6.6-stable review patch. If anyone has any objections, please let me know.
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From: Sean Christopherson seanjc@google.com
[ Upstream commit 492077668fb453b8b16c842fcf3fafc2ebc190e9 ]
When ensuring EFER.AUTOIBRS is set, WARN only on a negative return code from msr_set_bit(), as '1' is used to indicate the WRMSR was successful ('0' indicates the MSR bit was already set).
Fixes: 8cc68c9c9e92 ("x86/CPU/AMD: Make sure EFER[AIBRSE] is set") Reported-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Sean Christopherson seanjc@google.com Signed-off-by: Ingo Molnar mingo@kernel.org Link: https://lore.kernel.org/r/Z1MkNofJjt7Oq0G6@google.com Closes: https://lore.kernel.org/all/20241205220604.GA2054199@thelio-3990X Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/cpu/amd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 145c81c68394b..9413fb767c6a7 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -1205,7 +1205,7 @@ static void init_amd(struct cpuinfo_x86 *c) */ if (spectre_v2_in_eibrs_mode(spectre_v2_enabled) && cpu_has(c, X86_FEATURE_AUTOIBRS)) - WARN_ON_ONCE(msr_set_bit(MSR_EFER, _EFER_AUTOIBRS)); + WARN_ON_ONCE(msr_set_bit(MSR_EFER, _EFER_AUTOIBRS) < 0);
if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && cpu_has_amd_erratum(c, amd_erratum_1485))