Messages in this thread Patch in this message | | | Subject | Re: [PATCH v4 4/8] iommu/vt-d: Attach/detach domains in auxiliary mode | From | Lu Baolu <> | Date | Mon, 26 Nov 2018 10:37:02 +0800 |
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Hi,
On 11/23/18 6:49 PM, Auger Eric wrote: > Hi Lu, > > On 11/5/18 8:34 AM, Lu Baolu wrote: >> When multiple domains per device has been enabled by the >> device driver, the device will tag the default PASID for >> the domain to all DMA traffics out of the subset of this >> device; and the IOMMU should translate the DMA requests >> in PASID granularity. >> >> This extends the intel_iommu_attach/detach_device() ops >> to support managing PASID granular translation structures >> when the device driver has enabled multiple domains per >> device. >> >> Cc: Ashok Raj <ashok.raj@intel.com> >> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> >> Cc: Kevin Tian <kevin.tian@intel.com> >> Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> Signed-off-by: Liu Yi L <yi.l.liu@intel.com> >> --- >> drivers/iommu/intel-iommu.c | 192 +++++++++++++++++++++++++++++++----- >> include/linux/intel-iommu.h | 10 ++ >> 2 files changed, 180 insertions(+), 22 deletions(-) >> >> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c >> index 2c86ac71c774..a61b25ad0d3b 100644 >> --- a/drivers/iommu/intel-iommu.c >> +++ b/drivers/iommu/intel-iommu.c >> @@ -2477,6 +2477,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, >> info->iommu = iommu; >> info->pasid_table = NULL; >> info->auxd_enabled = 0; >> + INIT_LIST_HEAD(&info->auxiliary_domains); >> >> if (dev && dev_is_pci(dev)) { >> struct pci_dev *pdev = to_pci_dev(info->dev); >> @@ -5010,35 +5011,134 @@ static void intel_iommu_domain_free(struct iommu_domain *domain) >> domain_exit(to_dmar_domain(domain)); >> } >> >> -static int intel_iommu_attach_device(struct iommu_domain *domain, >> - struct device *dev) >> +/* >> + * Check whether a @domain will be attached to the @dev in the >> + * auxiliary mode. >> + */ >> +static inline bool >> +is_device_attach_aux_domain(struct device *dev, struct iommu_domain *domain) >> { >> - struct dmar_domain *dmar_domain = to_dmar_domain(domain); >> - struct intel_iommu *iommu; >> - int addr_width; >> - u8 bus, devfn; >> + struct device_domain_info *info = dev->archdata.iommu; >> >> - if (device_is_rmrr_locked(dev)) { >> - dev_warn(dev, "Device is ineligible for IOMMU domain attach due to platform RMRR requirement. Contact your platform vendor.\n"); >> - return -EPERM; >> - } >> + return info && info->auxd_enabled && >> + domain->type == IOMMU_DOMAIN_UNMANAGED; >> +} >> >> - /* normally dev is not mapped */ >> - if (unlikely(domain_context_mapped(dev))) { >> - struct dmar_domain *old_domain; >> +static void auxiliary_link_device(struct dmar_domain *domain, >> + struct device *dev) >> +{ >> + struct device_domain_info *info = dev->archdata.iommu; >> >> - old_domain = find_domain(dev); >> - if (old_domain) { >> - rcu_read_lock(); >> - dmar_remove_one_dev_info(old_domain, dev); >> - rcu_read_unlock(); >> + assert_spin_locked(&device_domain_lock); >> + if (WARN_ON(!info)) >> + return; >> >> - if (!domain_type_is_vm_or_si(old_domain) && >> - list_empty(&old_domain->devices)) >> - domain_exit(old_domain); >> + domain->auxd_refcnt++; >> + list_add(&domain->auxd, &info->auxiliary_domains); >> +} >> + >> +static void auxiliary_unlink_device(struct dmar_domain *domain, >> + struct device *dev) >> +{ >> + struct device_domain_info *info = dev->archdata.iommu; >> + >> + assert_spin_locked(&device_domain_lock); >> + if (WARN_ON(!info)) >> + return; >> + >> + list_del(&domain->auxd); >> + domain->auxd_refcnt--; >> + >> + if (!domain->auxd_refcnt && domain->default_pasid > 0) >> + intel_pasid_free_id(domain->default_pasid); >> +} >> + >> +static int domain_add_dev_auxd(struct dmar_domain *domain, >> + struct device *dev) >> +{ >> + int ret; >> + u8 bus, devfn; >> + unsigned long flags; >> + struct intel_iommu *iommu; >> + >> + iommu = device_to_iommu(dev, &bus, &devfn); >> + if (!iommu) >> + return -ENODEV; >> + >> + spin_lock_irqsave(&device_domain_lock, flags); >> + if (domain->default_pasid <= 0) { >> + domain->default_pasid = intel_pasid_alloc_id(domain, PASID_MIN, >> + pci_max_pasids(to_pci_dev(dev)), GFP_ATOMIC); >> + if (domain->default_pasid < 0) { >> + pr_err("Can't allocate default pasid\n"); >> + ret = -ENODEV; >> + goto pasid_failed; >> } >> } >> >> + spin_lock(&iommu->lock); > You may comment your nested lock policy somewhere.
Yes. I will add below comments.
/* * iommu->lock must be held to attach domain to iommu and setup the * pasid entry for second level translation. */
>> + ret = domain_attach_iommu(domain, iommu); >> + if (ret) >> + goto attach_failed; >> + >> + /* Setup the PASID entry for mediated devices: */ >> + ret = intel_pasid_setup_second_level(iommu, domain, dev, >> + domain->default_pasid); >> + if (ret) >> + goto table_failed; >> + spin_unlock(&iommu->lock); >> + >> + auxiliary_link_device(domain, dev); >> + >> + spin_unlock_irqrestore(&device_domain_lock, flags); >> + >> + return 0; >> + >> +table_failed: >> + domain_detach_iommu(domain, iommu); >> +attach_failed: >> + spin_unlock(&iommu->lock); >> + if (!domain->auxd_refcnt && domain->default_pasid > 0) >> + intel_pasid_free_id(domain->default_pasid); >> +pasid_failed: >> + spin_unlock_irqrestore(&device_domain_lock, flags); >> + >> + return ret; >> +} >> + >> +static void domain_remove_dev_aux(struct dmar_domain *domain, >> + struct device *dev) >> +{ >> + struct device_domain_info *info; >> + struct intel_iommu *iommu; >> + unsigned long flags; >> + >> + if (!is_device_attach_aux_domain(dev, &domain->domain)) >> + return; >> + >> + spin_lock_irqsave(&device_domain_lock, flags); >> + info = dev->archdata.iommu; >> + iommu = info->iommu; >> + >> + intel_pasid_tear_down_entry(iommu, dev, domain->default_pasid); >> + >> + auxiliary_unlink_device(domain, dev); >> + >> + spin_lock(&iommu->lock); >> + domain_detach_iommu(domain, iommu); >> + spin_unlock(&iommu->lock); >> + >> + spin_unlock_irqrestore(&device_domain_lock, flags); >> +} >> + >> +static int __intel_iommu_attach_device(struct iommu_domain *domain, >> + struct device *dev) >> +{ > Maybe introducing __intel_iommu_attach_device in a patch prior to that > one would help the review.
Yes. Will use a separated patch to introduce this helper.
>> + struct dmar_domain *dmar_domain = to_dmar_domain(domain); >> + struct intel_iommu *iommu; >> + int addr_width; >> + u8 bus, devfn; >> + >> iommu = device_to_iommu(dev, &bus, &devfn); >> if (!iommu) >> return -ENODEV; >> @@ -5071,7 +5171,47 @@ static int intel_iommu_attach_device(struct iommu_domain *domain, >> dmar_domain->agaw--; >> } >> >> - return domain_add_dev_info(dmar_domain, dev); >> + if (is_device_attach_aux_domain(dev, domain)) >> + return domain_add_dev_auxd(dmar_domain, dev); > why not putting this directly into intel_iommu_attach_device_aux()? >> + else >> + return domain_add_dev_info(dmar_domain, dev); > and this into intel_iommu_attach_device() as > __intel_iommu_attach_device() is the common part now?
Good suggestion.
>> +} >> + >> +static int intel_iommu_attach_device(struct iommu_domain *domain, >> + struct device *dev) >> +{ >> + if (device_is_rmrr_locked(dev)) { >> + dev_warn(dev, "Device is ineligible for IOMMU domain attach due to platform RMRR requirement. Contact your platform vendor.\n"); >> + return -EPERM; >> + } > shouldn't we test this in the common part (ie. in > __intel_iommu_attach_device). Don't RMRR also impact aux domains ?
RMRR is only for Request ID based DMA translation. Aux domain uses pasid-granular translation, hence should not be impacted by RMRR.
Furthermore, as far as I know, RMRR only used for legacy devices and should never be used with modern devices.
>> + >> + if (is_device_attach_aux_domain(dev, domain)) >> + return -EPERM; >> + >> + /* normally dev is not mapped */ >> + if (unlikely(domain_context_mapped(dev))) { >> + struct dmar_domain *old_domain; >> + >> + old_domain = find_domain(dev); >> + if (old_domain) { >> + rcu_read_lock(); >> + dmar_remove_one_dev_info(old_domain, dev); >> + rcu_read_unlock(); >> + >> + if (!domain_type_is_vm_or_si(old_domain) && >> + list_empty(&old_domain->devices)) >> + domain_exit(old_domain); >> + } >> + } >> + >> + return __intel_iommu_attach_device(domain, dev); >> +} >> + >> +static int intel_iommu_attach_device_aux(struct iommu_domain *domain, >> + struct device *dev) >> +{ >> + return is_device_attach_aux_domain(dev, domain) ? >> + __intel_iommu_attach_device(domain, dev) : -EPERM; >> } >> >> static void intel_iommu_detach_device(struct iommu_domain *domain, >> @@ -5080,6 +5220,12 @@ static void intel_iommu_detach_device(struct iommu_domain *domain, >> dmar_remove_one_dev_info(to_dmar_domain(domain), dev); >> } >> >> +static void intel_iommu_detach_device_aux(struct iommu_domain *domain, >> + struct device *dev) >> +{ >> + domain_remove_dev_aux(to_dmar_domain(domain), dev); >> +} >> + >> static int intel_iommu_map(struct iommu_domain *domain, >> unsigned long iova, phys_addr_t hpa, >> size_t size, int iommu_prot) >> @@ -5436,6 +5582,8 @@ 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, >> + .attach_dev_aux = intel_iommu_attach_device_aux, >> + .detach_dev_aux = intel_iommu_detach_device_aux, >> .map = intel_iommu_map, >> .unmap = intel_iommu_unmap, >> .iova_to_phys = intel_iommu_iova_to_phys, >> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h >> index 6b198e13e75e..678c7fb05e74 100644 >> --- a/include/linux/intel-iommu.h >> +++ b/include/linux/intel-iommu.h >> @@ -473,9 +473,11 @@ struct dmar_domain { >> /* Domain ids per IOMMU. Use u16 since >> * domain ids are 16 bit wide according >> * to VT-d spec, section 9.3 */ >> + unsigned int auxd_refcnt; /* Refcount of auxiliary attaching */ >> >> bool has_iotlb_device; >> struct list_head devices; /* all devices' list */ >> + struct list_head auxd; /* link to device's auxiliary list */ >> struct iova_domain iovad; /* iova's that belong to this domain */ >> >> struct dma_pte *pgd; /* virtual address */ >> @@ -494,6 +496,11 @@ struct dmar_domain { >> 2 == 1GiB, 3 == 512GiB, 4 == 1TiB */ >> u64 max_addr; /* maximum mapped address */ >> >> + int default_pasid; /* >> + * The default pasid used for non-SVM >> + * traffic on mediated devices. >> + */ >> + >> struct iommu_domain domain; /* generic domain data structure for >> iommu core */ >> }; >> @@ -543,6 +550,9 @@ struct device_domain_info { >> struct list_head link; /* link to domain siblings */ >> struct list_head global; /* link to global list */ >> struct list_head table; /* link to pasid table */ >> + struct list_head auxiliary_domains; /* auxiliary domains >> + * attached to this device >> + */ >> u8 bus; /* PCI bus number */ >> u8 devfn; /* PCI devfn number */ >> u16 pfsid; /* SRIOV physical function source ID */ >> > Thanks > > Eric >
Best regards, Lu Baolu
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