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| author | Peter Zijlstra <peterz@infradead.org> | 2022-06-14 23:16:04 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-06-27 10:34:00 +0200 |
| commit | d7caac991feeef1b871ee6988fd2c9725df09039 (patch) | |
| tree | 3898bfd6d98b4721394662c2af34ab2c69fbc558 /arch/x86/kernel/cpu/hygon.c | |
| parent | a09a6e2399ba0595c3042b3164f3ca68a3cff33e (diff) | |
| download | linux-d7caac991feeef1b871ee6988fd2c9725df09039.tar.gz | |
x86/cpu/amd: Add Spectral Chicken
Zen2 uarchs have an undocumented, unnamed, MSR that contains a chicken
bit for some speculation behaviour. It needs setting.
Note: very belatedly AMD released naming; it's now officially called
MSR_AMD64_DE_CFG2 and MSR_AMD64_DE_CFG2_SUPPRESS_NOBR_PRED_BIT
but shall remain the SPECTRAL CHICKEN.
Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86/kernel/cpu/hygon.c')
| -rw-r--r-- | arch/x86/kernel/cpu/hygon.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c index 3fcdda4c1e11..21fd425088fe 100644 --- a/arch/x86/kernel/cpu/hygon.c +++ b/arch/x86/kernel/cpu/hygon.c @@ -302,6 +302,12 @@ static void init_hygon(struct cpuinfo_x86 *c) /* get apicid instead of initial apic id from cpuid */ c->apicid = hard_smp_processor_id(); + /* + * XXX someone from Hygon needs to confirm this DTRT + * + init_spectral_chicken(c); + */ + set_cpu_cap(c, X86_FEATURE_ZEN); set_cpu_cap(c, X86_FEATURE_CPB); |