Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
authorLinus Torvalds <torvalds@linux-foundation.org>
Sat, 26 May 2018 20:24:16 +0000 (13:24 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 26 May 2018 20:24:16 +0000 (13:24 -0700)
Pull x86 store buffer fixes from Thomas Gleixner:
 "Two fixes for the SSBD mitigation code:

   - expose SSBD properly to guests. This got broken when the CPU
     feature flags got reshuffled.

   - simplify the CPU detection logic to avoid duplicate entries in the
     tables"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation: Simplify the CPU bug detection logic
  KVM/VMX: Expose SSBD properly to guests

arch/x86/kernel/cpu/common.c
arch/x86/kvm/cpuid.c

index 78decc3e306712dbca3ffd4c71392f681ba9f5df..38276f58d3bfe2ce17d51450360be69c5ab70e43 100644 (file)
@@ -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;
 
index 9bffb5228f31670b790051c8aa329c2692c8ad92..92bf2f2e7cdd241d1b4019c0ed72ce72fbb95d11 100644 (file)
@@ -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();