Messages in this thread | | | Subject | Re: [PATCH v2 3/4] iommu/vt-d: Report page request faults for guest SVA | From | Lu Baolu <> | Date | Wed, 8 Jul 2020 10:13:02 +0800 |
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Hi Jean,
On 7/7/20 7:23 PM, Jean-Philippe Brucker wrote: > On Mon, Jul 06, 2020 at 08:25:34AM +0800, Lu Baolu wrote: >> A pasid might be bound to a page table from a VM guest via the iommu >> ops.sva_bind_gpasid. In this case, when a DMA page fault is detected >> on the physical IOMMU, we need to inject the page fault request into >> the guest. After the guest completes handling the page fault, a page >> response need to be sent back via the iommu ops.page_response(). >> >> This adds support to report a page request fault. Any external module >> which is interested in handling this fault should regiester a notifier >> callback. >> >> Co-developed-by: Jacob Pan <jacob.jun.pan@linux.intel.com> >> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> >> Co-developed-by: Liu Yi L <yi.l.liu@intel.com> >> Signed-off-by: Liu Yi L <yi.l.liu@intel.com> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> --- > [...] >> +static int >> +intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc) >> +{ >> + struct iommu_fault_event event; >> + u8 bus, devfn; >> + >> + memset(&event, 0, sizeof(struct iommu_fault_event)); >> + bus = PCI_BUS_NUM(desc->rid); >> + devfn = desc->rid & 0xff; >> + >> + /* Fill in event data for device specific processing */ >> + event.fault.type = IOMMU_FAULT_PAGE_REQ; >> + event.fault.prm.addr = desc->addr; >> + event.fault.prm.pasid = desc->pasid; >> + event.fault.prm.grpid = desc->prg_index; >> + event.fault.prm.perm = prq_to_iommu_prot(desc); >> + >> + /* >> + * Set last page in group bit if private data is present, >> + * page response is required as it does for LPIG. >> + */ >> + if (desc->lpig) >> + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE; >> + if (desc->pasid_present) >> + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID; > > Do you also need to set IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID? I added > the flag to deal with devices that do not want a PASID value in their PRI > response (bit 15 in the PCIe Page Request Status Register): > https://lore.kernel.org/linux-iommu/20200616144712.748818-1-jean-philippe@linaro.org/ > (applied by Joerg for v5.9) > > Grepping for pci_prg_resp_pasid_required() in intel/iommu.c it seems to > currently reject devices that do not want a PASID in a PRI response, so I > think you can set this flag unconditionally for now.
Yes. You are right. I will set this flag in the next version.
Best regards, baolu
> > Thanks, > Jean > >> + if (desc->priv_data_present) { >> + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE; >> + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA; >> + memcpy(event.fault.prm.private_data, desc->priv_data, >> + sizeof(desc->priv_data)); >> + } >> + >> + return iommu_report_device_fault(dev, &event); >> +}
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