diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2017-07-17 16:10:01 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-18 11:37:59 +0200 |
| commit | 872cbefd2d9c52bd0b1e2c7942c4369e98a5a5ae (patch) | |
| tree | 0b29278590133584a9c0d6fba8f9e90fd83e787f /arch/x86/kernel/cpu/amd.c | |
| parent | f7750a79568788473c5e8092ee58a52248f34329 (diff) | |
x86/cpu/AMD: Add the Secure Memory Encryption CPU feature
Update the CPU features to include identifying and reporting on the
Secure Memory Encryption (SME) feature. SME is identified by CPUID
0x8000001f, but requires BIOS support to enable it (set bit 23 of
MSR_K8_SYSCFG). Only show the SME feature as available if reported by
CPUID, enabled by BIOS and not configured as CONFIG_X86_32=y.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/85c17ff450721abccddc95e611ae8df3f4d9718b.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/amd.c')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index bb5abe8f5fd4..5ccc7b2e63bb 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -611,6 +611,25 @@ static void early_init_amd(struct cpuinfo_x86 *c) */ if (cpu_has_amd_erratum(c, amd_erratum_400)) set_cpu_bug(c, X86_BUG_AMD_E400); + + /* + * BIOS support is required for SME. If BIOS has not enabled SME + * then don't advertise the feature (set in scattered.c). Also, + * since the SME support requires long mode, don't advertise the + * feature under CONFIG_X86_32. + */ + if (cpu_has(c, X86_FEATURE_SME)) { + if (IS_ENABLED(CONFIG_X86_32)) { + clear_cpu_cap(c, X86_FEATURE_SME); + } else { + u64 msr; + + /* Check if SME is enabled */ + rdmsrl(MSR_K8_SYSCFG, msr); + if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT)) + clear_cpu_cap(c, X86_FEATURE_SME); + } + } } static void init_amd_k8(struct cpuinfo_x86 *c) |