2022-09-23 07:39:08

by Nicolin Chen

[permalink] [raw]
Subject: [PATCH v6 0/5] Define EINVAL as device/domain incompatibility

This series is to replace the previous EMEDIUMTYPE patch in a VFIO series:
https://lore.kernel.org/kvm/[email protected]/

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-v6

Changelog
v6:
* Added "Reviewed-by" from Jason to all the changes
* Added "Reviewed-by" from Yong to the mtk_iommu change
* Dropped the msm patch as it needs a bigger change to fix
v5: https://lore.kernel.org/linux-iommu/[email protected]/
* Updated kdocs to correct "attach" narratives
* Updated kdocs to be more concise and accurate
* Added "Reviewed-by" from Kevin to most of changes
* Added "Reviewed-by" from Baolu to the intel_iommu changes
* Added "Reviewed-by" from Jean to the virtio-iommu changes
v4: https://lore.kernel.org/linux-iommu/[email protected]/
* 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/[email protected]/
* 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/[email protected]/
* 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/[email protected]/

Thanks!

Nicolin Chen (5):
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 | 24 +++++++++++++++++++++
drivers/iommu/ipmmu-vmsa.c | 2 --
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 +++++++++++
16 files changed, 60 insertions(+), 56 deletions(-)

--
2.17.1


2022-09-23 07:39:21

by Nicolin Chen

[permalink] [raw]
Subject: [PATCH v6 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.

Suggested-by: Robin Murphy <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Suravee Suthikulpanit <[email protected]>
Reviewed-by: Vasant Hegde <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Nicolin Chen <[email protected]>
---
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 828672a46a3d..930d9946b9f7 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2135,21 +2135,13 @@ 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);

--
2.17.1

2022-09-23 07:39:39

by Nicolin Chen

[permalink] [raw]
Subject: [PATCH v6 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.

Reviewed-by: Jean-Philippe Brucker <[email protected]>
Reviewed-by: Lu Baolu <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Nicolin Chen <[email protected]>
---
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 31bc50e538a3..b1788b3d3b2d 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4181,19 +4181,15 @@ 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);

--
2.17.1

2022-09-23 07:39:56

by Nicolin Chen

[permalink] [raw]
Subject: [PATCH v6 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.

Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Jean-Philippe Brucker <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Yong Wu <[email protected]>
Signed-off-by: Nicolin Chen <[email protected]>
---
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 be1a7d1cc630..c30dc8f81778 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -666,7 +666,7 @@ 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 87128266b6e3..35de7b433b17 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -696,7 +696,7 @@ 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;
}
}

--
2.17.1

2022-09-23 07:47:16

by Nicolin Chen

[permalink] [raw]
Subject: [PATCH v6 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.

Reviewed-by: Jean-Philippe Brucker <[email protected]>
Reviewed-by: Lu Baolu <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Nicolin Chen <[email protected]>
---
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 0d03f837a5d4..2eb3211c8167 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 011f9ab7f743..b4a1c0f79c3e 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 c5e7e8b020a5..aff1a9caa496 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 7e363b1f24df..be1a7d1cc630 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -607,7 +607,7 @@ 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 d9cf2820c02e..447e40d55918 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 80151176ba12..4c652773fd6c 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -669,7 +669,7 @@ 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,
--
2.17.1

2022-09-26 14:50:33

by Joerg Roedel

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] Define EINVAL as device/domain incompatibility

Hi Nicolin,

On Fri, Sep 23, 2022 at 12:16:29AM -0700, Nicolin Chen wrote:
> This series is to replace the previous EMEDIUMTYPE patch in a VFIO series:
> https://lore.kernel.org/kvm/[email protected]/

\o/

> Nicolin Chen (5):
> 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

This looks good to me, but I'd like to have the SMMU people have a look
at patch 4. And I think it is too late for this to make it into 6.1, so
please re-send after 6.1-rc1 is out.

Thanks,

Joerg

2022-09-26 23:32:21

by Nicolin Chen

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] Define EINVAL as device/domain incompatibility

On Mon, Sep 26, 2022 at 02:23:05PM +0200, Joerg Roedel wrote:
> External email: Use caution opening links or attachments
>
>
> Hi Nicolin,
>
> On Fri, Sep 23, 2022 at 12:16:29AM -0700, Nicolin Chen wrote:
> > This series is to replace the previous EMEDIUMTYPE patch in a VFIO series:
> > https://lore.kernel.org/kvm/[email protected]/
>
> \o/
>
> > Nicolin Chen (5):
> > 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
>
> This looks good to me, but I'd like to have the SMMU people have a look
> at patch 4. And I think it is too late for this to make it into 6.1, so
> please re-send after 6.1-rc1 is out.

Robin has given review comments against the similar patch in the
EMEDIUMTYPE series, though it'd be nicer to have a Reviewed-by.

I will re-send them rebasing on v6.1rc1.

Thanks!
Nic