x86/tme: Detect if TME and MKTME is activated by BIOS

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IA32_TME_ACTIVATE MSR (0x982) can be used to check if BIOS has enabled
TME and MKTME. It includes which encryption policy/algorithm is selected
for TME or available for MKTME. For MKTME, the MSR also enumerates how
many KeyIDs are available.

We would need to exclude KeyID bits from physical address bits.
detect_tme() would adjust cpuinfo_x86::x86_phys_bits accordingly.

We have to do this even if we are not going to use KeyID bits
ourself. VM guests still have to know that these bits are not usable
for physical address.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kai Huang <kai.huang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180305162610.37510-3-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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Kirill A. Shutemov 2018-03-05 19:25:50 +03:00 • committed by Ingo Molnar

parent 3c76db70eb

commit cb06d8e3d0

1 changed files with 90 additions and 0 deletions

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arch/x86/kernel/cpu/intel.c

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