[PATCH v1 2/3] x86/cpu/AMD: Use LFENCE_RDTSC instead of MFENCE_RDTSC

[Tom Lendacky]

With LFENCE now a serializing instruction, set the LFENCE_RDTSC
feature since the LFENCE instruction has less overhead than the
MFENCE instruction.

Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
 arch/x86/kernel/cpu/amd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index fbd439e..b221fe5 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -838,8 +838,8 @@ static void init_amd(struct cpuinfo_x86 *c)
                msr_set_bit(MSR_F10H_DECFG,
                            MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT);
 
-               /* MFENCE stops RDTSC speculation */
-               set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
+               /* A serializing LFENCE stops RDTSC speculation */
+               set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
        }
 
        /*