Re: [PATCH v6 3/8] iommu/vt-d: Add helper for nested domain allocation

[Baolu Lu <baolu.lu@linux.intel.com>]

On 2023/10/20 17:32, Yi Liu wrote:
> From: Lu Baolu <baolu.lu@linux.intel.com>
> 
> This adds helper for accepting user parameters and allocate a nested
> domain.
> 
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
>   drivers/iommu/intel/Makefile |  2 +-
>   drivers/iommu/intel/iommu.h  |  2 ++
>   drivers/iommu/intel/nested.c | 55 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 58 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/iommu/intel/nested.c
> 
> diff --git a/drivers/iommu/intel/Makefile b/drivers/iommu/intel/Makefile
> index 7af3b8a4f2a0..5dabf081a779 100644
> --- a/drivers/iommu/intel/Makefile
> +++ b/drivers/iommu/intel/Makefile
> @@ -1,6 +1,6 @@
>   # SPDX-License-Identifier: GPL-2.0
>   obj-$(CONFIG_DMAR_TABLE) += dmar.o
> -obj-$(CONFIG_INTEL_IOMMU) += iommu.o pasid.o
> +obj-$(CONFIG_INTEL_IOMMU) += iommu.o pasid.o nested.o
>   obj-$(CONFIG_DMAR_TABLE) += trace.o cap_audit.o
>   obj-$(CONFIG_DMAR_PERF) += perf.o
>   obj-$(CONFIG_INTEL_IOMMU_DEBUGFS) += debugfs.o
> diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
> index a91077a063ee..ff55184456dd 100644
> --- a/drivers/iommu/intel/iommu.h
> +++ b/drivers/iommu/intel/iommu.h
> @@ -866,6 +866,8 @@ void *alloc_pgtable_page(int node, gfp_t gfp);
>   void free_pgtable_page(void *vaddr);
>   void iommu_flush_write_buffer(struct intel_iommu *iommu);
>   struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn);
> +struct iommu_domain *intel_nested_domain_alloc(struct iommu_domain *s2_domain,
> +					       const struct iommu_user_data *user_data);
>   
>   #ifdef CONFIG_INTEL_IOMMU_SVM
>   void intel_svm_check(struct intel_iommu *iommu);
> diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
> new file mode 100644
> index 000000000000..5a2920a98e47
> --- /dev/null
> +++ b/drivers/iommu/intel/nested.c
> @@ -0,0 +1,55 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * nested.c - nested mode translation support
> + *
> + * Copyright (C) 2023 Intel Corporation
> + *
> + * Author: Lu Baolu <baolu.lu@linux.intel.com>
> + *         Jacob Pan <jacob.jun.pan@linux.intel.com>
> + *         Yi Liu <yi.l.liu@intel.com>
> + */
> +
> +#define pr_fmt(fmt)	"DMAR: " fmt
> +
> +#include <linux/iommu.h>
> +
> +#include "iommu.h"
> +
> +static void intel_nested_domain_free(struct iommu_domain *domain)
> +{
> +	kfree(to_dmar_domain(domain));
> +}
> +
> +static const struct iommu_domain_ops intel_nested_domain_ops = {
> +	.free			= intel_nested_domain_free,
> +};
> +
> +struct iommu_domain *intel_nested_domain_alloc(struct iommu_domain *s2_domain,
> +					       const struct iommu_user_data *user_data)
> +{
> +	struct iommu_hwpt_vtd_s1 vtd;
> +	struct dmar_domain *domain;
> +	int ret;
> +
> +	ret = iommu_copy_struct_from_user(&vtd, user_data,
> +					  IOMMU_HWPT_DATA_VTD_S1, __reserved);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	domain = kzalloc(sizeof(*domain), GFP_KERNEL_ACCOUNT);
> +	if (!domain)
> +		return NULL;

	return ERR_PTR(-ENOMEM);
?

> +
> +	domain->use_first_level = true;
> +	domain->s2_domain = to_dmar_domain(s2_domain);
> +	domain->s1_pgtbl = vtd.pgtbl_addr;
> +	domain->s1_cfg = vtd;
> +	domain->domain.ops = &intel_nested_domain_ops;
> +	domain->domain.type = IOMMU_DOMAIN_NESTED;
> +	INIT_LIST_HEAD(&domain->devices);
> +	INIT_LIST_HEAD(&domain->dev_pasids);
> +	spin_lock_init(&domain->lock);
> +	xa_init(&domain->iommu_array);
> +
> +	return &domain->domain;
> +}

Best regards,
baolu