RE: [PATCH v6 10/25] iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl

From: Nicolin Chen nicolinc@nvidia.com Sent: Saturday, June 14, 2025 3:15 PM

• offset =

• cmd->nesting_parent_iova - PAGE_ALIGN(cmd-
  

...

nesting_parent_iova);

• max_npages = DIV_ROUND_UP(offset + cmd->length, PAGE_SIZE);
• /*

• * FIXME allocation may fail when sizeof(*pages) * max_npages is
  

• * larger than PAGE_SIZE. This might need a new API returning a
  

• * bio_vec or something more efficient.
  

• */
  

• pages = kcalloc(max_npages, sizeof(*pages), GFP_KERNEL);
• if (!pages)

• return ERR_PTR(-ENOMEM);
  

any allocation may fail... can you elaborate more here? How does PAGE_SIZE become a boundary?