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From: Alex Williamson <alex.williamson@redhat.com>
To: Liu Yi L <yi.l.liu@intel.com>
Cc: jean-philippe@linaro.org, kevin.tian@intel.com,
	ashok.raj@intel.com, kvm@vger.kernel.org,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	yi.y.sun@intel.com, hao.wu@intel.com, jun.j.tian@intel.com
Subject: Re: [PATCH v3 02/14] iommu: Report domain nesting info
Date: Thu, 2 Jul 2020 11:54:54 -0600	[thread overview]
Message-ID: <20200702115454.058bd198@x1.home> (raw)
In-Reply-To: <1592988927-48009-3-git-send-email-yi.l.liu@intel.com>

On Wed, 24 Jun 2020 01:55:15 -0700
Liu Yi L <yi.l.liu@intel.com> wrote:

> IOMMUs that support nesting translation needs report the capability info
> to userspace, e.g. the format of first level/stage paging structures.
> 
> This patch reports nesting info by DOMAIN_ATTR_NESTING. Caller can get
> nesting info after setting DOMAIN_ATTR_NESTING.
> 
> v2 -> v3:
> *) remvoe cap/ecap_mask in iommu_nesting_info.
> *) reuse DOMAIN_ATTR_NESTING to get nesting info.
> *) return an empty iommu_nesting_info for SMMU drivers per Jean'
>    suggestion.
> 
> Cc: Kevin Tian <kevin.tian@intel.com>
> CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Lu Baolu <baolu.lu@linux.intel.com>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>  drivers/iommu/arm-smmu-v3.c | 29 ++++++++++++++++++++--
>  drivers/iommu/arm-smmu.c    | 29 ++++++++++++++++++++--
>  include/uapi/linux/iommu.h  | 59 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 113 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index f578677..0c45d4d 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -3019,6 +3019,32 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
>  	return group;
>  }
>  
> +static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
> +					void *data)
> +{
> +	struct iommu_nesting_info *info = (struct iommu_nesting_info *) data;
> +	u32 size;
> +
> +	if (!info || smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
> +		return -ENODEV;
> +
> +	size = sizeof(struct iommu_nesting_info);
> +
> +	/*
> +	 * if provided buffer size is not equal to the size, should
> +	 * return 0 and also the expected buffer size to caller.
> +	 */
> +	if (info->size != size) {
> +		info->size = size;
> +		return 0;
> +	}
> +
> +	/* report an empty iommu_nesting_info for now */
> +	memset(info, 0x0, size);
> +	info->size = size;
> +	return 0;
> +}
> +
>  static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
>  				    enum iommu_attr attr, void *data)
>  {
> @@ -3028,8 +3054,7 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
>  	case IOMMU_DOMAIN_UNMANAGED:
>  		switch (attr) {
>  		case DOMAIN_ATTR_NESTING:
> -			*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
> -			return 0;
> +			return arm_smmu_domain_nesting_info(smmu_domain, data);
>  		default:
>  			return -ENODEV;
>  		}
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 243bc4c..908607d 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1506,6 +1506,32 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
>  	return group;
>  }
>  
> +static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
> +					void *data)
> +{
> +	struct iommu_nesting_info *info = (struct iommu_nesting_info *) data;
> +	u32 size;
> +
> +	if (!info || smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
> +		return -ENODEV;
> +
> +	size = sizeof(struct iommu_nesting_info);
> +
> +	/*
> +	 * if provided buffer size is not equal to the size, should
> +	 * return 0 and also the expected buffer size to caller.
> +	 */
> +	if (info->size != size) {
> +		info->size = size;
> +		return 0;
> +	}
> +
> +	/* report an empty iommu_nesting_info for now */
> +	memset(info, 0x0, size);
> +	info->size = size;
> +	return 0;
> +}
> +
>  static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
>  				    enum iommu_attr attr, void *data)
>  {
> @@ -1515,8 +1541,7 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
>  	case IOMMU_DOMAIN_UNMANAGED:
>  		switch (attr) {
>  		case DOMAIN_ATTR_NESTING:
> -			*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
> -			return 0;
> +			return arm_smmu_domain_nesting_info(smmu_domain, data);
>  		default:
>  			return -ENODEV;
>  		}
> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
> index 1afc661..898c99a 100644
> --- a/include/uapi/linux/iommu.h
> +++ b/include/uapi/linux/iommu.h
> @@ -332,4 +332,63 @@ struct iommu_gpasid_bind_data {
>  	} vendor;
>  };
>  
> +/*
> + * struct iommu_nesting_info - Information for nesting-capable IOMMU.
> + *				user space should check it before using
> + *				nesting capability.
> + *
> + * @size:	size of the whole structure
> + * @format:	PASID table entry format, the same definition with
> + *		@format of struct iommu_gpasid_bind_data.
> + * @features:	supported nesting features.
> + * @flags:	currently reserved for future extension.
> + * @data:	vendor specific cap info.
> + *
> + * +---------------+----------------------------------------------------+
> + * | feature       |  Notes                                             |
> + * +===============+====================================================+
> + * | SYSWIDE_PASID |  Kernel manages PASID in system wide, PASIDs used  |
> + * |               |  in the system should be allocated by host kernel  |
> + * +---------------+----------------------------------------------------+
> + * | BIND_PGTBL    |  bind page tables to host PASID, the PASID could   |
> + * |               |  either be a host PASID passed in bind request or  |
> + * |               |  default PASIDs (e.g. default PASID of aux-domain) |
> + * +---------------+----------------------------------------------------+
> + * | CACHE_INVLD   |  mandatory feature for nesting capable IOMMU       |
> + * +---------------+----------------------------------------------------+

Agree with the previous comments on these descriptions and Kevin's
suggestions.

> + *
> + */
> +struct iommu_nesting_info {
> +	__u32	size;
> +	__u32	format;
> +	__u32	features;
> +#define IOMMU_NESTING_FEAT_SYSWIDE_PASID	(1 << 0)
> +#define IOMMU_NESTING_FEAT_BIND_PGTBL		(1 << 1)
> +#define IOMMU_NESTING_FEAT_CACHE_INVLD		(1 << 2)
> +	__u32	flags;
> +	__u8	data[];

How does the user determine which vendor structure is provided in
data[]?  Thanks,

Alex

> +};
> +
> +/*
> + * struct iommu_nesting_info_vtd - Intel VT-d specific nesting info
> + *
> + *
> + * @flags:	VT-d specific flags. Currently reserved for future
> + *		extension.
> + * @addr_width:	The output addr width of first level/stage translation
> + * @pasid_bits:	Maximum supported PASID bits, 0 represents no PASID
> + *		support.
> + * @cap_reg:	Describe basic capabilities as defined in VT-d capability
> + *		register.
> + * @ecap_reg:	Describe the extended capabilities as defined in VT-d
> + *		extended capability register.
> + */
> +struct iommu_nesting_info_vtd {
> +	__u32	flags;
> +	__u16	addr_width;
> +	__u16	pasid_bits;
> +	__u64	cap_reg;
> +	__u64	ecap_reg;
> +};
> +
>  #endif /* _UAPI_IOMMU_H */

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  parent reply	other threads:[~2020-07-02 17:55 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-24  8:55 [PATCH v3 00/14] vfio: expose virtual Shared Virtual Addressing to VMs Liu Yi L
2020-06-24  8:55 ` [PATCH v3 01/14] vfio/type1: Refactor vfio_iommu_type1_ioctl() Liu Yi L
2020-07-02 21:21   ` Alex Williamson
2020-07-03  3:46     ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 02/14] iommu: Report domain nesting info Liu Yi L
2020-06-26  7:47   ` Jean-Philippe Brucker
2020-06-26 16:04     ` Robin Murphy
2020-06-27  6:53       ` Liu, Yi L
2020-06-30  1:20         ` Tian, Kevin
2020-06-27  6:14     ` Liu, Yi L
2020-06-29  9:24   ` Stefan Hajnoczi
2020-06-29 12:23     ` Liu, Yi L
2020-06-30  2:00       ` Tian, Kevin
2020-06-30  3:45         ` Liu, Yi L
2020-07-03  9:59         ` Stefan Hajnoczi
2020-07-02 17:54   ` Alex Williamson [this message]
2020-07-03  3:53     ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 03/14] vfio/type1: Report iommu nesting info to userspace Liu Yi L
2020-07-02 18:38   ` Alex Williamson
2020-07-03  6:05     ` Liu, Yi L
2020-07-03 13:03       ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 04/14] vfio: Add PASID allocation/free support Liu Yi L
2020-07-02 21:17   ` Alex Williamson
2020-07-03  6:08     ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 05/14] iommu/vt-d: Support setting ioasid set to domain Liu Yi L
2020-06-24  8:55 ` [PATCH v3 06/14] vfio/type1: Add VFIO_IOMMU_PASID_REQUEST (alloc/free) Liu Yi L
2020-07-02 21:18   ` Alex Williamson
2020-07-03  6:28     ` Liu, Yi L
2020-07-08  8:16       ` Liu, Yi L
2020-07-08 19:54         ` Alex Williamson
2020-07-09  0:32           ` Liu, Yi L
2020-07-09  1:56             ` Tian, Kevin
2020-07-09  2:08               ` Liu, Yi L
2020-07-09  2:18                 ` Tian, Kevin
2020-07-09  2:26                   ` Liu, Yi L
2020-07-09  7:16                     ` Liu, Yi L
2020-07-09 14:27                       ` Alex Williamson
2020-07-09 18:05                         ` Jacob Pan
2020-07-10  5:39                         ` Liu, Yi L
2020-07-10 12:55                           ` Alex Williamson
2020-07-10 13:03                             ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 07/14] iommu: Pass domain to sva_unbind_gpasid() Liu Yi L
2020-06-24  8:55 ` [PATCH v3 08/14] iommu/vt-d: Check ownership for PASIDs from user-space Liu Yi L
2020-06-24  8:55 ` [PATCH v3 09/14] vfio/type1: Support binding guest page tables to PASID Liu Yi L
2020-07-02 21:19   ` Alex Williamson
2020-07-03  6:46     ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 10/14] vfio/type1: Allow invalidating first-level/stage IOMMU cache Liu Yi L
2020-07-02 21:19   ` Alex Williamson
2020-07-03  3:47     ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 11/14] vfio/type1: Add vSVA support for IOMMU-backed mdevs Liu Yi L
2020-06-24  8:55 ` [PATCH v3 12/14] vfio/pci: Expose PCIe PASID capability to guest Liu Yi L
2020-06-24  8:55 ` [PATCH v3 13/14] vfio: Document dual stage control Liu Yi L
2020-06-29  9:21   ` Stefan Hajnoczi
2020-06-29  9:24     ` Liu, Yi L
2020-06-24  8:55 ` [PATCH v3 14/14] iommu/vt-d: Support reporting nesting capability info Liu Yi L

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