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x86/msr: Add MSR_MISC_FEATURE_ENABLES and RING3MWAIT bit 

Define new MSR MISC_FEATURE_ENABLES (0x140).

On supported CPUs if bit 1 of this MSR is set, then calling MONITOR and
MWAIT instructions outside of ring 0 will not cause invalid-opcode
exception.

The MSR MISC_FEATURE_ENABLES is not yet documented in the SDM. Here is the
relevant documentation:

Hex   Dec  Name                     Scope
140H  320  MISC_FEATURE_ENABLES     Thread
           0    Reserved
           1    If set to 1, the MONITOR and MWAIT instructions do not
                cause invalid-opcode exceptions when executed with CPL > 0
                or in virtual-8086 mode. If MWAIT is executed when CPL > 0
                or in virtual-8086 mode, and if EAX indicates a C-state
                other than C0 or C1, the instruction operates as if EAX
                indicated the C-state C1.
           63:2 Reserved

Signed-off-by: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Piotr.Luc@intel.com
Cc: dave.hansen@linux.intel.com
Link: http://lkml.kernel.org/r/1484918557-15481-2-git-send-email-grzegorz.andrejczuk@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Grzegorz Andrejczuk 2017-01-20 14:22:33 +01:00 committed by Thomas Gleixner
parent 06b35d93af
commit ae47eda905
1 changed files with 5 additions and 0 deletions
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5
arch/x86/include/asm/msr-index.h
View File

@ -543,6 +543,11 @@
#define MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE_BIT 39
#define MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE (1ULL << MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE_BIT)
/* MISC_FEATURE_ENABLES non-architectural features */
#define MSR_MISC_FEATURE_ENABLES 0x00000140
#define MSR_MISC_FEATURE_ENABLES_RING3MWAIT_BIT 1
#define MSR_IA32_TSC_DEADLINE 0x000006E0
/* P4/Xeon+ specific */