Re: [RFC 6/7] iommu/vt-d: convert the intel iommu driver to the dma-iommu ops api

From: Lu Baolu <baolu.lu@linux.intel.com>
To: Tom Murphy <tmurphy@arista.com>, iommu@lists.linux-foundation.org
Cc: Heiko Stuebner <heiko@sntech.de>,
	kvm@vger.kernel.org, Will Deacon <will.deacon@arm.com>,
	David Brown <david.brown@linaro.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	linux-rockchip@lists.infradead.org, Kukjin Kim <kgene@kernel.org>,
	Gerald Schaefer <gerald.schaefer@de.ibm.com>,
	Andy Gross <andy.gross@linaro.org>,
	linux-tegra@vger.kernel.org, Marc Zyngier <marc.zyngier@arm.com>,
	linux-arm-msm@vger.kernel.org,
	Alex Williamson <alex.williamson@redhat.com>,
	linux-mediatek@lists.infradead.org,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-arm-kernel@lists.infradead.org,
	Robin Murphy <robin.murphy@arm.com>,
	linux-kernel@vger.kernel.org, murphyt7@tcd.ie,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: [RFC 6/7] iommu/vt-d: convert the intel iommu driver to the dma-iommu ops api
Date: Sun, 5 May 2019 10:37:32 +0800	[thread overview]
Message-ID: <602b77a2-9c68-ad14-b64f-904a7ff27a15@linux.intel.com> (raw)
In-Reply-To: <20190504132327.27041-7-tmurphy@arista.com>

Hi,

On 5/4/19 9:23 PM, Tom Murphy wrote:
> static int intel_iommu_add_device(struct device *dev)
>   {
> +	struct dmar_domain *dmar_domain;
> +	struct iommu_domain *domain;
>   	struct intel_iommu *iommu;
>   	struct iommu_group *group;
> -	struct iommu_domain *domain;
> +	dma_addr_t base;
>   	u8 bus, devfn;
>   
>   	iommu = device_to_iommu(dev, &bus, &devfn);
> @@ -4871,9 +4514,12 @@ static int intel_iommu_add_device(struct device *dev)
>   	if (IS_ERR(group))
>   		return PTR_ERR(group);
>   
> +	base = IOVA_START_PFN << VTD_PAGE_SHIFT;
>   	domain = iommu_get_domain_for_dev(dev);
> +	dmar_domain = to_dmar_domain(domain);
>   	if (domain->type == IOMMU_DOMAIN_DMA)
> -		dev->dma_ops = &intel_dma_ops;
> +		iommu_setup_dma_ops(dev, base,
> +				__DOMAIN_MAX_ADDR(dmar_domain->gaw) - base);

I didn't find the implementation of iommu_setup_dma_ops() in this
series. Will the iova resource be initialized in this function?

If so, will this block iommu_group_create_direct_mappings() which
reserves and maps the reserved iova ranges.

>   
>   	iommu_group_put(group);
>   	return 0;
> @@ -5002,19 +4648,6 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sd
>   	return ret;
>   }
>   
> -static void intel_iommu_apply_resv_region(struct device *dev,
> -					  struct iommu_domain *domain,
> -					  struct iommu_resv_region *region)
> -{
> -	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> -	unsigned long start, end;
> -
> -	start = IOVA_PFN(region->start);
> -	end   = IOVA_PFN(region->start + region->length - 1);
> -
> -	WARN_ON_ONCE(!reserve_iova(&dmar_domain->iovad, start, end));
> -}
> -
>   struct intel_iommu *intel_svm_device_to_iommu(struct device *dev)
>   {
>   	struct intel_iommu *iommu;
> @@ -5050,13 +4683,13 @@ const struct iommu_ops intel_iommu_ops = {
>   	.detach_dev		= intel_iommu_detach_device,
>   	.map			= intel_iommu_map,
>   	.unmap			= intel_iommu_unmap,
> +	.flush_iotlb_all	= iommu_flush_iova,
>   	.flush_iotlb_range	= intel_iommu_flush_iotlb_range,
>   	.iova_to_phys		= intel_iommu_iova_to_phys,
>   	.add_device		= intel_iommu_add_device,
>   	.remove_device		= intel_iommu_remove_device,
>   	.get_resv_regions	= intel_iommu_get_resv_regions,
>   	.put_resv_regions	= intel_iommu_put_resv_regions,
> -	.apply_resv_region	= intel_iommu_apply_resv_region,

With this removed, how will iommu_group_create_direct_mappings() work?

Best regards,
Lu Baolu
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