From 7a30423a95a11ac474115f07cba7f6071f75ff81 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 9 Nov 2018 12:07:12 +0100 Subject: [PATCH] vfio/type1: Remove map_try_harder() code path The AMD IOMMU driver can now map a huge-page where smaller mappings existed before, so this code-path is no longer triggered. Acked-by: Alex Williamson Signed-off-by: Joerg Roedel --- drivers/vfio/vfio_iommu_type1.c | 33 ++------------------------------- 1 file changed, 2 insertions(+), 31 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index d9fd3188615d..7651cfb14836 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -978,32 +978,6 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, return ret; } -/* - * Turns out AMD IOMMU has a page table bug where it won't map large pages - * to a region that previously mapped smaller pages. This should be fixed - * soon, so this is just a temporary workaround to break mappings down into - * PAGE_SIZE. Better to map smaller pages than nothing. - */ -static int map_try_harder(struct vfio_domain *domain, dma_addr_t iova, - unsigned long pfn, long npage, int prot) -{ - long i; - int ret = 0; - - for (i = 0; i < npage; i++, pfn++, iova += PAGE_SIZE) { - ret = iommu_map(domain->domain, iova, - (phys_addr_t)pfn << PAGE_SHIFT, - PAGE_SIZE, prot | domain->prot); - if (ret) - break; - } - - for (; i < npage && i > 0; i--, iova -= PAGE_SIZE) - iommu_unmap(domain->domain, iova, PAGE_SIZE); - - return ret; -} - static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova, unsigned long pfn, long npage, int prot) { @@ -1013,11 +987,8 @@ static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova, list_for_each_entry(d, &iommu->domain_list, next) { ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT, npage << PAGE_SHIFT, prot | d->prot); - if (ret) { - if (ret != -EBUSY || - map_try_harder(d, iova, pfn, npage, prot)) - goto unwind; - } + if (ret) + goto unwind; cond_resched(); }