summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/sysfs-amd-pmf
diff options
context:
space:
mode:
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/sysfs-amd-pmf
downloadlinux-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/sysfs-amd-pmf')
-rw-r--r--Documentation/ABI/testing/sysfs-amd-pmf13
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-amd-pmf b/Documentation/ABI/testing/sysfs-amd-pmf
new file mode 100644
index 000000000..7fc0e1c2b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-amd-pmf
@@ -0,0 +1,13 @@
+What: /sys/devices/platform/*/cnqf_enable
+Date: September 2022
+Contact: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+Description: Reading this file tells if the AMD Platform Management(PMF)
+ Cool n Quiet Framework(CnQF) feature is enabled or not.
+
+ This feature is not enabled by default and gets only turned on
+ if OEM BIOS passes a "flag" to PMF ACPI function (index 11 or 12)
+ or in case the user writes "on".
+
+ To turn off CnQF user can write "off" to the sysfs node.
+ Note: Systems that support auto mode will not have this sysfs file
+ available.