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From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	Ashok Raj <ashok.raj@intel.com>,
	Robin Murphy <robin.murphy@arm.com>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	Christoph Hellwig <hch@infradead.org>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>,
	Vinod Koul <vkoul@kernel.org>,
	Jacob jun Pan <jacob.jun.pan@intel.com>,
	Jason Gunthorpe <jgg@nvidia.com>, Will Deacon <will@kernel.org>
Subject: Re: [PATCH v7 08/10] iommu: Prepare IOMMU domain for IOPF
Date: Thu, 19 May 2022 17:40:21 +0100	[thread overview]
Message-ID: <YoZy9fnJlN/RIVY4@myrica> (raw)
In-Reply-To: <20220519072047.2996983-9-baolu.lu@linux.intel.com>

On Thu, May 19, 2022 at 03:20:45PM +0800, Lu Baolu wrote:
> This adds some mechanisms around the iommu_domain so that the I/O page
> fault handling framework could route a page fault to the domain and
> call the fault handler from it.
> 
> Add pointers to the page fault handler and its private data in struct
> iommu_domain. The fault handler will be called with the private data
> as a parameter once a page fault is routed to the domain. Any kernel
> component which owns an iommu domain could install handler and its
> private parameter so that the page fault could be further routed and
> handled.
> 
> This also prepares the SVA implementation to be the first consumer of
> the per-domain page fault handling model.
> 
> Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  include/linux/iommu.h         |  3 ++
>  drivers/iommu/io-pgfault.c    |  7 ++++
>  drivers/iommu/iommu-sva-lib.c | 65 +++++++++++++++++++++++++++++++++++
>  3 files changed, 75 insertions(+)
> 
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index e4ce2fe0e144..45f274b2640d 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -100,6 +100,9 @@ struct iommu_domain {
>  	void *handler_token;
>  	struct iommu_domain_geometry geometry;
>  	struct iommu_dma_cookie *iova_cookie;
> +	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
> +						      void *data);
> +	void *fault_data;
>  };
>  
>  static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
> index 1df8c1dcae77..aee9e033012f 100644
> --- a/drivers/iommu/io-pgfault.c
> +++ b/drivers/iommu/io-pgfault.c
> @@ -181,6 +181,13 @@ static void iopf_handle_group(struct work_struct *work)
>   * request completes, outstanding faults will have been dealt with by the time
>   * the PASID is freed.
>   *
> + * Any valid page fault will be eventually routed to an iommu domain and the
> + * page fault handler installed there will get called. The users of this
> + * handling framework should guarantee that the iommu domain could only be
> + * freed after the device has stopped generating page faults (or the iommu
> + * hardware has been set to block the page faults) and the pending page faults
> + * have been flushed.
> + *
>   * Return: 0 on success and <0 on error.
>   */
>  int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
> diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
> index 568e0f64edac..317ab8e8c149 100644
> --- a/drivers/iommu/iommu-sva-lib.c
> +++ b/drivers/iommu/iommu-sva-lib.c
> @@ -72,6 +72,69 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid)
>  }
>  EXPORT_SYMBOL_GPL(iommu_sva_find);
>  
> +/*
> + * I/O page fault handler for SVA
> + *
> + * Copied from io-pgfault.c with mmget_not_zero() added before
> + * mmap_read_lock().

Comment doesn't really belong here, maybe better in the commit message.
Apart from that

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

> + */
> +static enum iommu_page_response_code
> +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
> +{
> +	vm_fault_t ret;
> +	struct mm_struct *mm;
> +	struct vm_area_struct *vma;
> +	unsigned int access_flags = 0;
> +	struct iommu_domain *domain = data;
> +	unsigned int fault_flags = FAULT_FLAG_REMOTE;
> +	struct iommu_fault_page_request *prm = &fault->prm;
> +	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
> +
> +	if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
> +		return status;
> +
> +	mm = domain_to_mm(domain);
> +	if (IS_ERR_OR_NULL(mm) || !mmget_not_zero(mm))
> +		return status;
> +
> +	mmap_read_lock(mm);
> +
> +	vma = find_extend_vma(mm, prm->addr);
> +	if (!vma)
> +		/* Unmapped area */
> +		goto out_put_mm;
> +
> +	if (prm->perm & IOMMU_FAULT_PERM_READ)
> +		access_flags |= VM_READ;
> +
> +	if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
> +		access_flags |= VM_WRITE;
> +		fault_flags |= FAULT_FLAG_WRITE;
> +	}
> +
> +	if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
> +		access_flags |= VM_EXEC;
> +		fault_flags |= FAULT_FLAG_INSTRUCTION;
> +	}
> +
> +	if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
> +		fault_flags |= FAULT_FLAG_USER;
> +
> +	if (access_flags & ~vma->vm_flags)
> +		/* Access fault */
> +		goto out_put_mm;
> +
> +	ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
> +	status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
> +		IOMMU_PAGE_RESP_SUCCESS;
> +
> +out_put_mm:
> +	mmap_read_unlock(mm);
> +	mmput(mm);
> +
> +	return status;
> +}
> +
>  /*
>   * IOMMU SVA driver-oriented interfaces
>   */
> @@ -94,6 +157,8 @@ iommu_sva_alloc_domain(struct bus_type *bus, struct mm_struct *mm)
>  	domain = &sva_domain->domain;
>  	domain->type = IOMMU_DOMAIN_SVA;
>  	domain->ops = bus->iommu_ops->sva_domain_ops;
> +	domain->iopf_handler = iommu_sva_handle_iopf;
> +	domain->fault_data = domain;
>  
>  	return domain;
>  }
> -- 
> 2.25.1
> 
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>, Jason Gunthorpe <jgg@nvidia.com>,
	Christoph Hellwig <hch@infradead.org>,
	Kevin Tian <kevin.tian@intel.com>,
	Ashok Raj <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>,
	Dave Jiang <dave.jiang@intel.com>, Vinod Koul <vkoul@kernel.org>,
	Eric Auger <eric.auger@redhat.com>, Liu Yi L <yi.l.liu@intel.com>,
	Jacob jun Pan <jacob.jun.pan@intel.com>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 08/10] iommu: Prepare IOMMU domain for IOPF
Date: Thu, 19 May 2022 17:40:21 +0100	[thread overview]
Message-ID: <YoZy9fnJlN/RIVY4@myrica> (raw)
In-Reply-To: <20220519072047.2996983-9-baolu.lu@linux.intel.com>

On Thu, May 19, 2022 at 03:20:45PM +0800, Lu Baolu wrote:
> This adds some mechanisms around the iommu_domain so that the I/O page
> fault handling framework could route a page fault to the domain and
> call the fault handler from it.
> 
> Add pointers to the page fault handler and its private data in struct
> iommu_domain. The fault handler will be called with the private data
> as a parameter once a page fault is routed to the domain. Any kernel
> component which owns an iommu domain could install handler and its
> private parameter so that the page fault could be further routed and
> handled.
> 
> This also prepares the SVA implementation to be the first consumer of
> the per-domain page fault handling model.
> 
> Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  include/linux/iommu.h         |  3 ++
>  drivers/iommu/io-pgfault.c    |  7 ++++
>  drivers/iommu/iommu-sva-lib.c | 65 +++++++++++++++++++++++++++++++++++
>  3 files changed, 75 insertions(+)
> 
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index e4ce2fe0e144..45f274b2640d 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -100,6 +100,9 @@ struct iommu_domain {
>  	void *handler_token;
>  	struct iommu_domain_geometry geometry;
>  	struct iommu_dma_cookie *iova_cookie;
> +	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
> +						      void *data);
> +	void *fault_data;
>  };
>  
>  static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
> index 1df8c1dcae77..aee9e033012f 100644
> --- a/drivers/iommu/io-pgfault.c
> +++ b/drivers/iommu/io-pgfault.c
> @@ -181,6 +181,13 @@ static void iopf_handle_group(struct work_struct *work)
>   * request completes, outstanding faults will have been dealt with by the time
>   * the PASID is freed.
>   *
> + * Any valid page fault will be eventually routed to an iommu domain and the
> + * page fault handler installed there will get called. The users of this
> + * handling framework should guarantee that the iommu domain could only be
> + * freed after the device has stopped generating page faults (or the iommu
> + * hardware has been set to block the page faults) and the pending page faults
> + * have been flushed.
> + *
>   * Return: 0 on success and <0 on error.
>   */
>  int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
> diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
> index 568e0f64edac..317ab8e8c149 100644
> --- a/drivers/iommu/iommu-sva-lib.c
> +++ b/drivers/iommu/iommu-sva-lib.c
> @@ -72,6 +72,69 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid)
>  }
>  EXPORT_SYMBOL_GPL(iommu_sva_find);
>  
> +/*
> + * I/O page fault handler for SVA
> + *
> + * Copied from io-pgfault.c with mmget_not_zero() added before
> + * mmap_read_lock().

Comment doesn't really belong here, maybe better in the commit message.
Apart from that

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

> + */
> +static enum iommu_page_response_code
> +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
> +{
> +	vm_fault_t ret;
> +	struct mm_struct *mm;
> +	struct vm_area_struct *vma;
> +	unsigned int access_flags = 0;
> +	struct iommu_domain *domain = data;
> +	unsigned int fault_flags = FAULT_FLAG_REMOTE;
> +	struct iommu_fault_page_request *prm = &fault->prm;
> +	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
> +
> +	if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
> +		return status;
> +
> +	mm = domain_to_mm(domain);
> +	if (IS_ERR_OR_NULL(mm) || !mmget_not_zero(mm))
> +		return status;
> +
> +	mmap_read_lock(mm);
> +
> +	vma = find_extend_vma(mm, prm->addr);
> +	if (!vma)
> +		/* Unmapped area */
> +		goto out_put_mm;
> +
> +	if (prm->perm & IOMMU_FAULT_PERM_READ)
> +		access_flags |= VM_READ;
> +
> +	if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
> +		access_flags |= VM_WRITE;
> +		fault_flags |= FAULT_FLAG_WRITE;
> +	}
> +
> +	if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
> +		access_flags |= VM_EXEC;
> +		fault_flags |= FAULT_FLAG_INSTRUCTION;
> +	}
> +
> +	if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
> +		fault_flags |= FAULT_FLAG_USER;
> +
> +	if (access_flags & ~vma->vm_flags)
> +		/* Access fault */
> +		goto out_put_mm;
> +
> +	ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
> +	status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
> +		IOMMU_PAGE_RESP_SUCCESS;
> +
> +out_put_mm:
> +	mmap_read_unlock(mm);
> +	mmput(mm);
> +
> +	return status;
> +}
> +
>  /*
>   * IOMMU SVA driver-oriented interfaces
>   */
> @@ -94,6 +157,8 @@ iommu_sva_alloc_domain(struct bus_type *bus, struct mm_struct *mm)
>  	domain = &sva_domain->domain;
>  	domain->type = IOMMU_DOMAIN_SVA;
>  	domain->ops = bus->iommu_ops->sva_domain_ops;
> +	domain->iopf_handler = iommu_sva_handle_iopf;
> +	domain->fault_data = domain;
>  
>  	return domain;
>  }
> -- 
> 2.25.1
> 

  reply	other threads:[~2022-05-19 16:40 UTC|newest]

Thread overview: 100+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-19  7:20 [PATCH v7 00/10] iommu: SVA and IOPF refactoring Lu Baolu
2022-05-19  7:20 ` Lu Baolu
2022-05-19  7:20 ` [PATCH v7 01/10] iommu: Add pasids field in struct iommu_device Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19 10:37   ` Jean-Philippe Brucker
2022-05-19 10:37     ` Jean-Philippe Brucker
2022-05-19 11:55     ` Baolu Lu
2022-05-19 11:55       ` Baolu Lu
2022-05-24  9:24   ` Tian, Kevin
2022-05-24  9:24     ` Tian, Kevin
2022-05-25  2:03     ` Baolu Lu
2022-05-25  2:03       ` Baolu Lu
2022-05-25  2:13       ` Baolu Lu
2022-05-25  2:13         ` Baolu Lu
2022-05-19  7:20 ` [PATCH v7 02/10] iommu: Remove SVM_FLAG_SUPERVISOR_MODE support Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19 16:22   ` Jean-Philippe Brucker
2022-05-19 16:22     ` Jean-Philippe Brucker
2022-05-24  9:27   ` Tian, Kevin
2022-05-24  9:27     ` Tian, Kevin
2022-05-19  7:20 ` [PATCH v7 03/10] iommu/sva: Add iommu_sva_domain support Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19 16:33   ` Jean-Philippe Brucker
2022-05-19 16:33     ` Jean-Philippe Brucker
2022-05-20  4:55     ` Baolu Lu
2022-05-20  4:55       ` Baolu Lu
2022-05-23  7:12   ` Baolu Lu
2022-05-23  7:12     ` Baolu Lu
2022-05-24  9:44     ` Tian, Kevin
2022-05-24  9:44       ` Tian, Kevin
2022-05-25  2:18       ` Baolu Lu
2022-05-25  2:18         ` Baolu Lu
2022-05-24  9:39   ` Tian, Kevin
2022-05-24  9:39     ` Tian, Kevin
2022-05-24 13:38     ` Jason Gunthorpe
2022-05-24 13:38       ` Jason Gunthorpe via iommu
2022-05-25  0:44       ` Tian, Kevin
2022-05-25  0:44         ` Tian, Kevin
2022-05-25  2:38         ` Baolu Lu
2022-05-25  2:38           ` Baolu Lu
2022-05-25  4:50     ` Baolu Lu
2022-05-25  4:50       ` Baolu Lu
2022-05-24 13:44   ` Jason Gunthorpe
2022-05-24 13:44     ` Jason Gunthorpe via iommu
2022-05-25  5:19     ` Baolu Lu
2022-05-25  5:19       ` Baolu Lu
2022-05-25 15:25       ` Jason Gunthorpe
2022-05-25 15:25         ` Jason Gunthorpe via iommu
2022-05-26  1:03         ` Baolu Lu
2022-05-26  1:03           ` Baolu Lu
2022-05-25  5:33     ` Baolu Lu
2022-05-25  5:33       ` Baolu Lu
2022-05-24 14:36   ` Robin Murphy
2022-05-24 14:36     ` Robin Murphy
2022-05-25  6:20     ` Baolu Lu
2022-05-25  6:20       ` Baolu Lu
2022-05-25 10:07       ` Robin Murphy
2022-05-25 10:07         ` Robin Murphy
2022-05-25 11:06         ` Jean-Philippe Brucker
2022-05-25 11:06           ` Jean-Philippe Brucker
2022-05-25 13:11           ` Baolu Lu
2022-05-25 13:11             ` Baolu Lu
2022-05-19  7:20 ` [PATCH v7 04/10] iommu/vt-d: Add SVA domain support Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19  7:20 ` [PATCH v7 05/10] arm-smmu-v3/sva: " Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19 16:37   ` Jean-Philippe Brucker
2022-05-19 16:37     ` Jean-Philippe Brucker
2022-05-19  7:20 ` [PATCH v7 06/10] iommu/sva: Refactoring iommu_sva_bind/unbind_device() Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19 16:39   ` Jean-Philippe Brucker
2022-05-19 16:39     ` Jean-Philippe Brucker
2022-05-20  6:38     ` Baolu Lu
2022-05-20  6:38       ` Baolu Lu
2022-05-20 11:28       ` Jean-Philippe Brucker
2022-05-20 11:28         ` Jean-Philippe Brucker
2022-05-23  3:07         ` Baolu Lu
2022-05-23  3:07           ` Baolu Lu
2022-05-24 10:22   ` Tian, Kevin
2022-05-24 10:22     ` Tian, Kevin
2022-05-24 10:57     ` Jean-Philippe Brucker
2022-05-24 10:57       ` Jean-Philippe Brucker
2022-05-25  2:04       ` Tian, Kevin
2022-05-25  2:04         ` Tian, Kevin
2022-05-25  7:29         ` Jean-Philippe Brucker
2022-05-25  7:29           ` Jean-Philippe Brucker
2022-06-02  6:46           ` Tian, Kevin
2022-06-02  6:46             ` Tian, Kevin
2022-05-19  7:20 ` [PATCH v7 07/10] iommu: Remove SVA related callbacks from iommu ops Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-24 10:23   ` Tian, Kevin
2022-05-24 10:23     ` Tian, Kevin
2022-05-19  7:20 ` [PATCH v7 08/10] iommu: Prepare IOMMU domain for IOPF Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19 16:40   ` Jean-Philippe Brucker [this message]
2022-05-19 16:40     ` Jean-Philippe Brucker
2022-05-19  7:20 ` [PATCH v7 09/10] iommu: Per-domain I/O page fault handling Lu Baolu
2022-05-19  7:20   ` Lu Baolu
2022-05-19  7:20 ` [PATCH v7 10/10] iommu: Rename iommu-sva-lib.{c,h} Lu Baolu
2022-05-19  7:20   ` Lu Baolu

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