[ck] [patch v1 1/2] x86/speculation/spectre_v2: Exclude Zhaoxin CPUs from SPECTRE_V2

commit 1e41a766c98b481400ab8c5a7aa8ea63a1bb03de upstream. New Zhaoxin family 7 CPUs are not affected by SPECTRE_V2. So define a separate cpu_vuln_whitelist bit NO_SPECTRE_V2 and add these CPUs to the cpu vulnerability whitelist. Signed-off-by: Tony W Wang-oc <TonyWWang-oc(a)zhaoxin.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Link: https://lore.kernel.org/r/1579227872-26972-2-git-send-email-TonyWWang-oc@zh… Signed-off-by: LeoLiu-oc <LeoLiu-oc(a)zhaoxin.com> --- arch/x86/kernel/cpu/common.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 1dc4ec01dad1..1560b87ca1ee 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -937,6 +937,7 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c) #define MSBDS_ONLY BIT(5) #define NO_SWAPGS BIT(6) #define NO_ITLB_MULTIHIT BIT(7) +#define NO_SPECTRE_V2 BIT(8) #define VULNWL(_vendor, _family, _model, _whitelist) \ { X86_VENDOR_##_vendor, _family, _model, X86_FEATURE_ANY, _whitelist } @@ -997,6 +998,10 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = { /* FAMILY_ANY must be last, otherwise 0x0f - 0x12 matches won't work */ VULNWL_AMD(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT), VULNWL_HYGON(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT), + + /* Zhaoxin Family 7 */ + VULNWL(CENTAUR, 7, X86_MODEL_ANY, NO_SPECTRE_V2), + VULNWL(ZHAOXIN, 7, X86_MODEL_ANY, NO_SPECTRE_V2), {} }; @@ -1051,7 +1056,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) return; setup_force_cpu_bug(X86_BUG_SPECTRE_V1); - setup_force_cpu_bug(X86_BUG_SPECTRE_V2); + + if (!cpu_matches(cpu_vuln_whitelist, NO_SPECTRE_V2)) + setup_force_cpu_bug(X86_BUG_SPECTRE_V2); if (!cpu_matches(cpu_vuln_whitelist, NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) && -- 2.20.1