mainline inclusion from mainline-5.6 commit 1e41a766c98b481400ab8c5a7aa8ea63a1bb03de category: x86/speculation/spectre_v2

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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@zhaoxin.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/1579227872-26972-2-git-send-email-TonyWWang-oc@zha... Signed-off-by: LeoLiu-oc LeoLiu-oc@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 a5954a2f8591..246f98153240 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -954,6 +954,7 @@ 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 } @@ -1014,6 +1015,10 @@ 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), {} };

@@ -1068,7 +1073,9 @@ 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) &&