From 79218fd0b38bb05e8dcb80a49342836274046432 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:00:45 -0700 Subject: [PATCH 1/5] iommu/amd: Drop unnecessary checks in amd_iommu_attach_device() The same checks are done in amd_iommu_probe_device(). If any of them fails there, then the device won't get a group, so there's no way for it to even reach amd_iommu_attach_device anymore. Link: https://lore.kernel.org/r/c054654a81f2b675c73108fe4bf10e45335a721a.1666042872.git.nicolinc@nvidia.com Suggested-by: Robin Murphy Cc: Joerg Roedel Cc: Suravee Suthikulpanit Reviewed-by: Vasant Hegde Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/amd/iommu.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index d3b39d0416fa3..45299eb7e8e30 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2155,21 +2155,13 @@ static void amd_iommu_detach_device(struct iommu_domain *dom, static int amd_iommu_attach_device(struct iommu_domain *dom, struct device *dev) { + struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev); struct protection_domain *domain = to_pdomain(dom); - struct iommu_dev_data *dev_data; - struct amd_iommu *iommu; + struct amd_iommu *iommu = rlookup_amd_iommu(dev); int ret; - if (!check_device(dev)) - return -EINVAL; - - dev_data = dev_iommu_priv_get(dev); dev_data->defer_attach = false; - iommu = rlookup_amd_iommu(dev); - if (!iommu) - return -EINVAL; - if (dev_data->domain) detach_device(dev); From 00208852d351ca6e4a8b9ff0c5376fa3a8ed8eaa Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:01:22 -0700 Subject: [PATCH 2/5] iommu: Add return value rules to attach_dev op and APIs Cases like VFIO wish to attach a device to an existing domain that was not allocated specifically from the device. This raises a condition where the IOMMU driver can fail the domain attach because the domain and device are incompatible with each other. This is a soft failure that can be resolved by using a different domain. Provide a dedicated errno EINVAL from the IOMMU driver during attach that the reason why the attach failed is because of domain incompatibility. VFIO can use this to know that the attach is a soft failure and it should continue searching. Otherwise, the attach will be a hard failure and VFIO will return the code to userspace. Update kdocs to add rules of return value to the attach_dev op and APIs. Link: https://lore.kernel.org/r/bd56d93c18621104a0fa1b0de31e9b760b81b769.1666042872.git.nicolinc@nvidia.com Suggested-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Reviewed-by: Lu Baolu Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommu.c | 24 ++++++++++++++++++++++++ include/linux/iommu.h | 12 ++++++++++++ 2 files changed, 36 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 65a3b3d886dc0..972731f0b328a 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1949,6 +1949,18 @@ static int __iommu_attach_device(struct iommu_domain *domain, return ret; } +/** + * iommu_attach_device - Attach an IOMMU domain to a device + * @domain: IOMMU domain to attach + * @dev: Device that will be attached + * + * Returns 0 on success and error code on failure + * + * Note that EINVAL can be treated as a soft failure, indicating + * that certain configuration of the domain is incompatible with + * the device. In this case attaching a different domain to the + * device may succeed. + */ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) { struct iommu_group *group; @@ -2075,6 +2087,18 @@ static int __iommu_attach_group(struct iommu_domain *domain, return ret; } +/** + * iommu_attach_group - Attach an IOMMU domain to an IOMMU group + * @domain: IOMMU domain to attach + * @group: IOMMU group that will be attached + * + * Returns 0 on success and error code on failure + * + * Note that EINVAL can be treated as a soft failure, indicating + * that certain configuration of the domain is incompatible with + * the group. In this case attaching a different domain to the + * group may succeed. + */ int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) { int ret; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 3c9da1f8979e3..857898d102b36 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -266,6 +266,18 @@ struct iommu_ops { /** * struct iommu_domain_ops - domain specific operations * @attach_dev: attach an iommu domain to a device + * Return: + * * 0 - success + * * EINVAL - can indicate that device and domain are incompatible due to + * some previous configuration of the domain, in which case the + * driver shouldn't log an error, since it is legitimate for a + * caller to test reuse of existing domains. Otherwise, it may + * still represent some other fundamental problem + * * ENOMEM - out of memory + * * ENOSPC - non-ENOMEM type of resource allocation failures + * * EBUSY - device is attached to a domain and cannot be changed + * * ENODEV - device specific errors, not able to be attached + * * - treated as ENODEV by the caller. Use is discouraged * @detach_dev: detach an iommu domain from a device * @map: map a physically contiguous memory region to an iommu domain * @map_pages: map a physically contiguous set of pages of the same size to From bd7ebb7719356d750b1b4d671535922bae43fb3b Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:02:13 -0700 Subject: [PATCH 3/5] iommu: Regulate EINVAL in ->attach_dev callback functions Following the new rules in include/linux/iommu.h kdocs, EINVAL now can be used to indicate that domain and device are incompatible by a caller that treats it as a soft failure and tries attaching to another domain. On the other hand, there are ->attach_dev callback functions returning it for obvious device-specific errors. They will result in some inefficiency in the caller handling routine. Update these places to corresponding errnos following the new rules. Link: https://lore.kernel.org/r/5924c03bea637f05feb2a20d624bae086b555ec5.1666042872.git.nicolinc@nvidia.com Reviewed-by: Jean-Philippe Brucker Reviewed-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/fsl_pamu.c | 2 +- drivers/iommu/fsl_pamu_domain.c | 4 ++-- drivers/iommu/intel/pasid.c | 6 ++++-- drivers/iommu/mtk_iommu.c | 2 +- drivers/iommu/omap-iommu.c | 4 ++-- drivers/iommu/virtio-iommu.c | 2 +- 6 files changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/fsl_pamu.c b/drivers/iommu/fsl_pamu.c index 0d03f837a5d4e..2eb3211c81677 100644 --- a/drivers/iommu/fsl_pamu.c +++ b/drivers/iommu/fsl_pamu.c @@ -211,7 +211,7 @@ int pamu_config_ppaace(int liodn, u32 omi, u32 stashid, int prot) ppaace->op_encode.index_ot.omi = omi; } else if (~omi != 0) { pr_debug("bad operation mapping index: %d\n", omi); - return -EINVAL; + return -ENODEV; } /* configure stash id */ diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c index fa20f4b03e12d..4408ac3c49b61 100644 --- a/drivers/iommu/fsl_pamu_domain.c +++ b/drivers/iommu/fsl_pamu_domain.c @@ -258,7 +258,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain, liodn = of_get_property(dev->of_node, "fsl,liodn", &len); if (!liodn) { pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node); - return -EINVAL; + return -ENODEV; } spin_lock_irqsave(&dma_domain->domain_lock, flags); @@ -267,7 +267,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain, if (liodn[i] >= PAACE_NUMBER_ENTRIES) { pr_debug("Invalid liodn %d, attach device failed for %pOF\n", liodn[i], dev->of_node); - ret = -EINVAL; + ret = -ENODEV; break; } diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index c30ddac40ee5f..95d73f19ab619 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -101,8 +101,10 @@ int intel_pasid_alloc_table(struct device *dev) might_sleep(); info = dev_iommu_priv_get(dev); - if (WARN_ON(!info || !dev_is_pci(dev) || info->pasid_table)) - return -EINVAL; + if (WARN_ON(!info || !dev_is_pci(dev))) + return -ENODEV; + if (WARN_ON(info->pasid_table)) + return -EEXIST; pasid_table = kzalloc(sizeof(*pasid_table), GFP_KERNEL); if (!pasid_table) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 2ab2ecfe01f80..eda441d0c6b68 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -609,7 +609,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom, dom->iop = alloc_io_pgtable_ops(ARM_V7S, &dom->cfg, data); if (!dom->iop) { dev_err(data->dev, "Failed to alloc io pgtable\n"); - return -EINVAL; + return -ENOMEM; } /* Update our support page sizes bitmap */ diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index 07ee2600113c2..3f153f9e0ac59 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -1414,7 +1414,7 @@ static int omap_iommu_attach_init(struct device *dev, odomain->num_iommus = omap_iommu_count(dev); if (!odomain->num_iommus) - return -EINVAL; + return -ENODEV; odomain->iommus = kcalloc(odomain->num_iommus, sizeof(*iommu), GFP_ATOMIC); @@ -1464,7 +1464,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev) if (!arch_data || !arch_data->iommu_dev) { dev_err(dev, "device doesn't have an associated iommu\n"); - return -EINVAL; + return -ENODEV; } spin_lock(&omap_domain->lock); diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 8b1b5c270e502..0b64e7f64e68c 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -670,7 +670,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev, dev_err(vdev->dev, "granule 0x%lx larger than system page size 0x%lx\n", viommu_page_size, PAGE_SIZE); - return -EINVAL; + return -ENODEV; } ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, From f4a14773579302e5f0c4bf80b03f0db7ce67f2ce Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:02:21 -0700 Subject: [PATCH 4/5] iommu: Use EINVAL for incompatible device/domain in ->attach_dev 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. Link: https://lore.kernel.org/r/f52a07f7320da94afe575c9631340d0019a203a7.1666042873.git.nicolinc@nvidia.com Reviewed-by: Jean-Philippe Brucker Reviewed-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- 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 6d5df91c5c465..8b0a1e476d44d 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2430,23 +2430,14 @@ 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 30dab1418e3ff..719fbca1fe52a 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1150,9 +1150,6 @@ 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 3869c3ecda8cd..bfd7b51eb5dbf 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 48cdcd0a5cf34..6f1a59206d2e0 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4194,19 +4194,15 @@ 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 3b30c0752274f..22230cc15dcd1 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 3f153f9e0ac59..2fd7702c67096 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 fadd2c907222b..e027933755989 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 e5ca3cf1a9496..ed53279d1106c 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 0b64e7f64e68c..8226b4da43507 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -734,8 +734,7 @@ 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); From 04cee82e04d2aff3d177ef0021ecdff228daf7b8 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:02:36 -0700 Subject: [PATCH 5/5] iommu: Propagate return value in ->attach_dev callback functions The mtk_iommu and virtio drivers have places in the ->attach_dev callback functions that return hardcode errnos instead of the returned values, but callers of these ->attach_dv callback functions may care. Propagate them directly without the extra conversions. Link: https://lore.kernel.org/r/ca8c5a447b87002334f83325f28823008b4ce420.1666042873.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Jean-Philippe Brucker Reviewed-by: Jason Gunthorpe Reviewed-by: Yong Wu Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/mtk_iommu.c | 2 +- drivers/iommu/virtio-iommu.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index eda441d0c6b68..b383c8327f9cb 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -668,7 +668,7 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain, ret = mtk_iommu_domain_finalise(dom, frstdata, region_id); if (ret) { mutex_unlock(&dom->mutex); - return -ENODEV; + return ret; } dom->bank = &data->bank[bankid]; } diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 8226b4da43507..5b8fe9bfa9a5b 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -697,7 +697,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev, if (ret) { ida_free(&viommu->domain_ids, vdomain->id); vdomain->viommu = NULL; - return -EOPNOTSUPP; + return ret; } }