Commit-ID: 9af9b94068fb1ea3206a700fc222075966fbef14 Gitweb: http://git.kernel.org/tip/9af9b94068fb1ea3206a700fc222075966fbef14 Author: Tom Lendacky <[email protected]> AuthorDate: Mon, 17 Jul 2017 16:10:02 -0500 Committer: Ingo Molnar <[email protected]> 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 <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Reviewed-by: Borislav Petkov <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brijesh Singh <[email protected]> Cc: Dave Young <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: Larry Woodman <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Michael S. Tsirkin <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Radim Krčmář <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Toshimitsu Kani <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/593c037a3cad85ba92f3d061ffa7462e9ce3531d.1500319216.git.thomas.lenda...@amd.com Signed-off-by: Ingo Molnar <[email protected]> --- 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); } } }
