Messages in this thread | | | Date | Fri, 24 May 2019 11:00:05 -0700 | From | Jacob Pan <> | Subject | Re: [PATCH 3/4] iommu: Introduce device fault report API |
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On Thu, 23 May 2019 19:56:54 +0100 Robin Murphy <robin.murphy@arm.com> wrote:
> On 23/05/2019 19:06, Jean-Philippe Brucker wrote: > > From: Jacob Pan <jacob.jun.pan@linux.intel.com> > > > > Traditionally, device specific faults are detected and handled > > within their own device drivers. When IOMMU is enabled, faults such > > as DMA related transactions are detected by IOMMU. There is no > > generic reporting mechanism to report faults back to the in-kernel > > device driver or the guest OS in case of assigned devices. > > > > This patch introduces a registration API for device specific fault > > handlers. This differs from the existing iommu_set_fault_handler/ > > report_iommu_fault infrastructures in several ways: > > - it allows to report more sophisticated fault events (both > > unrecoverable faults and page request faults) due to the nature > > of the iommu_fault struct > > - it is device specific and not domain specific. > > > > The current iommu_report_device_fault() implementation only handles > > the "shoot and forget" unrecoverable fault case. Handling of page > > request faults or stalled faults will come later. > > > > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > > Signed-off-by: Ashok Raj <ashok.raj@intel.com> > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > > Signed-off-by: Eric Auger <eric.auger@redhat.com> > > --- > > drivers/iommu/iommu.c | 127 > > ++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | > > 29 ++++++++++ 2 files changed, 156 insertions(+) > > > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > index 67ee6623f9b2..d546f7baa0d4 100644 > > --- a/drivers/iommu/iommu.c > > +++ b/drivers/iommu/iommu.c > > @@ -644,6 +644,13 @@ int iommu_group_add_device(struct iommu_group > > *group, struct device *dev) goto err_free_name; > > } > > > > + dev->iommu_param = kzalloc(sizeof(*dev->iommu_param), > > GFP_KERNEL); > > + if (!dev->iommu_param) { > > + ret = -ENOMEM; > > + goto err_free_name; > > + } > > + mutex_init(&dev->iommu_param->lock); > > + > > Note that this gets a bit tricky when we come to move to move the > fwspec/ops/etc. into iommu_param, since that data can have a longer > lifespan than the group association. I'd suggest moving this > management out to the iommu_{probe,release}_device() level from the > start, but maybe we're happy to come back and change things later as > necessary. > Agreed, I can't think of any downside of moving it earlier. > Robin. > > [...] > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu
[Jacob Pan]
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