Re: [PATCH v2 12/26] iommu/amd: Add per-VM private IPA alloc/map helpers

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, May 28, 2026 at 05:17:24AM +0000, Suravee Suthikulpanit wrote:
> +static int __maybe_unused alloc_private_vm_region(struct amd_iommu *iommu, u64 **entry,
> +						 u64 base, size_t size, u16 gid)
> +{
> +	int ret;
> +	u64 addr = base + (gid * size);
> +	int nid = iommu && iommu->dev ? dev_to_node(&iommu->dev->dev) : NUMA_NO_NODE;
> +
> +	*entry = (void *)iommu_alloc_pages_node_sz(nid, GFP_KERNEL | __GFP_ZERO, size);
> +	if (!*entry)
> +		return -ENOMEM;

No cast

> +	ret = set_memory_uc((unsigned long)*entry, size >> PAGE_SHIFT);
> +	if (ret)
> +		goto err_out;
> +
> +	pr_debug("%s: entry=%#llx(%#llx), addr=%#llx, size=%#lx\n", __func__,
> +		 (unsigned long  long)*entry, iommu_virt_to_phys(*entry), addr, size);
> +
> +	ret = iommu_map(&iommu->viommu_pdom->domain, addr,
> +			iommu_virt_to_phys(*entry), size,
> +			IOMMU_PROT_IR | IOMMU_PROT_IW, GFP_KERNEL);
> +	if (ret)
> +		goto cleanup_mem_attr;
> +
> +	return amd_iommu_flush_private_vm_region(iommu, iommu->viommu_pdom, addr, size);
> +cleanup_mem_attr:
> +	set_memory_wb((unsigned long)*entry, size >> PAGE_SHIFT);
> +err_out:
> +	iommu_free_pages(*entry);
> +	*entry = NULL;
> +	return ret;
> +}

This all seems duplicated from the prior patch, you should try to make
one helper that does this alloc and map sequence.

> +static void __maybe_unused free_private_vm_region(struct amd_iommu *iommu, u64 **entry,
> +						  u64 base, size_t size, u16 gid)
> +{
> +	size_t unmapped;
> +	u64 addr = base + (gid * size);
> +
> +	pr_debug("%s: entry=%#llx(%#llx), base=%#llx, addr=%#llx, size=%#lx\n",
> +		 __func__, (unsigned long  long)*entry,
> +		 iommu_virt_to_phys(*entry), base, addr, size);
> +
> +	if (!iommu || !iommu->viommu_pdom)
> +		return;
> +
> +	unmapped = iommu_unmap(&iommu->viommu_pdom->domain, addr, size);
> +	if (unmapped != size)
> +		pr_warn("%s: unmapped %#zx of %#lx at %#llx\n", __func__, unmapped, size, addr);

No flush? Or does the gather work for the special domain?

Jason