In the existing code, loop all devices attached to a domain does not include sub-devices attached via iommu_aux_attach_device().
This was found by when I'm working on the belwo patch, There is no device in the domain->devices list, thus unable to get the cap and ecap of iommu unit. But this domain actually has subdevice which is attached via aux-manner. But it is tracked by domain. This patch is going to fix it. https://lore.kernel.org/kvm/1599734733-6431-17-git-send-email-yi.l....@intel.com/ And this fix goes beyond the patch above, such sub-device tracking is necessary for other cases. For example, flushing device_iotlb for a domain which has sub-devices attached by auxiliary manner. Co-developed-by: Xin Zeng <xin.z...@intel.com> Signed-off-by: Xin Zeng <xin.z...@intel.com> Signed-off-by: Liu Yi L <yi.l....@intel.com> --- drivers/iommu/intel/iommu.c | 95 +++++++++++++++++++++++++++---------- include/linux/intel-iommu.h | 16 +++++-- 2 files changed, 82 insertions(+), 29 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 788119c5b021..d7720a836268 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1877,6 +1877,7 @@ static struct dmar_domain *alloc_domain(int flags) domain->flags |= DOMAIN_FLAG_USE_FIRST_LEVEL; domain->has_iotlb_device = false; INIT_LIST_HEAD(&domain->devices); + INIT_LIST_HEAD(&domain->subdevices); return domain; } @@ -2547,7 +2548,7 @@ 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); + INIT_LIST_HEAD(&info->subdevices); if (dev && dev_is_pci(dev)) { struct pci_dev *pdev = to_pci_dev(info->dev); @@ -4475,33 +4476,61 @@ is_aux_domain(struct device *dev, struct iommu_domain *domain) domain->type == IOMMU_DOMAIN_UNMANAGED; } -static void auxiliary_link_device(struct dmar_domain *domain, - struct device *dev) +static inline struct subdev_domain_info * +lookup_subdev_info(struct dmar_domain *domain, struct device *dev) +{ + struct subdev_domain_info *sinfo; + + if (!list_empty(&domain->subdevices)) { + list_for_each_entry(sinfo, &domain->subdevices, link_domain) { + if (sinfo->pdev == dev) + return sinfo; + } + } + + return NULL; +} + +static int auxiliary_link_device(struct dmar_domain *domain, + struct device *dev) { struct device_domain_info *info = get_domain_info(dev); + struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev); assert_spin_locked(&device_domain_lock); if (WARN_ON(!info)) - return; + return -EINVAL; + + if (!sinfo) { + sinfo = kzalloc(sizeof(*sinfo), GFP_ATOMIC); + sinfo->domain = domain; + sinfo->pdev = dev; + list_add(&sinfo->link_phys, &info->subdevices); + list_add(&sinfo->link_domain, &domain->subdevices); + } - domain->auxd_refcnt++; - list_add(&domain->auxd, &info->auxiliary_domains); + return ++sinfo->users; } -static void auxiliary_unlink_device(struct dmar_domain *domain, - struct device *dev) +static int auxiliary_unlink_device(struct dmar_domain *domain, + struct device *dev) { struct device_domain_info *info = get_domain_info(dev); + struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev); + int ret; assert_spin_locked(&device_domain_lock); - if (WARN_ON(!info)) - return; + if (WARN_ON(!info || !sinfo || sinfo->users <= 0)) + return -EINVAL; - list_del(&domain->auxd); - domain->auxd_refcnt--; + ret = --sinfo->users; + if (!ret) { + list_del(&sinfo->link_phys); + list_del(&sinfo->link_domain); + kfree(sinfo); + } - if (!domain->auxd_refcnt && domain->default_pasid > 0) - ioasid_put(domain->default_pasid); + return ret; } static int aux_domain_add_dev(struct dmar_domain *domain, @@ -4530,6 +4559,19 @@ static int aux_domain_add_dev(struct dmar_domain *domain, } spin_lock_irqsave(&device_domain_lock, flags); + ret = auxiliary_link_device(domain, dev); + if (ret <= 0) + goto link_failed; + + /* + * Subdevices from the same physical device can be attached to the + * same domain. For such cases, only the first subdevice attachment + * needs to go through the full steps in this function. So if ret > + * 1, just goto out. + */ + if (ret > 1) + goto out; + /* * iommu->lock must be held to attach domain to iommu and setup the * pasid entry for second level translation. @@ -4548,10 +4590,9 @@ static int aux_domain_add_dev(struct dmar_domain *domain, domain->default_pasid); if (ret) goto table_failed; - spin_unlock(&iommu->lock); - - auxiliary_link_device(domain, dev); + spin_unlock(&iommu->lock); +out: spin_unlock_irqrestore(&device_domain_lock, flags); return 0; @@ -4560,8 +4601,10 @@ static int aux_domain_add_dev(struct dmar_domain *domain, domain_detach_iommu(domain, iommu); attach_failed: spin_unlock(&iommu->lock); + auxiliary_unlink_device(domain, dev); +link_failed: spin_unlock_irqrestore(&device_domain_lock, flags); - if (!domain->auxd_refcnt && domain->default_pasid > 0) + if (list_empty(&domain->subdevices) && domain->default_pasid > 0) ioasid_put(domain->default_pasid); return ret; @@ -4581,14 +4624,18 @@ static void aux_domain_remove_dev(struct dmar_domain *domain, info = get_domain_info(dev); iommu = info->iommu; - auxiliary_unlink_device(domain, dev); - - spin_lock(&iommu->lock); - intel_pasid_tear_down_entry(iommu, dev, domain->default_pasid, false); - domain_detach_iommu(domain, iommu); - spin_unlock(&iommu->lock); + if (!auxiliary_unlink_device(domain, dev)) { + spin_lock(&iommu->lock); + intel_pasid_tear_down_entry(iommu, dev, + domain->default_pasid, false); + domain_detach_iommu(domain, iommu); + spin_unlock(&iommu->lock); + } spin_unlock_irqrestore(&device_domain_lock, flags); + + if (list_empty(&domain->subdevices) && domain->default_pasid > 0) + ioasid_put(domain->default_pasid); } static int prepare_domain_attach_device(struct iommu_domain *domain, diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 94522685a0d9..09c6a0bf3892 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -533,11 +533,10 @@ 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 list_head subdevices; /* all subdevices' list */ struct iova_domain iovad; /* iova's that belong to this domain */ struct dma_pte *pgd; /* virtual address */ @@ -610,14 +609,21 @@ struct intel_iommu { struct dmar_drhd_unit *drhd; }; +/* Per subdevice private data */ +struct subdev_domain_info { + struct list_head link_phys; /* link to phys device siblings */ + struct list_head link_domain; /* link to domain siblings */ + struct device *pdev; /* physical device derived from */ + struct dmar_domain *domain; /* aux-domain */ + int users; /* user count */ +}; + /* PCI domain-device relationship */ 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 - */ + struct list_head subdevices; /* subdevices sibling */ u32 segment; /* PCI segment number */ u8 bus; /* PCI bus number */ u8 devfn; /* PCI devfn number */ -- 2.25.1
