Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH RFC 08/11] iommu: Handle IO page faults directly | Date | Tue, 22 Mar 2022 00:39:23 +0000 |
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> From: Jean-Philippe Brucker <jean-philippe@linaro.org> > Sent: Monday, March 21, 2022 7:36 PM > > On Sun, Mar 20, 2022 at 02:40:27PM +0800, Lu Baolu wrote: > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > index c0966fc9b686..4f90b71c6f6e 100644 > > --- a/drivers/iommu/iommu.c > > +++ b/drivers/iommu/iommu.c > > @@ -27,6 +27,8 @@ > > #include <linux/cc_platform.h> > > #include <trace/events/iommu.h> > > > > +#include "iommu-sva-lib.h" > > + > > static struct kset *iommu_group_kset; > > static DEFINE_IDA(iommu_group_ida); > > > > @@ -1177,10 +1179,9 @@ int iommu_report_device_fault(struct device > *dev, struct iommu_fault_event *evt) > > if (!param || !evt) > > return -EINVAL; > > > > - /* we only report device fault if there is a handler registered */ > > mutex_lock(¶m->lock); > > fparam = param->fault_param; > > - if (!fparam || !fparam->handler) { > > + if (!fparam) { > > ret = -EINVAL; > > goto done_unlock; > > } > > @@ -1198,7 +1199,11 @@ int iommu_report_device_fault(struct device > *dev, struct iommu_fault_event *evt) > > mutex_unlock(&fparam->lock); > > } > > > > - ret = fparam->handler(&evt->fault, fparam->data); > > + if (fparam->handler) > > + ret = fparam->handler(&evt->fault, fparam->data); > > + else > > + ret = iommu_queue_iopf(&evt->fault, fparam->data); > > + > > I like the change, but we'll need to consolidate this, because now if the > driver registers a fault handler it disables IOPF. We could instead > prevent registration if an IOPF param is present. We could also just merge > fparam->handler but eventually I'd like to make IOPF fall back to the > fault handler registered by device driver, in case of invalid page faults. > I have a couple patches for this but am still missing some bits. >
Probably we need two different fault reporting interfaces:
iommu_report_device_fault() iommu_report_domain_fault()
iommu driver knows the type of faults and just calls individual API accordingly. fallback is also managed by iommu driver if necessary.
Thanks Kevin
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