Commit e3fd08af authored by Ashish Kalra's avatar Ashish Kalra Committed by Borislav Petkov (AMD)
Browse files

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: default avatarJeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Signed-off-by: default avatarAshish Kalra <ashish.kalra@amd.com>
Signed-off-by: default avatarMichael Roth <michael.roth@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240126041126.1927228-6-michael.roth@amd.com
parent 216d106c

arch/x86/kernel/cpu/mtrr/generic.c

+3 −0
Original line number Diff line number Diff line
@@ -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]"