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Date:   Mon, 4 Dec 2023 14:34:10 -0400
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Yan Zhao <yan.y.zhao@intel.com>
Cc:     iommu@lists.linux.dev, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, alex.williamson@redhat.com,
        pbonzini@redhat.com, seanjc@google.com, joro@8bytes.org,
        will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com,
        baolu.lu@linux.intel.com, dwmw2@infradead.org, yi.l.liu@intel.com
Subject: Re: [RFC PATCH 14/42] iommufd: Enable KVM HW page table object to be
 proxy between KVM and IOMMU
Message-ID: <20231204183410.GM1493156@nvidia.com>
References: <20231202091211.13376-1-yan.y.zhao@intel.com>
 <20231202092216.14278-1-yan.y.zhao@intel.com>
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On Sat, Dec 02, 2023 at 05:22:16PM +0800, Yan Zhao wrote:
> +config IOMMUFD_KVM_HWPT
> +	bool "Supports KVM managed HW page tables"
> +	default n
> +	help
> +	  Selecting this option will allow IOMMUFD to create IOMMU stage 2
> +	  page tables whose paging structure and mappings are managed by
> +	  KVM MMU. IOMMUFD serves as proxy between KVM and IOMMU driver to
> +	  allow IOMMU driver to get paging structure meta data and cache
> +	  invalidate notifications from KVM.

I'm not sure we need a user selectable kconfig for this..

Just turn it on if we have kvm turned on an iommu driver implements it

Jason