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
