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Date:   Tue, 17 Apr 2018 13:10:45 -0600
From:   Alex Williamson <alex.williamson@redhat.com>
To:     Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc:     iommu@lists.linux-foundation.org,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        David Woodhouse <dwmw2@infradead.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jean-Philippe Brucker <jean-philippe.brucker@arm.com>,
        Rafael Wysocki <rafael.j.wysocki@intel.com>,
        "Liu, Yi L" <yi.l.liu@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>,
        Raj Ashok <ashok.raj@intel.com>,
        Jean Delvare <khali@linux-fr.org>,
        "Christoph Hellwig" <hch@infradead.org>,
        "Lu Baolu" <baolu.lu@linux.intel.com>,
        Yi L <yi.l.liu@linux.intel.com>
Subject: Re: [PATCH v4 09/22] iommu/vt-d: add svm/sva invalidate function
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In-Reply-To: <1523915351-54415-10-git-send-email-jacob.jun.pan@linux.intel.com>
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        <1523915351-54415-10-git-send-email-jacob.jun.pan@linux.intel.com>
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On Mon, 16 Apr 2018 14:48:58 -0700
Jacob Pan <jacob.jun.pan@linux.intel.com> wrote:

> When Shared Virtual Address (SVA) is enabled for a guest OS via
> vIOMMU, we need to provide invalidation support at IOMMU API and driver
> level. This patch adds Intel VT-d specific function to implement
> iommu passdown invalidate API for shared virtual address.
> 
> The use case is for supporting caching structure invalidation
> of assigned SVM capable devices. Emulated IOMMU exposes queue
> invalidation capability and passes down all descriptors from the guest
> to the physical IOMMU.
> 
> The assumption is that guest to host device ID mapping should be
> resolved prior to calling IOMMU driver. Based on the device handle,
> host IOMMU driver can replace certain fields before submit to the
> invalidation queue.
> 
> Signed-off-by: Liu, Yi L <yi.l.liu@linux.intel.com>
> Signed-off-by: Ashok Raj <ashok.raj@intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>  drivers/iommu/intel-iommu.c | 170 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 170 insertions(+)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index cae4042..c765448 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -4973,6 +4973,175 @@ static void intel_iommu_detach_device(struct iommu_domain *domain,
>  	dmar_remove_one_dev_info(to_dmar_domain(domain), dev);
>  }
>  
> +/*
> + * 3D array for converting IOMMU generic type-granularity to VT-d granularity
> + * X indexed by enum iommu_inv_type
> + * Y indicates request without and with PASID
> + * Z indexed by enum iommu_inv_granularity
> + *
> + * For an example, if we want to find the VT-d granularity encoding for IOTLB
> + * type, DMA request with PASID, and page selective. The look up indices are:
> + * [1][1][8], where
> + * 1: IOMMU_INV_TYPE_TLB
> + * 1: with PASID
> + * 8: IOMMU_INV_GRANU_PAGE_PASID
> + *
> + * Granu_map array indicates validity of the table. 1: valid, 0: invalid
> + *
> + */
> +const static int inv_type_granu_map[IOMMU_INV_NR_TYPE][2][IOMMU_INV_NR_GRANU] = {
> +	/* extended dev IOTLBs, for dev-IOTLB, only global is valid,
> +	   for dev-EXIOTLB, two valid granu */
> +	{
> +		{1},
> +		{0, 0, 0, 0, 1, 1, 0, 0, 0}
> +	},
> +	/* IOTLB and EIOTLB */
> +	{
> +		{1, 1, 0, 1, 0, 0, 0, 0, 0},
> +		{0, 0, 0, 0, 1, 0, 1, 1, 1}
> +	},
> +	/* PASID cache */
> +	{
> +		{0},
> +		{0, 0, 0, 0, 1, 1, 0, 0, 0}
> +	},
> +	/* context cache */
> +	{
> +		{1, 1, 1}
> +	}
> +};
> +
> +const static u64 inv_type_granu_table[IOMMU_INV_NR_TYPE][2][IOMMU_INV_NR_GRANU] = {
> +	/* extended dev IOTLBs, only global is valid */
> +	{
> +		{QI_DEV_IOTLB_GRAN_ALL},
> +		{0, 0, 0, 0, QI_DEV_IOTLB_GRAN_ALL, QI_DEV_IOTLB_GRAN_PASID_SEL, 0, 0, 0}
> +	},
> +	/* IOTLB and EIOTLB */
> +	{
> +		{DMA_TLB_GLOBAL_FLUSH, DMA_TLB_DSI_FLUSH, 0, DMA_TLB_PSI_FLUSH},
> +		{0, 0, 0, 0, QI_GRAN_ALL_ALL, 0, QI_GRAN_NONG_ALL, QI_GRAN_NONG_PASID, QI_GRAN_PSI_PASID}
> +	},
> +	/* PASID cache */
> +	{
> +		{0},
> +		{0, 0, 0, 0, QI_PC_ALL_PASIDS, QI_PC_PASID_SEL}
> +	},
> +	/* context cache */
> +	{
> +		{DMA_CCMD_GLOBAL_INVL, DMA_CCMD_DOMAIN_INVL, DMA_CCMD_DEVICE_INVL}
> +	}
> +};
> +
> +static inline int to_vtd_granularity(int type, int granu, int with_pasid, u64 *vtd_granu)
> +{
> +	if (type >= IOMMU_INV_NR_TYPE || granu >= IOMMU_INV_NR_GRANU || with_pasid > 1)
> +		return -EINVAL;
> +
> +	if (inv_type_granu_map[type][with_pasid][granu] == 0)
> +		return -EINVAL;
> +
> +	*vtd_granu = inv_type_granu_table[type][with_pasid][granu];
> +
> +	return 0;
> +}
> +
> +static int intel_iommu_sva_invalidate(struct iommu_domain *domain,
> +		struct device *dev, struct tlb_invalidate_info *inv_info)

inv_info->hdr.version is never checked, why do we have these if they're
not used?

> +{
> +	struct intel_iommu *iommu;
> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> +	struct device_domain_info *info;
> +	u16 did, sid;
> +	u8 bus, devfn;
> +	int ret = 0;
> +	u64 granu;
> +	unsigned long flags;
> +
> +	if (!inv_info || !dmar_domain)
> +		return -EINVAL;
> +
> +	iommu = device_to_iommu(dev, &bus, &devfn);
> +	if (!iommu)
> +		return -ENODEV;
> +
> +	if (!dev || !dev_is_pci(dev))
> +		return -ENODEV;
> +
> +	did = dmar_domain->iommu_did[iommu->seq_id];
> +	sid = PCI_DEVID(bus, devfn);
> +	ret = to_vtd_granularity(inv_info->hdr.type, inv_info->granularity,
> +				!!(inv_info->flags & IOMMU_INVALIDATE_PASID_TAGGED), &granu);
> +	if (ret) {
> +		pr_err("Invalid range type %d, granu %d\n", inv_info->hdr.type,
> +			inv_info->granularity);
> +		return ret;
> +	}
> +
> +	spin_lock(&iommu->lock);
> +	spin_lock_irqsave(&device_domain_lock, flags);
> +
> +	switch (inv_info->hdr.type) {
> +	case IOMMU_INV_TYPE_CONTEXT:
> +		iommu->flush.flush_context(iommu, did, sid,
> +					DMA_CCMD_MASK_NOBIT, granu);
> +		break;
> +	case IOMMU_INV_TYPE_TLB:
> +		/* We need to deal with two scenarios:
> +		 * - IOTLB for request w/o PASID
> +		 * - extended IOTLB for request with PASID.
> +		 */
> +		if (inv_info->size &&
> +			(inv_info->addr & ((1 << (VTD_PAGE_SHIFT + inv_info->size)) - 1))) {
> +			pr_err("Addr out of range, addr 0x%llx, size order %d\n",
> +				inv_info->addr, inv_info->size);
> +			ret = -ERANGE;
> +			goto out_unlock;
> +		}
> +
> +		if (inv_info->flags & IOMMU_INVALIDATE_PASID_TAGGED)
> +			qi_flush_eiotlb(iommu, did, mm_to_dma_pfn(inv_info->addr),
> +					inv_info->pasid,
> +					inv_info->size, granu,
> +					inv_info->flags & IOMMU_INVALIDATE_GLOBAL_PAGE);
> +		else
> +			qi_flush_iotlb(iommu, did, mm_to_dma_pfn(inv_info->addr),
> +				inv_info->size, granu);
> +		/**
> +		 * Always flush device IOTLB if ATS is enabled since guest
> +		 * vIOMMU exposes CM = 1, no device IOTLB flush will be passed
> +		 * down.
> +		 */
> +		info = iommu_support_dev_iotlb(dmar_domain, iommu, bus, devfn);
> +		if (info && info->ats_enabled) {
> +			if (inv_info->flags & IOMMU_INVALIDATE_PASID_TAGGED)
> +				qi_flush_dev_eiotlb(iommu, sid,
> +						inv_info->pasid, info->ats_qdep,
> +						inv_info->addr, inv_info->size,
> +						granu);
> +			else
> +				qi_flush_dev_iotlb(iommu, sid, info->pfsid,
> +						info->ats_qdep, inv_info->addr,
> +						inv_info->size);
> +		}
> +		break;
> +	case IOMMU_INV_TYPE_PASID:
> +		qi_flush_pasid(iommu, did, granu, inv_info->pasid);
> +
> +		break;
> +	default:
> +		dev_err(dev, "Unknown IOMMU invalidation type %d\n",
> +			inv_info->hdr.type);
> +		ret = -EINVAL;
> +	}


More verbose logging, is vfio just passing these through allowing them
to be user reachable?  Thanks,

Alex

> +out_unlock:
> +	spin_unlock(&iommu->lock);
> +	spin_unlock_irqrestore(&device_domain_lock, flags);
> +
> +	return ret;
> +}
> +
>  static int intel_iommu_map(struct iommu_domain *domain,
>  			   unsigned long iova, phys_addr_t hpa,
>  			   size_t size, int iommu_prot)
> @@ -5398,6 +5567,7 @@ const struct iommu_ops intel_iommu_ops = {
>  #ifdef CONFIG_INTEL_IOMMU_SVM
>  	.bind_pasid_table	= intel_iommu_bind_pasid_table,
>  	.unbind_pasid_table	= intel_iommu_unbind_pasid_table,
> +	.sva_invalidate		= intel_iommu_sva_invalidate,
>  #endif
>  	.map			= intel_iommu_map,
>  	.unmap			= intel_iommu_unmap,