From e3fd08afb7c350d5612f113eadfb4ebb6ed08deb Mon Sep 17 00:00:00 2001 From: Ashish Kalra Date: Thu, 25 Jan 2024 22:11:05 -0600 Subject: [PATCH] x86/mtrr: Don't print errors if MtrrFixDramModEn is set when SNP enabled SNP enabled platforms require the MtrrFixDramModeEn bit to be set across all CPUs when SNP is enabled. Therefore, don't print error messages when MtrrFixDramModeEn is set when bringing CPUs online. Closes: https://lore.kernel.org/kvm/68b2d6bf-bce7-47f9-bebb-2652cc923ff9@linux.microsoft.com/ Reported-by: Jeremi Piotrowski Signed-off-by: Ashish Kalra Signed-off-by: Michael Roth Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240126041126.1927228-6-michael.roth@amd.com --- arch/x86/kernel/cpu/mtrr/generic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index d3524778a5451..422a4ddc2ab7c 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -108,6 +108,9 @@ static inline void k8_check_syscfg_dram_mod_en(void) (boot_cpu_data.x86 >= 0x0f))) return; + if (cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return; + rdmsr(MSR_AMD64_SYSCFG, lo, hi); if (lo & K8_MTRRFIXRANGE_DRAM_MODIFY) { pr_err(FW_WARN "MTRR: CPU %u: SYSCFG[MtrrFixDramModEn]" -- 2.30.2