diff options
authorDave Hansen <>2017-11-10 16:12:28 -0800
committerIngo Molnar <>2017-11-21 09:34:52 +0100
commitc51ff2c7fc45da8b18b28c4f15eca5a9975dfb59 (patch)
parentfd11a6496e12848d4eeb21029c2c288bbc638048 (diff)
x86/pkeys: Update documentation about availability
Now that CPUs that implement Memory Protection Keys are publicly available we can be a bit less oblique about where it is available. Signed-off-by: Dave Hansen <> Acked-by: Thomas Gleixner <> Cc: Andy Lutomirski <> Cc: Borislav Petkov <> Cc: Brian Gerst <> Cc: Denys Vlasenko <> Cc: H. Peter Anvin <> Cc: Josh Poimboeuf <> Cc: Linus Torvalds <> Cc: Peter Zijlstra <> Link: Signed-off-by: Ingo Molnar <>
1 files changed, 7 insertions, 2 deletions
diff --git a/Documentation/x86/protection-keys.txt b/Documentation/x86/protection-keys.txt
index fa46dcb347bc..ecb0d2dadfb7 100644
--- a/Documentation/x86/protection-keys.txt
+++ b/Documentation/x86/protection-keys.txt
@@ -1,5 +1,10 @@
-Memory Protection Keys for Userspace (PKU aka PKEYs) is a CPU feature
-which will be found on future Intel CPUs.
+Memory Protection Keys for Userspace (PKU aka PKEYs) is a feature
+which is found on Intel's Skylake "Scalable Processor" Server CPUs.
+It will be avalable in future non-server parts.
+For anyone wishing to test or use this feature, it is available in
+Amazon's EC2 C5 instances and is known to work there using an Ubuntu
+17.04 image.
Memory Protection Keys provides a mechanism for enforcing page-based
protections, but without requiring modification of the page tables