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authorLu Baolu <baolu.lu@linux.intel.com>2024-02-27 10:14:41 +0800
committerJoerg Roedel <jroedel@suse.de>2024-03-01 13:51:21 +0100
commitdef054b01a867822254e1dda13d587f5c7a99e2a (patch)
tree5d2c0eca919c6caa0e759d9dc93f79078e07d76a /drivers/iommu/intel/iommu.h
parent1a75cc710b956010137b4fe1d1fa3282bfd8f86c (diff)
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iommu/vt-d: Use device rbtree in iopf reporting path
The existing I/O page fault handler currently locates the PCI device by calling pci_get_domain_bus_and_slot(). This function searches the list of all PCI devices until the desired device is found. To improve lookup efficiency, replace it with device_rbtree_find() to search the device within the probed device rbtree. The I/O page fault is initiated by the device, which does not have any synchronization mechanism with the software to ensure that the device stays in the probed device tree. Theoretically, a device could be released by the IOMMU subsystem after device_rbtree_find() and before iopf_get_dev_fault_param(), which would cause a use-after-free problem. Add a mutex to synchronize the I/O page fault reporting path and the IOMMU release device path. This lock doesn't introduce any performance overhead, as the conflict between I/O page fault reporting and device releasing is very rare. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20240220065939.121116-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/intel/iommu.h')
-rw-r--r--drivers/iommu/intel/iommu.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 50d1e196db52..a0feab099f12 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -713,6 +713,8 @@ struct intel_iommu {
#endif
struct iopf_queue *iopf_queue;
unsigned char iopfq_name[16];
+ /* Synchronization between fault report and iommu device release. */
+ struct mutex iopf_lock;
struct q_inval *qi; /* Queued invalidation info */
u32 iommu_state[MAX_SR_DMAR_REGS]; /* Store iommu states between suspend and resume.*/