From: Tony W Wang-oc <[email protected]>

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 <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: 
https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 arch/x86/kernel/cpu/common.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1024,6 +1024,7 @@ static void identify_cpu_without_cpuid(s
 #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 }
@@ -1085,6 +1086,10 @@ static const __initconst struct x86_cpu_
        /* 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),
        {}
 };
 
@@ -1117,7 +1122,9 @@ static void __init cpu_set_bug_bits(stru
                return;
 
        setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
-       setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
+       if (!cpu_matches(NO_SPECTRE_V2))
+               setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
 
        if (!cpu_matches(NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) &&
           !cpu_has(c, X86_FEATURE_AMD_SSB_NO))


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