From 0aa48468d00959c8a37cd3ac727284f4f7359151 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Mon, 21 May 2018 17:54:49 -0400 Subject: KVM/VMX: Expose SSBD properly to guests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The X86_FEATURE_SSBD is an synthetic CPU feature - that is it bit location has no relevance to the real CPUID 0x7.EBX[31] bit position. For that we need the new CPU feature name. Fixes: 52817587e706 ("x86/cpufeatures: Disentangle SSBD enumeration") Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Thomas Gleixner Cc: kvm@vger.kernel.org Cc: "Radim Krčmář" Cc: stable@vger.kernel.org Cc: "H. Peter Anvin" Cc: Paolo Bonzini Link: https://lkml.kernel.org/r/20180521215449.26423-2-konrad.wilk@oracle.com --- arch/x86/kvm/cpuid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index ced851169730..598461e24be3 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -407,8 +407,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = - F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(SSBD) | - F(ARCH_CAPABILITIES); + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | + F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); -- cgit v1.2.3 From 8ecc4979b1bd9c94168e6fc92960033b7a951336 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 22 May 2018 11:05:39 +0200 Subject: x86/speculation: Simplify the CPU bug detection logic Only CPUs which speculate can speculate. Therefore, it seems prudent to test for cpu_no_speculation first and only then determine whether a specific speculating CPU is susceptible to store bypass speculation. This is underlined by all CPUs currently listed in cpu_no_speculation were present in cpu_no_spec_store_bypass as well. Signed-off-by: Dominik Brodowski Signed-off-by: Thomas Gleixner Cc: bp@suse.de Cc: konrad.wilk@oracle.com Link: https://lkml.kernel.org/r/20180522090539.GA24668@light.dominikbrodowski.net --- arch/x86/kernel/cpu/common.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 78decc3e3067..38276f58d3bf 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -942,12 +942,8 @@ static const __initconst struct x86_cpu_id cpu_no_meltdown[] = { {} }; +/* Only list CPUs which speculate but are non susceptible to SSB */ static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = { - { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PINEVIEW }, - { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT }, - { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL }, - { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW }, - { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT1 }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT2 }, @@ -955,14 +951,10 @@ static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = { { X86_VENDOR_INTEL, 6, INTEL_FAM6_CORE_YONAH }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM }, - { X86_VENDOR_CENTAUR, 5, }, - { X86_VENDOR_INTEL, 5, }, - { X86_VENDOR_NSC, 5, }, { X86_VENDOR_AMD, 0x12, }, { X86_VENDOR_AMD, 0x11, }, { X86_VENDOR_AMD, 0x10, }, { X86_VENDOR_AMD, 0xf, }, - { X86_VENDOR_ANY, 4, }, {} }; @@ -970,6 +962,12 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) { u64 ia32_cap = 0; + if (x86_match_cpu(cpu_no_speculation)) + return; + + setup_force_cpu_bug(X86_BUG_SPECTRE_V1); + setup_force_cpu_bug(X86_BUG_SPECTRE_V2); + if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES)) rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap); @@ -977,12 +975,6 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) !(ia32_cap & ARCH_CAP_SSB_NO)) setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS); - if (x86_match_cpu(cpu_no_speculation)) - return; - - setup_force_cpu_bug(X86_BUG_SPECTRE_V1); - setup_force_cpu_bug(X86_BUG_SPECTRE_V2); - if (x86_match_cpu(cpu_no_meltdown)) return; -- cgit v1.2.3