[PATCH v7 21/21] x86/clearcpuid: Change document for kernel option clearcpuid

[Fenghua Yu]

Since kernel option clearcpuid now supports multiple options and CPU
capability flags, the document needs to be changed.

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
 .../admin-guide/kernel-parameters.txt          | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 2b8ee90bb644..0cbeda6d7f16 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -563,17 +563,21 @@
 			loops can be debugged more effectively on production
 			systems.
 
-	clearcpuid=BITNUM [X86]
+	clearcpuid=BITNUM | FLAG [X86]
 			Disable CPUID feature X for the kernel. See
 			arch/x86/include/asm/cpufeatures.h for the valid bit
-			numbers. Note the Linux specific bits are not necessarily
+			numbers or /proc/cpuinfo for valid CPU flags.
+			Multiple options can be used to disable a few features.
+			This prevents the feature from being used by the
+			kernel or shown in /proc/cpuinfo or shown in CPUID
+			called directly by user programs.
+			A few notes:
+			- The Linux specific bits are not necessarily
 			stable over kernel options, but the vendor specific
 			ones should be.
-			Also note that user programs calling CPUID directly
-			or using the feature without checking anything
-			will still see it. This just prevents it from
-			being used by the kernel or shown in /proc/cpuinfo.
-			Also note the kernel might malfunction if you disable
+			- User programs using the feature without checking
+			anything will still use it.
+			- The kernel might malfunction if you disable
 			some critical bits.
 
 	cma=nn[MG]@[start[MG][-end[MG]]]
-- 
2.19.1