Messages in this thread | | | Subject | Re: [PATCH v4 3/5] iommu/vt-d: Disable non-recoverable fault processing before unbind | From | Lu Baolu <> | Date | Fri, 8 May 2020 09:39:18 +0800 |
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On 5/8/20 12:55 AM, Jacob Pan wrote: > On Thu, 7 May 2020 08:55:32 +0800 > Lu Baolu <baolu.lu@linux.intel.com> wrote: > >> When a PASID is used for SVA by the device, it's possible that the >> PASID entry is cleared before the device flushes all ongoing DMA >> requests. The IOMMU should ignore the non-recoverable faults caused >> by these requests. > Perhaps be more specific, only untranslated requests causes UR.
Yes. Sure!
> >> Intel VT-d provides such function through the FPD >> bit of the PASID entry. This sets FPD bit when PASID entry is cleared >> in the mm notifier and clear it when the pasid is unbound. >> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> --- >> drivers/iommu/intel-iommu.c | 4 ++-- >> drivers/iommu/intel-pasid.c | 26 +++++++++++++++++++++----- >> drivers/iommu/intel-pasid.h | 3 ++- >> drivers/iommu/intel-svm.c | 9 ++++++--- >> 4 files changed, 31 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c >> index d1866c0905b1..7811422b5a68 100644 >> --- a/drivers/iommu/intel-iommu.c >> +++ b/drivers/iommu/intel-iommu.c >> @@ -5352,7 +5352,7 @@ static void __dmar_remove_one_dev_info(struct >> device_domain_info *info) if (info->dev) { >> if (dev_is_pci(info->dev) && sm_supported(iommu)) >> intel_pasid_tear_down_entry(iommu, info->dev, >> - PASID_RID2PASID); >> + PASID_RID2PASID, false); >> >> iommu_disable_dev_iotlb(info); >> domain_context_clear(iommu, info->dev); >> @@ -5587,7 +5587,7 @@ static void aux_domain_remove_dev(struct >> dmar_domain *domain, auxiliary_unlink_device(domain, dev); >> >> spin_lock(&iommu->lock); >> - intel_pasid_tear_down_entry(iommu, dev, >> domain->default_pasid); >> + intel_pasid_tear_down_entry(iommu, dev, >> domain->default_pasid, false); domain_detach_iommu(domain, iommu); >> spin_unlock(&iommu->lock); >> >> diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c >> index 7969e3dac2ad..11aef6c12972 100644 >> --- a/drivers/iommu/intel-pasid.c >> +++ b/drivers/iommu/intel-pasid.c >> @@ -292,7 +292,20 @@ static inline void pasid_clear_entry(struct >> pasid_entry *pe) WRITE_ONCE(pe->val[7], 0); >> } >> >> -static void intel_pasid_clear_entry(struct device *dev, int pasid) >> +static inline void pasid_clear_entry_with_fpd(struct pasid_entry *pe) >> +{ >> + WRITE_ONCE(pe->val[0], PASID_PTE_FPD); >> + WRITE_ONCE(pe->val[1], 0); >> + WRITE_ONCE(pe->val[2], 0); >> + WRITE_ONCE(pe->val[3], 0); >> + WRITE_ONCE(pe->val[4], 0); >> + WRITE_ONCE(pe->val[5], 0); >> + WRITE_ONCE(pe->val[6], 0); >> + WRITE_ONCE(pe->val[7], 0); >> +} >> + >> +static void >> +intel_pasid_clear_entry(struct device *dev, int pasid, bool >> pf_ignore) { >> struct pasid_entry *pe; >> >> @@ -300,7 +313,10 @@ static void intel_pasid_clear_entry(struct >> device *dev, int pasid) if (WARN_ON(!pe)) >> return; >> >> - pasid_clear_entry(pe); >> + if (pf_ignore) >> + pasid_clear_entry_with_fpd(pe); >> + else >> + pasid_clear_entry(pe); >> } >> >> static inline void pasid_set_bits(u64 *ptr, u64 mask, u64 bits) >> @@ -533,8 +549,8 @@ devtlb_invalidation_with_pasid(struct intel_iommu >> *iommu, qi_flush_dev_iotlb(iommu, sid, pfsid, qdep, 0, 64 - >> VTD_PAGE_SHIFT); } >> >> -void intel_pasid_tear_down_entry(struct intel_iommu *iommu, >> - struct device *dev, int pasid) >> +void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct >> device *dev, >> + int pasid, bool pf_ignore) >> { >> struct pasid_entry *pte; >> u16 did; >> @@ -544,7 +560,7 @@ void intel_pasid_tear_down_entry(struct >> intel_iommu *iommu, return; >> >> did = pasid_get_domain_id(pte); >> - intel_pasid_clear_entry(dev, pasid); >> + intel_pasid_clear_entry(dev, pasid, pf_ignore); >> >> if (!ecap_coherent(iommu->ecap)) >> clflush_cache_range(pte, sizeof(*pte)); >> diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h >> index a41b09b3ffde..e6dd95ffe381 100644 >> --- a/drivers/iommu/intel-pasid.h >> +++ b/drivers/iommu/intel-pasid.h >> @@ -15,6 +15,7 @@ >> #define PASID_MAX 0x100000 >> #define PASID_PTE_MASK 0x3F >> #define PASID_PTE_PRESENT 1 >> +#define PASID_PTE_FPD 2 >> #define PDE_PFN_MASK PAGE_MASK >> #define PASID_PDE_SHIFT 6 >> #define MAX_NR_PASID_BITS 20 >> @@ -120,7 +121,7 @@ int intel_pasid_setup_nested(struct intel_iommu >> *iommu, struct iommu_gpasid_bind_data_vtd *pasid_data, >> struct dmar_domain *domain, int >> addr_width); void intel_pasid_tear_down_entry(struct intel_iommu >> *iommu, >> - struct device *dev, int pasid); >> + struct device *dev, int pasid, bool >> pf_ignore); int vcmd_alloc_pasid(struct intel_iommu *iommu, unsigned >> int *pasid); void vcmd_free_pasid(struct intel_iommu *iommu, unsigned >> int pasid); #endif /* __INTEL_PASID_H */ >> diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c >> index 83dc4319f661..9561ba59a170 100644 >> --- a/drivers/iommu/intel-svm.c >> +++ b/drivers/iommu/intel-svm.c >> @@ -207,7 +207,8 @@ static void intel_mm_release(struct mmu_notifier >> *mn, struct mm_struct *mm) */ >> rcu_read_lock(); >> list_for_each_entry_rcu(sdev, &svm->devs, list) { >> - intel_pasid_tear_down_entry(svm->iommu, sdev->dev, >> svm->pasid); >> + intel_pasid_tear_down_entry(svm->iommu, sdev->dev, >> + svm->pasid, true); >> intel_flush_svm_range_dev(svm, sdev, 0, -1, 0); >> } >> rcu_read_unlock(); >> @@ -400,7 +401,8 @@ int intel_svm_unbind_gpasid(struct device *dev, >> int pasid) sdev->users--; >> if (!sdev->users) { >> list_del_rcu(&sdev->list); >> - intel_pasid_tear_down_entry(iommu, dev, >> svm->pasid); >> + intel_pasid_tear_down_entry(iommu, dev, >> + svm->pasid, >> false); intel_flush_svm_range_dev(svm, sdev, 0, -1, 0); >> /* TODO: Drain in flight PRQ for the PASID >> since it >> * may get reused soon, we don't want to >> @@ -643,7 +645,8 @@ int intel_svm_unbind_mm(struct device *dev, int >> pasid) >> * to use. We have a *shared* PASID table, >> because it's >> * large and has to be physically >> contiguous. So it's >> * hard to be as defensive as we might like. >> */ >> - intel_pasid_tear_down_entry(iommu, dev, >> svm->pasid); >> + intel_pasid_tear_down_entry(iommu, dev, >> + svm->pasid, >> false); intel_flush_svm_range_dev(svm, sdev, 0, -1, 0); >> kfree_rcu(sdev, rcu); >> > Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com> >
Best regards, baolu
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