Alex / Joerg,
On 1/24/18 5:04 AM, Alex Williamson wrote:
@@ -648,12 +685,40 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
return i > npage ? npage : (i > 0 ? i : -EINVAL);
}
+static size_t try_unmap_unpin_fast(struct vfio_domain *domain, dma_addr_t iova,
+ size_t len, phys_addr_t phys,
+ struct list_head *unmapped_regions)
+{
+ struct vfio_regions *entry;
+ size_t unmapped;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ unmapped = iommu_unmap_fast(domain->domain, iova, len);
+ if (WARN_ON(!unmapped)) {
+ kfree(entry);
+ return -EINVAL;
+ }
Not sure about the handling of this, the zero check is just a
consistency validation. If there's nothing mapped where we think there
should be something mapped, we warn and throw out the whole vfio_dma.
After this patch, such an error gets warned twice, which doesn't
really seem to be an improvement.
Since iommu_unmap() and iommu_unmap_fast() can return errors, instead of just zero check,
we should also check for errors, warn, and bail out the whole vfio_dma.
Thanks,
Suravee
