Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH v9 04/11] iommu: Add sva iommu_domain support | Date | Tue, 28 Jun 2022 08:50:16 +0000 |
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> From: Baolu Lu <baolu.lu@linux.intel.com> > Sent: Tuesday, June 28, 2022 1:41 PM > > > >> struct iommu_domain { > >> unsigned type; > >> const struct iommu_domain_ops *ops; > >> unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */ > >> - iommu_fault_handler_t handler; > >> - void *handler_token; > >> struct iommu_domain_geometry geometry; > >> struct iommu_dma_cookie *iova_cookie; > >> + union { > >> + struct { /* IOMMU_DOMAIN_DMA */ > >> + iommu_fault_handler_t handler; > >> + void *handler_token; > >> + }; > > > > why is it DMA domain specific? What about unmanaged > > domain? Unrecoverable fault can happen on any type > > including SVA. Hence I think above should be domain type > > agnostic. > > The report_iommu_fault() should be replaced by the new > iommu_report_device_fault(). Jean has already started this work. > > https://lore.kernel.org/linux-iommu/Yo4Nw9QyllT1RZbd@myrica/ > > Currently this is only for DMA domains, hence Robin suggested to make it > exclude with the SVA domain things. > > https://lore.kernel.org/linux-iommu/f3170016-4d7f-e78e-db48- > 68305f683349@arm.com/
Then it's worthy a comment that those two fields are for some legacy fault reporting stuff and DMA type only.
> > > >> + > >> + mutex_lock(&group->mutex); > >> + curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, > >> GFP_KERNEL); > >> + if (curr) > >> + goto out_unlock; > > > > Need check xa_is_err(old). > > Either > > (1) old entry is a valid pointer, or
return -EBUSY in this case
> (2) xa_is_err(curr)
return xa_err(cur)
> > are failure cases. Hence, "curr == NULL" is the only check we need. Did > I miss anything? >
But now you always return -EBUSY for all kinds of xa errors.
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