From 2212fc2acf3f6ee690ea36506fb882a19d1bfcab Mon Sep 17 00:00:00 2001 From: Jon Pan-Doh Date: Wed, 26 Apr 2023 13:32:56 -0700 Subject: [PATCH] iommu/amd: Fix domain flush size when syncing iotlb When running on an AMD vIOMMU, we observed multiple invalidations (of decreasing power of 2 aligned sizes) when unmapping a single page. Domain flush takes gather bounds (end-start) as size param. However, gather->end is defined as the last inclusive address (start + size - 1). This leads to an off by 1 error. With this patch, verified that 1 invalidation occurs when unmapping a single page. Fixes: a270be1b3fdf ("iommu/amd: Use only natural aligned flushes in a VM") Cc: stable@vger.kernel.org # >= 5.15 Signed-off-by: Jon Pan-Doh Tested-by: Sudheer Dantuluri Suggested-by: Gary Zibrat Reviewed-by: Vasant Hegde Acked-by: Nadav Amit Link: https://lore.kernel.org/r/20230426203256.237116-1-pandoh@google.com Signed-off-by: Joerg Roedel --- drivers/iommu/amd/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 3797e35df035..0f3ac4b489d6 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2398,7 +2398,7 @@ static void amd_iommu_iotlb_sync(struct iommu_domain *domain, unsigned long flags; spin_lock_irqsave(&dom->lock, flags); - domain_flush_pages(dom, gather->start, gather->end - gather->start, 1); + domain_flush_pages(dom, gather->start, gather->end - gather->start + 1, 1); amd_iommu_domain_flush_complete(dom); spin_unlock_irqrestore(&dom->lock, flags); }