Messages in this thread | | | Date | Fri, 23 Jun 2017 11:19:52 -0700 | From | Jacob Pan <> | Subject | Re: [RFC 2/9] iommu/vt-d: add bind_pasid_table function |
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On Thu, 22 Jun 2017 16:52:15 -0600 Alex Williamson <alex.williamson@redhat.com> wrote:
> On Wed, 14 Jun 2017 15:22:56 -0700 > Jacob Pan <jacob.jun.pan@linux.intel.com> wrote: > > > Add Intel VT-d ops to the generic iommu_bind_pasid_table API > > functions. > > > > The primary use case is for direct assignment of SVM capable > > device. Originated from emulated IOMMU in the guest, the request > > goes through many layers (e.g. VFIO). Upon calling host IOMMU > > driver, caller passes guest PASID table pointer (GPA) and size. > > > > Device context table entry is modified by Intel IOMMU specific > > bind_pasid_table function. This will turn on nesting mode and > > matching translation type. > > > > The unbind operation restores default context mapping. > > > > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > > Signed-off-by: Liu, Yi L <yi.l.liu@linux.intel.com> > > Signed-off-by: Ashok Raj <ashok.raj@intel.com> > > --- > > drivers/iommu/intel-iommu.c | 109 > > ++++++++++++++++++++++++++++++++++++++++++ > > include/linux/dma_remapping.h | 1 + 2 files changed, 110 > > insertions(+) > > > > diff --git a/drivers/iommu/intel-iommu.c > > b/drivers/iommu/intel-iommu.c index fc2765c..1d5d9ab9 100644 > > --- a/drivers/iommu/intel-iommu.c > > +++ b/drivers/iommu/intel-iommu.c > > @@ -5430,6 +5430,111 @@ struct intel_iommu > > *intel_svm_device_to_iommu(struct device *dev) > > return iommu; > > } > > + > > +static int intel_iommu_bind_pasid_table(struct iommu_domain > > *domain, > > + struct device *dev, struct pasid_table_info > > *pasidt_binfo) +{ > > + struct intel_iommu *iommu; > > + struct context_entry *context; > > + struct dmar_domain *dmar_domain = to_dmar_domain(domain); > > + struct device_domain_info *info; > > + struct pci_dev *pdev; > > + u8 bus, devfn; > > + u16 did, *sid; > > + int ret = 0; > > + unsigned long flags; > > + u64 ctx_lo; > > + > > + if (pasidt_binfo == NULL || pasidt_binfo->model != > > INTEL_IOMMU) { > > Clearly model cannot be used as a bit field so it would appear wrong > to limit ourselves to 32 possible models by using it that way. > agreed. > > + pr_warn("%s: Invalid bind request!\n", __func__); > > Let the callers deal with error reporting. > ditto. > > + return -EINVAL; > > + } > > + > > + iommu = device_to_iommu(dev, &bus, &devfn); > > + if (!iommu) > > + return -ENODEV; > > + > > + sid = (u16 *)&pasidt_binfo->opaque; > > Failed to check length. > ditto. > > > + /* > > + * check SID, if it is not correct, return success to > > allow looping > > + * through all devices within a group > > + */ > > + if (PCI_DEVID(bus, devfn) != *sid) > > + return 0; > > + > > + pdev = to_pci_dev(dev); > > Better test dev_is_pci() first! > good point. > > + info = dev->archdata.iommu; > > + if (!info || !info->pasid_supported) { > > + pr_err("PCI %04x:%02x:%02x.%d: has no PASID > > support\n", > > + pci_domain_nr(pdev->bus), bus, > > PCI_SLOT(devfn), > > + PCI_FUNC(devfn)); > > + ret = -EINVAL; > > + goto out; > > + } > > + > > + if (pasidt_binfo->size > intel_iommu_get_pts(iommu)) { > > + pr_err("Invalid gPASID table size %llu, host size > > %lu\n", > > + pasidt_binfo->size, > > + intel_iommu_get_pts(iommu)); > > + ret = -EINVAL; > > + goto out; > > + } > > Different errnos here would be more useful to code that handles the > return than these pr_err()s. > OK. > > + spin_lock_irqsave(&iommu->lock, flags); > > + context = iommu_context_addr(iommu, bus, devfn, 0); > > + if (!context || !context_present(context)) { > > + pr_warn("%s: ctx not present for bus devfn > > %x:%x\n", > > + __func__, bus, devfn); > > + spin_unlock_irqrestore(&iommu->lock, flags); > > + goto out; > > Return success?! > good catch, should fail. > > + } > > + /* Anticipate guest to use SVM and owns the first level */ > > + ctx_lo = context[0].lo; > > + ctx_lo |= CONTEXT_NESTE; > > + ctx_lo |= CONTEXT_PRS; > > + ctx_lo |= CONTEXT_PASIDE; > > + ctx_lo &= ~CONTEXT_TT_MASK; > > + ctx_lo |= CONTEXT_TT_DEV_IOTLB << 2; > > + context[0].lo = ctx_lo; > > + > > + /* Assign guest PASID table pointer and size */ > > + ctx_lo = (pasidt_binfo->ptr & VTD_PAGE_MASK) | > > pasidt_binfo->size; > > + context[1].lo = ctx_lo; > > + /* make sure context entry is updated before flushing */ > > + wmb(); > > + did = dmar_domain->iommu_did[iommu->seq_id]; > > + iommu->flush.flush_context(iommu, did, > > + (((u16)bus) << 8) | devfn, > > + DMA_CCMD_MASK_NOBIT, > > + DMA_CCMD_DEVICE_INVL); > > + iommu->flush.flush_iotlb(iommu, did, 0, 0, > > DMA_TLB_DSI_FLUSH); > > + spin_unlock_irqrestore(&iommu->lock, flags); > > + > > + > > +out: > > + return ret; > > +} > > + > > +static int intel_iommu_unbind_pasid_table(struct iommu_domain > > *domain, > > + struct device *dev) > > +{ > > + struct intel_iommu *iommu; > > + struct dmar_domain *dmar_domain = to_dmar_domain(domain); > > + u8 bus, devfn; > > + > > + iommu = device_to_iommu(dev, &bus, &devfn); > > + if (!iommu) > > + return -ENODEV; > > + /* > > + * REVISIT: we might want to clear the PASID table pointer > > + * as part of context clear operation. Currently, it leaves > > + * stale data but should be ignored by hardware since > > PASIDE > > + * is clear. > > + */ > > + /* ATS will be reenabled when remapping is restored */ > > + pci_disable_ats(to_pci_dev(dev)); > > dev_is_pci()? > good to check, even thought intel iommu supports PCI only. > > + domain_context_clear(iommu, dev); > > + return domain_context_mapping_one(dmar_domain, iommu, bus, > > devfn); +} > > #endif /* CONFIG_INTEL_IOMMU_SVM */ > > > > const struct iommu_ops intel_iommu_ops = { > > @@ -5438,6 +5543,10 @@ const struct iommu_ops intel_iommu_ops = { > > .domain_free = intel_iommu_domain_free, > > .attach_dev = intel_iommu_attach_device, > > .detach_dev = intel_iommu_detach_device, > > +#ifdef CONFIG_INTEL_IOMMU_SVM > > + .bind_pasid_table = intel_iommu_bind_pasid_table, > > + .unbind_pasid_table = > > intel_iommu_unbind_pasid_table, +#endif > > .map = intel_iommu_map, > > .unmap = intel_iommu_unmap, > > .map_sg = default_iommu_map_sg, > > diff --git a/include/linux/dma_remapping.h > > b/include/linux/dma_remapping.h index 9088407..85367b7 100644 > > --- a/include/linux/dma_remapping.h > > +++ b/include/linux/dma_remapping.h > > @@ -27,6 +27,7 @@ > > > > #define CONTEXT_DINVE (1ULL << 8) > > #define CONTEXT_PRS (1ULL << 9) > > +#define CONTEXT_NESTE (1ULL << 10) > > #define CONTEXT_PASIDE (1ULL << 11) > > > > struct intel_iommu;
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