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iommu/vt-d: Fix NULL domain on device release

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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: 586081d3f6 ("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>
This commit is contained in:
Lu Baolu 2024-03-05 20:21:18 +08:00 committed by Joerg Roedel
parent 0061ffe289
commit 81e921fd32
3 changed files with 71 additions and 25 deletions
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31
drivers/iommu/intel/iommu.c
View File

@ -3818,30 +3818,6 @@ 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
@ -4367,7 +4343,11 @@ 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);
@ -4826,6 +4806,7 @@ 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,

64
drivers/iommu/intel/pasid.c
View File

@ -669,3 +669,67 @@ 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);
}

1
drivers/iommu/intel/pasid.h
View File

@ -319,4 +319,5 @@ 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 */