Messages in this thread | | | Subject | Re: [PATCH v3 1/4] iommu: Check IOMMU_DEV_FEAT_AUX feature in aux api's | From | Lu Baolu <> | Date | Thu, 30 Jul 2020 09:46:50 +0800 |
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Hi Alex,
On 7/30/20 4:03 AM, Alex Williamson wrote: > On Tue, 14 Jul 2020 13:57:00 +0800 > Lu Baolu <baolu.lu@linux.intel.com> wrote: > >> The iommu aux-domain api's work only when IOMMU_DEV_FEAT_AUX is enabled >> for the device. Add this check to avoid misuse. > > Shouldn't this really be the IOMMU driver's responsibility to test? If > nothing else, iommu_dev_feature_enabled() needs to get the iommu_ops > from dev->bus->iommu_ops, which is presumably the same iommu_ops we're > then calling from domain->ops to attach/detach the device, so it'd be > more efficient for the IOMMU driver to error on devices that don't > support aux. Thanks,
Fair enough. The vendor iommu driver always knows the status of aux- domain support. So this check is duplicated. I will drop this patch.
Best regards, baolu
> > Alex > >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> --- >> drivers/iommu/iommu.c | 16 +++++++++------- >> 1 file changed, 9 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 1ed1e14a1f0c..e1fdd3531d65 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -2725,11 +2725,13 @@ EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled); >> */ >> int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev) >> { >> - int ret = -ENODEV; >> + int ret; >> >> - if (domain->ops->aux_attach_dev) >> - ret = domain->ops->aux_attach_dev(domain, dev); >> + if (!iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) || >> + !domain->ops->aux_attach_dev) >> + return -ENODEV; >> >> + ret = domain->ops->aux_attach_dev(domain, dev); >> if (!ret) >> trace_attach_device_to_domain(dev); >> >> @@ -2748,12 +2750,12 @@ EXPORT_SYMBOL_GPL(iommu_aux_detach_device); >> >> int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev) >> { >> - int ret = -ENODEV; >> + if (!iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) || >> + !domain->ops->aux_get_pasid) >> + return -ENODEV; >> >> - if (domain->ops->aux_get_pasid) >> - ret = domain->ops->aux_get_pasid(domain, dev); >> + return domain->ops->aux_get_pasid(domain, dev); >> >> - return ret; >> } >> EXPORT_SYMBOL_GPL(iommu_aux_get_pasid); >> >
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