Commit-ID: 9af9b94068fb1ea3206a700fc222075966fbef14 Gitweb: http://git.kernel.org/tip/9af9b94068fb1ea3206a700fc222075966fbef14 Author: Tom Lendacky <thomas.lenda...@amd.com> AuthorDate: Mon, 17 Jul 2017 16:10:02 -0500 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 18 Jul 2017 11:37:59 +0200
x86/cpu/AMD: Handle SME reduction in physical address size When System Memory Encryption (SME) is enabled, the physical address space is reduced. Adjust the x86_phys_bits value to reflect this reduction. Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com> Reviewed-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Borislav Petkov <b...@suse.de> Cc: Alexander Potapenko <gli...@google.com> Cc: Andrey Ryabinin <aryabi...@virtuozzo.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Arnd Bergmann <a...@arndb.de> Cc: Borislav Petkov <b...@alien8.de> Cc: Brijesh Singh <brijesh.si...@amd.com> Cc: Dave Young <dyo...@redhat.com> Cc: Dmitry Vyukov <dvyu...@google.com> Cc: Jonathan Corbet <cor...@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com> Cc: Larry Woodman <lwood...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Matt Fleming <m...@codeblueprint.co.uk> Cc: Michael S. Tsirkin <m...@redhat.com> Cc: Paolo Bonzini <pbonz...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Radim Krčmář <rkrc...@redhat.com> Cc: Rik van Riel <r...@redhat.com> Cc: Toshimitsu Kani <toshi.k...@hpe.com> Cc: kasan-...@googlegroups.com Cc: k...@vger.kernel.org Cc: linux-a...@vger.kernel.org Cc: linux-...@vger.kernel.org Cc: linux-...@vger.kernel.org Cc: linux...@kvack.org Link: http://lkml.kernel.org/r/593c037a3cad85ba92f3d061ffa7462e9ce3531d.1500319216.git.thomas.lenda...@amd.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/cpu/amd.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 5ccc7b2..4d87950 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -613,21 +613,23 @@ static void early_init_amd(struct cpuinfo_x86 *c) 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. + * BIOS support is required for SME. If BIOS has enabled SME then + * adjust x86_phys_bits by the SME physical address space reduction + * value. 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; + u64 msr; - /* Check if SME is enabled */ - rdmsrl(MSR_K8_SYSCFG, msr); - if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT)) + /* Check if SME is enabled */ + rdmsrl(MSR_K8_SYSCFG, msr); + if (msr & MSR_K8_SYSCFG_MEM_ENCRYPT) { + c->x86_phys_bits -= (cpuid_ebx(0x8000001f) >> 6) & 0x3f; + if (IS_ENABLED(CONFIG_X86_32)) clear_cpu_cap(c, X86_FEATURE_SME); + } else { + clear_cpu_cap(c, X86_FEATURE_SME); } } }
