From: Joerg Roedel <jroedel@xxxxxxx>
The AMD IOMMU driver can now map a huge-page where smaller
mappings existed before, so this code-path is no longer
triggered.
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
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();
}
--
2.17.1
