From 594a30fb12424717a41c62323d2a8bf167dbccad Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 30 Aug 2017 12:58:11 +0200 Subject: [PATCH] x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on CPUs without the feature When booting 4.13 on a VirtualBox VM on a Skylake host the following error shows up in the logs: [ 0.000000] [Firmware Bug]: TSC_DEADLINE disabled due to Errata; please update microcode to version: 0xb2 (or later) This is caused by apic_check_deadline_errata() only checking CPU model and not the X86_FEATURE_TSC_DEADLINE_TIMER flag (which VirtualBox does NOT export to the guest), combined with VirtualBox not exporting the micro-code version to the guest. This commit adds a check for X86_FEATURE_TSC_DEADLINE_TIMER to apic_check_deadline_errata(), silencing this error on VirtualBox VMs. Signed-off-by: Hans de Goede Acked-by: Thomas Gleixner Cc: Frank Mehnert Cc: Linus Torvalds Cc: Michael Thayer Cc: Michal Necasek Cc: Peter Zijlstra Fixes: bd9240a18e ("x86/apic: Add TSC_DEADLINE quirk due to errata") Link: http://lkml.kernel.org/r/20170830105811.27539-1-hdegoede@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/apic.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index eebee4cbc14b..7834f73efbf1 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -597,9 +597,13 @@ static const struct x86_cpu_id deadline_match[] = { static void apic_check_deadline_errata(void) { - const struct x86_cpu_id *m = x86_match_cpu(deadline_match); + const struct x86_cpu_id *m; u32 rev; + if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) + return; + + m = x86_match_cpu(deadline_match); if (!m) return; -- 2.20.1