Messages in this thread | | | Date | Sun, 24 Jul 2022 22:04:50 +0800 | Subject | Re: [PATCH v10 10/12] iommu: Prepare IOMMU domain for IOPF | From | Baolu Lu <> |
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On 2022/7/23 22:33, Jason Gunthorpe wrote: > On Tue, Jul 05, 2022 at 01:07:08PM +0800, Lu Baolu wrote: >> This adds some mechanisms around the iommu_domain so that the I/O page >> fault handling framework could route a page fault to the domain and >> call the fault handler from it. >> >> Add pointers to the page fault handler and its private data in struct >> iommu_domain. The fault handler will be called with the private data >> as a parameter once a page fault is routed to the domain. Any kernel >> component which owns an iommu domain could install handler and its >> private parameter so that the page fault could be further routed and >> handled. >> >> This also prepares the SVA implementation to be the first consumer of >> the per-domain page fault handling model. The I/O page fault handler >> for SVA is copied to the SVA file with mmget_not_zero() added before >> mmap_read_lock(). >> >> Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org> >> Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org> >> Tested-by: Tony Zhu <tony.zhu@intel.com> >> --- >> include/linux/iommu.h | 3 ++ >> drivers/iommu/iommu-sva-lib.h | 8 +++++ >> drivers/iommu/io-pgfault.c | 7 +++++ >> drivers/iommu/iommu-sva-lib.c | 58 +++++++++++++++++++++++++++++++++++ >> drivers/iommu/iommu.c | 4 +++ >> 5 files changed, 80 insertions(+) >> >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index ae0cfca064e6..47610f21d451 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -105,6 +105,9 @@ struct iommu_domain { >> unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */ >> struct iommu_domain_geometry geometry; >> struct iommu_dma_cookie *iova_cookie; >> + enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault, >> + void *data); >> + void *fault_data; >> union { >> struct { >> iommu_fault_handler_t handler; > > Why do we need two falut callbacks? The only difference is that one is > recoverable and the other is not, right? > > Can we run both down the same op?
The iommu_fault_handler_t is for report_iommu_fault() which could be replaced with the newer iommu_report_device_fault().
https://lore.kernel.org/linux-iommu/Yo4Nw9QyllT1RZbd@myrica/
> >> +/* >> + * I/O page fault handler for SVA >> + */ >> +enum iommu_page_response_code >> +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) >> +{ >> + vm_fault_t ret; >> + struct vm_area_struct *vma; >> + struct mm_struct *mm = data; >> + unsigned int access_flags = 0; >> + unsigned int fault_flags = FAULT_FLAG_REMOTE; >> + struct iommu_fault_page_request *prm = &fault->prm; >> + enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; >> + >> + if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) >> + return status; >> + >> + if (IS_ERR_OR_NULL(mm) || !mmget_not_zero(mm)) > > Do not use IS_ERR_ON_NULL. mm should never be null here since the > fault handler should have been removed from the domain before the > fault_data is changed.
Yes. Updated.
Best regards, baolu
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