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Merge tag 'for-joerg' of git://git.kernel.org/pub/scm/linux/kernel/gi…
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…t/jgg/iommufd into core

iommu: Define EINVAL as device/domain incompatibility

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.

Link: https://lore.kernel.org/r/cover.1666042872.git.nicolinc@nvidia.com
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Joerg Roedel committed Nov 3, 2022
2 parents 757636e + 04cee82 commit 69e61ed
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Showing 16 changed files with 60 additions and 56 deletions.
12 changes: 2 additions & 10 deletions drivers/iommu/amd/iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down
11 changes: 1 addition & 10 deletions drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
Original file line number Diff line number Diff line change
Expand Up @@ -2433,23 +2433,14 @@ 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;
}
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3 changes: 0 additions & 3 deletions drivers/iommu/arm/arm-smmu/arm-smmu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}
Expand Down
7 changes: 1 addition & 6 deletions drivers/iommu/arm/arm-smmu/qcom_iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}
Expand Down
2 changes: 1 addition & 1 deletion drivers/iommu/fsl_pamu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down
4 changes: 2 additions & 2 deletions drivers/iommu/fsl_pamu_domain.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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;
}

Expand Down
10 changes: 3 additions & 7 deletions drivers/iommu/intel/iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -4196,19 +4196,15 @@ 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;

/*
Expand Down
6 changes: 4 additions & 2 deletions drivers/iommu/intel/pasid.c
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down
24 changes: 24 additions & 0 deletions drivers/iommu/iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -1976,6 +1976,18 @@ 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;
Expand Down Expand Up @@ -2102,6 +2114,18 @@ 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;
Expand Down
2 changes: 0 additions & 2 deletions drivers/iommu/ipmmu-vmsa.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down
4 changes: 2 additions & 2 deletions drivers/iommu/mtk_iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down Expand Up @@ -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];
}
Expand Down
6 changes: 3 additions & 3 deletions drivers/iommu/omap-iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -1464,15 +1464,15 @@ 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);

/* 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;
}

Expand Down
4 changes: 1 addition & 3 deletions drivers/iommu/sprd-iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down
2 changes: 1 addition & 1 deletion drivers/iommu/tegra-gart.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down
7 changes: 3 additions & 4 deletions drivers/iommu/virtio-iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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;
}
}

Expand Down Expand Up @@ -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);

Expand Down
12 changes: 12 additions & 0 deletions include/linux/iommu.h
Original file line number Diff line number Diff line change
Expand Up @@ -278,6 +278,18 @@ 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
* * <others> - treated as ENODEV by the caller. Use is discouraged
* @detach_dev: detach an iommu domain from a device
* @set_dev_pasid: set an iommu domain to a pasid of device
* @map: map a physically contiguous memory region to an iommu domain
Expand Down

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