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[v4,0/6] Define EINVAL as device/domain incompatibility

Message ID cover.1663744983.git.nicolinc@nvidia.com
Headers show
Series Define EINVAL as device/domain incompatibility | expand

Message

Nicolin Chen Sept. 21, 2022, 8:22 a.m. UTC 
This series is to replace the previous EMEDIUMTYPE patch in a VFIO series:
https://lore.kernel.org/kvm/Yxnt9uQTmbqul5lf@8bytes.org/

The purpose is to regulate all existing ->attach_dev callback functions to
use EINVAL exclusively for an incompatibility error between a device and a
domain. This allows VFIO and IOMMUFD to detect such a soft error, and then
try a different domain with the same device.

Among all the patches, the first two are preparatory changes. And then one
patch to update kdocs and another three patches for the enforcement effort.

Although it might be ideal to merge the previous VFIO series together with
this series, given the number of new changes, the review in the IOMMU list
might need a couple of rounds to finalize. Also, considering that v6.0 is
at rc5 now, perhaps we could merge this IOMMU series and the VFIO one in
different cycles to avoid merge conflicts. If there's less concern for it,
I can respin the finalized version of this series with the previous VFIO
one to merge together into the VFIO tree.

This series is also available on Github:
https://github.com/nicolinc/iommufd/commits/iommu_attach_dev-v4

Changelog
v4:
 * Refined kdocs with Kevin's input
 * Fixed an EINVAL conversion in the intel_iommu driver
 * Added missing error-out routines in the msm_iommu driver
 * Added a missing EINVAL conversion in the virtio-iommu driver
 * Updated commit message and added "Reviewed-by" from Kevin to the last patch
v3: https://lore.kernel.org/linux-iommu/cover.1663227492.git.nicolinc@nvidia.com/
 * Added "Reviewed-by" from Vasant to the AMD patch
 * Dropped all unnecessary errno enforcement patches
 * Updated kdocs and brought back the kdocs for the helpers
 * Added a separate patch to propagate "ret" for potential EINVALs
 * Converted to ENODEV those existing EINVAL places that are device-specific
v2: https://lore.kernel.org/linux-iommu/20220914051234.10006-1-nicolinc@nvidia.com/
 * Fixed kdocs format
 * Grouped with the virtio patch from Jean (with a small change)
 * Separated previous ENODEV and EINVAL changes to per-driver ones
 * Redone some of the changes to have explicit return values in the
   ->attach_dev() callback functions or their direct sub-functions.
v1: https://lore.kernel.org/linux-iommu/20220913082448.31120-1-nicolinc@nvidia.com/

Thanks!

Nicolin Chen (6):
  iommu/msm: Fix error-out routine in msm_iommu_attach_dev()
  iommu/amd: Drop unnecessary checks in amd_iommu_attach_device()
  iommu: Add return value rules to attach_dev op and APIs
  iommu: Regulate EINVAL in ->attach_dev callback functions
  iommu: Use EINVAL for incompatible device/domain in ->attach_dev
  iommu: Propagate return value in ->attach_dev callback functions

 drivers/iommu/amd/iommu.c                   | 12 +----
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 11 +---
 drivers/iommu/arm/arm-smmu/arm-smmu.c       |  3 --
 drivers/iommu/arm/arm-smmu/qcom_iommu.c     |  7 +--
 drivers/iommu/fsl_pamu.c                    |  2 +-
 drivers/iommu/fsl_pamu_domain.c             |  4 +-
 drivers/iommu/intel/iommu.c                 | 10 ++--
 drivers/iommu/intel/pasid.c                 |  6 ++-
 drivers/iommu/iommu.c                       | 22 ++++++++
 drivers/iommu/ipmmu-vmsa.c                  |  2 -
 drivers/iommu/msm_iommu.c                   | 59 +++++++++++----------
 drivers/iommu/mtk_iommu.c                   |  4 +-
 drivers/iommu/omap-iommu.c                  |  6 +--
 drivers/iommu/sprd-iommu.c                  |  4 +-
 drivers/iommu/tegra-gart.c                  |  2 +-
 drivers/iommu/virtio-iommu.c                |  7 ++-
 include/linux/iommu.h                       | 12 +++++
 17 files changed, 90 insertions(+), 83 deletions(-)

Comments

Baolu Lu Sept. 22, 2022, 2:16 a.m. UTC | #1 
On 9/21/22 4:23 PM, Nicolin Chen wrote:
> Following the new rules in include/linux/iommu.h kdocs, update all drivers
> ->attach_dev callback functions to return EINVAL in the failure paths that
> are related to domain incompatibility.
> 
> Also, drop adjacent error prints to prevent a kernel log spam.
> 
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> ---
>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 11 +----------
>   drivers/iommu/arm/arm-smmu/arm-smmu.c       |  3 ---
>   drivers/iommu/arm/arm-smmu/qcom_iommu.c     |  7 +------
>   drivers/iommu/intel/iommu.c                 | 10 +++-------
>   drivers/iommu/ipmmu-vmsa.c                  |  2 --
>   drivers/iommu/omap-iommu.c                  |  2 +-
>   drivers/iommu/sprd-iommu.c                  |  4 +---
>   drivers/iommu/tegra-gart.c                  |  2 +-
>   drivers/iommu/virtio-iommu.c                |  3 +--
>   9 files changed, 9 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index d32b02336411..f96f8aad8280 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2429,23 +2429,14 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
>   			goto out_unlock;
>   		}
>   	} else if (smmu_domain->smmu != smmu) {
> -		dev_err(dev,
> -			"cannot attach to SMMU %s (upstream of %s)\n",
> -			dev_name(smmu_domain->smmu->dev),
> -			dev_name(smmu->dev));
> -		ret = -ENXIO;
> +		ret = -EINVAL;
>   		goto out_unlock;
>   	} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 &&
>   		   master->ssid_bits != smmu_domain->s1_cfg.s1cdmax) {
> -		dev_err(dev,
> -			"cannot attach to incompatible domain (%u SSID bits != %u)\n",
> -			smmu_domain->s1_cfg.s1cdmax, master->ssid_bits);
>   		ret = -EINVAL;
>   		goto out_unlock;
>   	} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 &&
>   		   smmu_domain->stall_enabled != master->stall_enabled) {
> -		dev_err(dev, "cannot attach to stall-%s domain\n",
> -			smmu_domain->stall_enabled ? "enabled" : "disabled");
>   		ret = -EINVAL;
>   		goto out_unlock;
>   	}
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> index dfa82df00342..dbd12da31707 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> @@ -1167,9 +1167,6 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
>   	 * different SMMUs.
>   	 */
>   	if (smmu_domain->smmu != smmu) {
> -		dev_err(dev,
> -			"cannot attach to SMMU %s whilst already attached to domain on SMMU %s\n",
> -			dev_name(smmu_domain->smmu->dev), dev_name(smmu->dev));
>   		ret = -EINVAL;
>   		goto rpm_put;
>   	}
> diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
> index 17235116d3bb..37c5ddc212c1 100644
> --- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
> +++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
> @@ -381,13 +381,8 @@ static int qcom_iommu_attach_dev(struct iommu_domain *domain, struct device *dev
>   	 * Sanity check the domain. We don't support domains across
>   	 * different IOMMUs.
>   	 */
> -	if (qcom_domain->iommu != qcom_iommu) {
> -		dev_err(dev, "cannot attach to IOMMU %s while already "
> -			"attached to domain on IOMMU %s\n",
> -			dev_name(qcom_domain->iommu->dev),
> -			dev_name(qcom_iommu->dev));
> +	if (qcom_domain->iommu != qcom_iommu)
>   		return -EINVAL;
> -	}
>   
>   	return 0;
>   }
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 1f2cd43cf9bc..51ef42b1bd4e 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4158,19 +4158,15 @@ static int prepare_domain_attach_device(struct iommu_domain *domain,
>   		return -ENODEV;
>   
>   	if (dmar_domain->force_snooping && !ecap_sc_support(iommu->ecap))
> -		return -EOPNOTSUPP;
> +		return -EINVAL;
>   
>   	/* check if this iommu agaw is sufficient for max mapped address */
>   	addr_width = agaw_to_width(iommu->agaw);
>   	if (addr_width > cap_mgaw(iommu->cap))
>   		addr_width = cap_mgaw(iommu->cap);
>   
> -	if (dmar_domain->max_addr > (1LL << addr_width)) {
> -		dev_err(dev, "%s: iommu width (%d) is not "
> -		        "sufficient for the mapped address (%llx)\n",
> -		        __func__, addr_width, dmar_domain->max_addr);
> -		return -EFAULT;
> -	}
> +	if (dmar_domain->max_addr > (1LL << addr_width))
> +		return -EINVAL;
>   	dmar_domain->gaw = addr_width;
>   
>   	/*
> diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
> index 1d42084d0276..f5217a4cb9b3 100644
> --- a/drivers/iommu/ipmmu-vmsa.c
> +++ b/drivers/iommu/ipmmu-vmsa.c
> @@ -628,8 +628,6 @@ static int ipmmu_attach_device(struct iommu_domain *io_domain,
>   		 * Something is wrong, we can't attach two devices using
>   		 * different IOMMUs to the same domain.
>   		 */
> -		dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
> -			dev_name(mmu->dev), dev_name(domain->mmu->dev));
>   		ret = -EINVAL;
>   	} else
>   		dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
> diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
> index 447e40d55918..be12f49140c7 100644
> --- a/drivers/iommu/omap-iommu.c
> +++ b/drivers/iommu/omap-iommu.c
> @@ -1472,7 +1472,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
>   	/* only a single client device can be attached to a domain */
>   	if (omap_domain->dev) {
>   		dev_err(dev, "iommu domain is already attached\n");
> -		ret = -EBUSY;
> +		ret = -EINVAL;
>   		goto out;
>   	}
>   
> diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c
> index 511959c8a14d..945576039c9e 100644
> --- a/drivers/iommu/sprd-iommu.c
> +++ b/drivers/iommu/sprd-iommu.c
> @@ -237,10 +237,8 @@ static int sprd_iommu_attach_device(struct iommu_domain *domain,
>   	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
>   	size_t pgt_size = sprd_iommu_pgt_size(domain);
>   
> -	if (dom->sdev) {
> -		pr_err("There's already a device attached to this domain.\n");
> +	if (dom->sdev)
>   		return -EINVAL;
> -	}
>   
>   	dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL);
>   	if (!dom->pgt_va)
> diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
> index e5ca3cf1a949..ed53279d1106 100644
> --- a/drivers/iommu/tegra-gart.c
> +++ b/drivers/iommu/tegra-gart.c
> @@ -112,7 +112,7 @@ static int gart_iommu_attach_dev(struct iommu_domain *domain,
>   	spin_lock(&gart->dom_lock);
>   
>   	if (gart->active_domain && gart->active_domain != domain) {
> -		ret = -EBUSY;
> +		ret = -EINVAL;
>   	} else if (dev_iommu_priv_get(dev) != domain) {
>   		dev_iommu_priv_set(dev, domain);
>   		gart->active_domain = domain;
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> index 4c652773fd6c..87128266b6e3 100644
> --- a/drivers/iommu/virtio-iommu.c
> +++ b/drivers/iommu/virtio-iommu.c
> @@ -733,8 +733,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
>   		 */
>   		ret = viommu_domain_finalise(vdev, domain);
>   	} else if (vdomain->viommu != vdev->viommu) {
> -		dev_err(dev, "cannot attach to foreign vIOMMU\n");
> -		ret = -EXDEV;
> +		ret = -EINVAL;
>   	}
>   	mutex_unlock(&vdomain->mutex);
>   

For iommu/vt-d changes:

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu