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authorZeng Chi <zengchi@kylinos.cn>2026-09-21 18:24:42 +0800
committerSean Christopherson <seanjc@google.com>2026-09-22 08:36:16 -0700
commit119e9db233ad0f4cbd4cfb9f9385a7bca378b37d (patch)
tree660d50d4139cb750fbde1ae3432452c20726c99d /Documentation/ABI/testing/debugfs-tpmi
downloadlinux-stable-119e9db233ad0f4cbd4cfb9f9385a7bca378b37d.tar.gz
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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>
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+What: /sys/kernel/debug/tpmi-<n>/pfs_dump
+Date: November 2023
+KernelVersion: 6.6
+Contact: srinivas.pandruvada@linux.intel.com
+Description:
+The PFS (PM Feature Structure) table, shows details of each power
+management feature. This includes:
+tpmi_id, number of entries, entry size, offset, vsec offset, lock status
+and disabled status.
+Users: Debugging, any user space test suite
+
+What: /sys/kernel/debug/tpmi-<n>/tpmi-id-<n>/mem_dump
+Date: November 2023
+KernelVersion: 6.6
+Contact: srinivas.pandruvada@linux.intel.com
+Description:
+Shows the memory dump of the MMIO region for a TPMI ID.
+Users: Debugging, any user space test suite
+
+What: /sys/kernel/debug/tpmi-<n>/tpmi-id-<n>/mem_write
+Date: November 2023
+KernelVersion: 6.6
+Contact: srinivas.pandruvada@linux.intel.com
+Description:
+Allows to write at any offset. It doesn't check for Read/Write access
+as hardware will not allow to write at read-only memory. This write is
+at offset multiples of 4. The format is instance,offset,contents.
+Example:
+echo 0,0x20,0xff > mem_write
+echo 1,64,64 > mem_write
+Users: Debugging, any user space test suite
+
+What: /sys/kernel/debug/tpmi-<n>/plr/domain<n>/status
+Date: Aug 2024
+KernelVersion: 6.11
+Contact: Tero Kristo <tero.kristo@linux.intel.com>
+Description:
+Shows the currently active Performance Limit Reasons for die level and the
+individual CPUs under the die. The contents of this file are sticky, and
+clearing all the statuses can be done by writing "0\n" to this file.