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Commit 7a30423a authored by Joerg Roedel's avatar Joerg Roedel
Browse files

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: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 6f820bb9

drivers/vfio/vfio_iommu_type1.c

+2 −31
Original line number Diff line number Diff line
@@ -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))

		if (ret)

			goto unwind;

		}



		cond_resched();

	}