From: Lu Baolu baolu.lu@linux.intel.com
[ Upstream commit 81e921fd321614c2ad8ac333b041aae1da7a1c6d ]
In the kdump kernel, the IOMMU operates in deferred_attach mode. In this mode, info->domain may not yet be assigned by the time the release_device function is called. It leads to the following crash in the crash kernel:
BUG: kernel NULL pointer dereference, address: 000000000000003c ... RIP: 0010:do_raw_spin_lock+0xa/0xa0 ... _raw_spin_lock_irqsave+0x1b/0x30 intel_iommu_release_device+0x96/0x170 iommu_deinit_device+0x39/0xf0 __iommu_group_remove_device+0xa0/0xd0 iommu_bus_notifier+0x55/0xb0 notifier_call_chain+0x5a/0xd0 blocking_notifier_call_chain+0x41/0x60 bus_notify+0x34/0x50 device_del+0x269/0x3d0 pci_remove_bus_device+0x77/0x100 p2sb_bar+0xae/0x1d0 ... i801_probe+0x423/0x740
Use the release_domain mechanism to fix it. The scalable mode context entry which is not part of release domain should be cleared in release_device().
Fixes: 586081d3f6b1 ("iommu/vt-d: Remove DEFER_DEVICE_DOMAIN_INFO") Reported-by: Eric Badger ebadger@purestorage.com Closes: https://lore.kernel.org/r/20240113181713.1817855-1-ebadger@purestorage.com Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Kevin Tian kevin.tian@intel.com Link: https://lore.kernel.org/r/20240305013305.204605-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/intel/iommu.c | 31 ++++-------------- drivers/iommu/intel/pasid.c | 64 +++++++++++++++++++++++++++++++++++++ drivers/iommu/intel/pasid.h | 1 + 3 files changed, 71 insertions(+), 25 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 31b5d852ba732..5dba58f322f03 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -3874,30 +3874,6 @@ static void domain_context_clear(struct device_domain_info *info) &domain_context_clear_one_cb, info); }
-static void dmar_remove_one_dev_info(struct device *dev) -{ - struct device_domain_info *info = dev_iommu_priv_get(dev); - struct dmar_domain *domain = info->domain; - struct intel_iommu *iommu = info->iommu; - unsigned long flags; - - if (!dev_is_real_dma_subdevice(info->dev)) { - if (dev_is_pci(info->dev) && sm_supported(iommu)) - intel_pasid_tear_down_entry(iommu, info->dev, - IOMMU_NO_PASID, false); - - iommu_disable_pci_caps(info); - domain_context_clear(info); - } - - spin_lock_irqsave(&domain->lock, flags); - list_del(&info->link); - spin_unlock_irqrestore(&domain->lock, flags); - - domain_detach_iommu(domain, iommu); - info->domain = NULL; -} - /* * Clear the page table pointer in context or pasid table entries so that * all DMA requests without PASID from the device are blocked. If the page @@ -4436,7 +4412,11 @@ static void intel_iommu_release_device(struct device *dev) mutex_lock(&iommu->iopf_lock); device_rbtree_remove(info); mutex_unlock(&iommu->iopf_lock); - dmar_remove_one_dev_info(dev); + + if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev) && + !context_copied(iommu, info->bus, info->devfn)) + intel_pasid_teardown_sm_context(dev); + intel_pasid_free_table(dev); intel_iommu_debugfs_remove_dev(info); kfree(info); @@ -4942,6 +4922,7 @@ static const struct iommu_dirty_ops intel_dirty_ops = {
const struct iommu_ops intel_iommu_ops = { .blocked_domain = &blocking_domain, + .release_domain = &blocking_domain, .capable = intel_iommu_capable, .hw_info = intel_iommu_hw_info, .domain_alloc = intel_iommu_domain_alloc, diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index 746c7abe2237d..a51e895d9a178 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -670,3 +670,67 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
return 0; } + +/* + * Interfaces to setup or teardown a pasid table to the scalable-mode + * context table entry: + */ + +static void device_pasid_table_teardown(struct device *dev, u8 bus, u8 devfn) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + struct intel_iommu *iommu = info->iommu; + struct context_entry *context; + + spin_lock(&iommu->lock); + context = iommu_context_addr(iommu, bus, devfn, false); + if (!context) { + spin_unlock(&iommu->lock); + return; + } + + context_clear_entry(context); + __iommu_flush_cache(iommu, context, sizeof(*context)); + spin_unlock(&iommu->lock); + + /* + * Cache invalidation for changes to a scalable-mode context table + * entry. + * + * Section 6.5.3.3 of the VT-d spec: + * - Device-selective context-cache invalidation; + * - Domain-selective PASID-cache invalidation to affected domains + * (can be skipped if all PASID entries were not-present); + * - Domain-selective IOTLB invalidation to affected domains; + * - Global Device-TLB invalidation to affected functions. + * + * The iommu has been parked in the blocking state. All domains have + * been detached from the device or PASID. The PASID and IOTLB caches + * have been invalidated during the domain detach path. + */ + iommu->flush.flush_context(iommu, 0, PCI_DEVID(bus, devfn), + DMA_CCMD_MASK_NOBIT, DMA_CCMD_DEVICE_INVL); + devtlb_invalidation_with_pasid(iommu, dev, IOMMU_NO_PASID); +} + +static int pci_pasid_table_teardown(struct pci_dev *pdev, u16 alias, void *data) +{ + struct device *dev = data; + + if (dev == &pdev->dev) + device_pasid_table_teardown(dev, PCI_BUS_NUM(alias), alias & 0xff); + + return 0; +} + +void intel_pasid_teardown_sm_context(struct device *dev) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + + if (!dev_is_pci(dev)) { + device_pasid_table_teardown(dev, info->bus, info->devfn); + return; + } + + pci_for_each_dma_alias(to_pci_dev(dev), pci_pasid_table_teardown, dev); +} diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h index 487ede039bdde..42fda97fd8516 100644 --- a/drivers/iommu/intel/pasid.h +++ b/drivers/iommu/intel/pasid.h @@ -318,4 +318,5 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, bool fault_ignore); void intel_pasid_setup_page_snoop_control(struct intel_iommu *iommu, struct device *dev, u32 pasid); +void intel_pasid_teardown_sm_context(struct device *dev); #endif /* __INTEL_PASID_H */