kernel/linux.git/drivers/iommu/intel/debugfs.c, branch v6.6.131

iommu/vt-d: Replace snprintf with scnprintf in dmar_latency_snapshot()

2025-11-24T09:29:41+00:00

[ Upstream commit 75c02a037609f34db17e91be195cedb33b61bae0 ] snprintf() returns the number of bytes that would have been written, not the number actually written. Using this for offset tracking can cause buffer overruns if truncation occurs. Replace snprintf() with scnprintf() to ensure the offset stays within bounds. Since scnprintf() never returns a negative value, and zero is not possible in this context because 'bytes' starts at 0 and 'size - bytes' is DEBUG_BUFFER_SIZE in the first call, which is large enough to hold the string literals used, the return value is always positive. An integer overflow is also completely out of reach here due to the small and fixed buffer size. The error check in latency_show_one() is therefore unnecessary. Remove it and make dmar_latency_snapshot() return void. Signed-off-by: Seyediman Seyedarab Link: https://lore.kernel.org/r/20250731225048.131364-1-ImanDevel@gmail.com Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/vt-d: Replace spin_lock_irqsave() with spin_lock()

2022-07-15T08:21:36+00:00

The iommu->lock is used to protect changes in root/context/pasid tables and domain ID allocation. There's no use case to change these resources in any interrupt context. Therefore, it is unnecessary to disable the interrupts when the spinlock is held. The same thing happens on the device_domain_lock side, which protects the device domain attachment information. This replaces spin_lock/unlock_irqsave/irqrestore() calls with the normal spin_lock/unlock(). Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220706025524.2904370-6-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: debugfs: Remove device_domain_lock usage

2022-07-15T08:21:33+00:00

The domain_translation_struct debugfs node is used to dump the DMAR page tables for the PCI devices. It potentially races with setting domains to devices. The existing code uses the global spinlock device_domain_lock to avoid the races. This removes the use of device_domain_lock outside of iommu.c by replacing it with the group mutex lock. Using the group mutex lock is cleaner and more compatible to following cleanups. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220706025524.2904370-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Move include/linux/intel-iommu.h under iommu

2022-07-15T08:21:31+00:00

This header file is private to the Intel IOMMU driver. Move it to the driver folder. Signed-off-by: Lu Baolu Reviewed-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Reviewed-by: Steve Wahl Link: https://lore.kernel.org/r/20220514014322.2927339-8-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Remove DEFER_DEVICE_DOMAIN_INFO

2022-03-04T15:46:30+00:00

Allocate and set the per-device iommu private data during iommu device probe. This makes the per-device iommu private data always available during iommu_probe_device() and iommu_release_device(). With this changed, the dummy DEFER_DEVICE_DOMAIN_INFO pointer could be removed. The wrappers for getting the private data and domain are also cleaned. Signed-off-by: Lu Baolu Reviewed-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20220214025704.3184654-1-baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20220301020159.633356-6-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Remove aux-domain related callbacks

2022-02-28T12:25:48+00:00

The aux-domain related callbacks are not called in the tree. Remove them to avoid dead code. Signed-off-by: Lu Baolu Reviewed-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20220216025249.3459465-4-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Expose latency monitor data through debugfs

2021-06-10T07:06:13+00:00

A debugfs interface /sys/kernel/debug/iommu/intel/dmar_perf_latency is created to control and show counts of execution time ranges for various types per DMAR. The interface may help debug any potential performance issue. By default, the interface is disabled. Possible write value of /sys/kernel/debug/iommu/intel/dmar_perf_latency 0 - disable sampling all latency data 1 - enable sampling IOTLB invalidation latency data 2 - enable sampling devTLB invalidation latency data 3 - enable sampling intr entry cache invalidation latency data 4 - enable sampling prq handling latency data Read /sys/kernel/debug/iommu/intel/dmar_perf_latency gives a snapshot of sampling result of all enabled monitors. Signed-off-by: Fenghua Yu Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20210610020115.1637656-15-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Rename intel-pasid.h to pasid.h

2020-07-24T08:51:21+00:00

As Intel VT-d files have been moved to its own subdirectory, the prefix makes no sense. No functional changes. Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20200724014925.15523-13-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Move Intel IOMMU driver into subdirectory

2020-06-10T15:46:43+00:00

Move all files related to the Intel IOMMU driver into its own subdirectory. Signed-off-by: Joerg Roedel Reviewed-by: Jerry Snitselaar Reviewed-by: Lu Baolu Link: https://lore.kernel.org/r/20200609130303.26974-3-joro@8bytes.org