Hi Jan,
> On 24 Sep 2021, at 10:43 am, Jan Beulich <jbeulich@suse.com> wrote:
>
> Generic code will use this information to determine what order values
> can legitimately be passed to the ->{,un}map_page() hooks. For now all
> ops structures simply get to announce 4k mappings (as base page size),
> and there is (and always has been) an assumption that this matches the
> CPU's MMU base page size (eventually we will want to permit IOMMUs with
> a base page size smaller than the CPU MMU's).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
Regards,
Rahul
>
> --- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
> +++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
> @@ -629,6 +629,7 @@ static void amd_dump_page_tables(struct
> }
>
> static const struct iommu_ops __initconstrel _iommu_ops = {
> + .page_sizes = PAGE_SIZE_4K,
> .init = amd_iommu_domain_init,
> .hwdom_init = amd_iommu_hwdom_init,
> .quarantine_init = amd_iommu_quarantine_init,
> --- a/xen/drivers/passthrough/arm/ipmmu-vmsa.c
> +++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
> @@ -1298,6 +1298,7 @@ static void ipmmu_iommu_domain_teardown(
>
> static const struct iommu_ops ipmmu_iommu_ops =
> {
> + .page_sizes = PAGE_SIZE_4K,
> .init = ipmmu_iommu_domain_init,
> .hwdom_init = ipmmu_iommu_hwdom_init,
> .teardown = ipmmu_iommu_domain_teardown,
> --- a/xen/drivers/passthrough/arm/smmu.c
> +++ b/xen/drivers/passthrough/arm/smmu.c
> @@ -2873,6 +2873,7 @@ static void arm_smmu_iommu_domain_teardo
> }
>
> static const struct iommu_ops arm_smmu_iommu_ops = {
> + .page_sizes = PAGE_SIZE_4K,
> .init = arm_smmu_iommu_domain_init,
> .hwdom_init = arm_smmu_iommu_hwdom_init,
> .add_device = arm_smmu_dt_add_device_generic,
> --- a/xen/drivers/passthrough/arm/smmu-v3.c
> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
> @@ -3426,7 +3426,8 @@ static void arm_smmu_iommu_xen_domain_te
> }
>
> static const struct iommu_ops arm_smmu_iommu_ops = {
> - .init = arm_smmu_iommu_xen_domain_init,
> + .page_sizes = PAGE_SIZE_4K,
> + .init = arm_smmu_iommu_xen_domain_init,
> .hwdom_init = arm_smmu_iommu_hwdom_init,
> .teardown = arm_smmu_iommu_xen_domain_teardown,
> .iotlb_flush = arm_smmu_iotlb_flush,
> --- a/xen/drivers/passthrough/iommu.c
> +++ b/xen/drivers/passthrough/iommu.c
> @@ -470,7 +470,17 @@ int __init iommu_setup(void)
>
> if ( iommu_enable )
> {
> + const struct iommu_ops *ops = NULL;
> +
> rc = iommu_hardware_setup();
> + if ( !rc )
> + ops = iommu_get_ops();
> + if ( ops && (ops->page_sizes & -ops->page_sizes) != PAGE_SIZE )
> + {
> + printk(XENLOG_ERR "IOMMU: page size mask %lx unsupported\n",
> + ops->page_sizes);
> + rc = ops->page_sizes ? -EPERM : -ENODATA;
> + }
> iommu_enabled = (rc == 0);
> }
>
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -2806,6 +2806,7 @@ static int __init intel_iommu_quarantine
> }
>
> static struct iommu_ops __initdata vtd_ops = {
> + .page_sizes = PAGE_SIZE_4K,
> .init = intel_iommu_domain_init,
> .hwdom_init = intel_iommu_hwdom_init,
> .quarantine_init = intel_iommu_quarantine_init,
> --- a/xen/include/xen/iommu.h
> +++ b/xen/include/xen/iommu.h
> @@ -231,6 +231,7 @@ struct page_info;
> typedef int iommu_grdm_t(xen_pfn_t start, xen_ulong_t nr, u32 id, void *ctxt);
>
> struct iommu_ops {
> + unsigned long page_sizes;
> int (*init)(struct domain *d);
> void (*hwdom_init)(struct domain *d);
> int (*quarantine_init)(struct domain *d);
>