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authorPawan Gupta <pawan.kumar.gupta@linux.intel.com>2022-04-04 17:35:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-05 10:18:31 -0700
commite2a1256b17b16f9b9adf1b6fea56819e7b68e463 (patch)
treeb3fd79e653f2f7a31c0eddacb8f797890e7ff35a
parent73924ec4d560257004d5b5116b22a3647661e364 (diff)
downloadlinux-e2a1256b17b16f9b9adf1b6fea56819e7b68e463.tar.bz2
x86/speculation: Restore speculation related MSRs during S3 resume
After resuming from suspend-to-RAM, the MSRs that control CPU's speculative execution behavior are not being restored on the boot CPU. These MSRs are used to mitigate speculative execution vulnerabilities. Not restoring them correctly may leave the CPU vulnerable. Secondary CPU's MSRs are correctly being restored at S3 resume by identify_secondary_cpu(). During S3 resume, restore these MSRs for boot CPU when restoring its processor state. Fixes: 772439717dbf ("x86/bugs/intel: Set proper CPU features and setup RDS") Reported-by: Neelima Krishnan <neelima.krishnan@intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com> Acked-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/power/cpu.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index eaec0cb3fe04..3822666fb73d 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -503,10 +503,24 @@ static int pm_cpu_check(const struct x86_cpu_id *c)
return ret;
}
+static void pm_save_spec_msr(void)
+{
+ u32 spec_msr_id[] = {
+ MSR_IA32_SPEC_CTRL,
+ MSR_IA32_TSX_CTRL,
+ MSR_TSX_FORCE_ABORT,
+ MSR_IA32_MCU_OPT_CTRL,
+ MSR_AMD64_LS_CFG,
+ };
+
+ msr_build_context(spec_msr_id, ARRAY_SIZE(spec_msr_id));
+}
+
static int pm_check_save_msr(void)
{
dmi_check_system(msr_save_dmi_table);
pm_cpu_check(msr_save_cpu_table);
+ pm_save_spec_msr();
return 0;
}