Jan Beulich <jbeulich@suse.com>
AuthorDate: Tue Jul 7 15:01:57 2020 +0200
Commit: Jan Beulich <jbeulich@suse.com>
CommitDate: Tue Jul 7 15:01:57 2020 +0200

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>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: 5fe515a0fede07543f2a3b049167b1fd8b873caf
master date: 2020-07-07 14:37:46 +0200
---
xen/drivers/passthrough/vtd/iommu.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 26401c7e64..77cdc21837 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -570,13 +570,14 @@ static int __must_check iommu_flush_iotlb(struct domain *d, dfn_t dfn,
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);

--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.13