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| author | Zeng Chi <zengchi@kylinos.cn> | 2026-09-21 18:24:42 +0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-09-22 08:36:16 -0700 |
| commit | 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d (patch) | |
| tree | 660d50d4139cb750fbde1ae3432452c20726c99d /Documentation/ABI/testing/debugfs-amd-iommu | |
| download | linux-stable-119e9db233ad0f4cbd4cfb9f9385a7bca378b37d.tar.gz linux-stable-119e9db233ad0f4cbd4cfb9f9385a7bca378b37d.zip | |
KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted
Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.
Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'Documentation/ABI/testing/debugfs-amd-iommu')
| -rw-r--r-- | Documentation/ABI/testing/debugfs-amd-iommu | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/debugfs-amd-iommu b/Documentation/ABI/testing/debugfs-amd-iommu new file mode 100644 index 000000000..5621a66aa --- /dev/null +++ b/Documentation/ABI/testing/debugfs-amd-iommu @@ -0,0 +1,131 @@ +What: /sys/kernel/debug/iommu/amd/iommu<x>/mmio +Date: January 2025 +Contact: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> +Description: + This file provides read/write access for user input. Users specify the + MMIO register offset for iommu<x>, and the file outputs the corresponding + MMIO register value of iommu<x> + + Example:: + + $ echo "0x18" > /sys/kernel/debug/iommu/amd/iommu00/mmio + $ cat /sys/kernel/debug/iommu/amd/iommu00/mmio + + Output:: + + Offset:0x18 Value:0x000c22000003f48d + +What: /sys/kernel/debug/iommu/amd/iommu<x>/capability +Date: January 2025 +Contact: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> +Description: + This file provides read/write access for user input. Users specify the + capability register offset for iommu<x>, and the file outputs the + corresponding capability register value of iommu<x>. + + Example:: + + $ echo "0x10" > /sys/kernel/debug/iommu/amd/iommu00/capability + $ cat /sys/kernel/debug/iommu/amd/iommu00/capability + + Output:: + + Offset:0x10 Value:0x00203040 + +What: /sys/kernel/debug/iommu/amd/iommu<x>/cmdbuf +Date: January 2025 +Contact: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> +Description: + This file is a read-only output file containing iommu<x> command + buffer entries. + + Examples:: + + $ cat /sys/kernel/debug/iommu/amd/iommu<x>/cmdbuf + + Output:: + + CMD Buffer Head Offset:339 Tail Offset:339 + 0: 00835001 10000001 00003c00 00000000 + 1: 00000000 30000005 fffff003 7fffffff + 2: 00835001 10000001 00003c01 00000000 + 3: 00000000 30000005 fffff003 7fffffff + 4: 00835001 10000001 00003c02 00000000 + 5: 00000000 30000005 fffff003 7fffffff + 6: 00835001 10000001 00003c03 00000000 + 7: 00000000 30000005 fffff003 7fffffff + 8: 00835001 10000001 00003c04 00000000 + 9: 00000000 30000005 fffff003 7fffffff + 10: 00835001 10000001 00003c05 00000000 + 11: 00000000 30000005 fffff003 7fffffff + [...] + +What: /sys/kernel/debug/iommu/amd/devid +Date: January 2025 +Contact: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> +Description: + This file provides read/write access for user input. Users specify the + device ID, which can be used to dump IOMMU data structures such as the + interrupt remapping table and device table. + + Example: + + 1. + :: + + $ echo 0000:01:00.0 > /sys/kernel/debug/iommu/amd/devid + $ cat /sys/kernel/debug/iommu/amd/devid + + Output:: + + 0000:01:00.0 + + 2. + :: + + $ echo 01:00.0 > /sys/kernel/debug/iommu/amd/devid + $ cat /sys/kernel/debug/iommu/amd/devid + + Output:: + + 0000:01:00.0 + +What: /sys/kernel/debug/iommu/amd/devtbl +Date: January 2025 +Contact: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> +Description: + This file is a read-only output file containing the device table entry + for the device ID provided in /sys/kernel/debug/iommu/amd/devid. + + Example:: + + $ cat /sys/kernel/debug/iommu/amd/devtbl + + Output:: + + DeviceId QWORD[3] QWORD[2] QWORD[1] QWORD[0] iommu + 0000:01:00.0 0000000000000000 20000001373b8013 0000000000000038 6000000114d7b603 iommu3 + +What: /sys/kernel/debug/iommu/amd/irqtbl +Date: January 2025 +Contact: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> +Description: + This file is a read-only output file containing valid IRT table entries + for the device ID provided in /sys/kernel/debug/iommu/amd/devid. + + Example:: + + $ cat /sys/kernel/debug/iommu/amd/irqtbl + + Output:: + + DeviceId 0000:01:00.0 + IRT[0000] 0000000000000020 0000000000000241 + IRT[0001] 0000000000000020 0000000000000841 + IRT[0002] 0000000000000020 0000000000002041 + IRT[0003] 0000000000000020 0000000000008041 + IRT[0004] 0000000000000020 0000000000020041 + IRT[0005] 0000000000000020 0000000000080041 + IRT[0006] 0000000000000020 0000000000200041 + IRT[0007] 0000000000000020 0000000000800041 + [...] |