x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on hypervisors
authorPaolo Bonzini <pbonzini@redhat.com>
Tue, 10 Oct 2017 10:12:57 +0000 (12:12 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 12 Oct 2017 15:10:10 +0000 (17:10 +0200)
commitcc6afe2240298049585e86b1ade85efc8a7f225d
tree91609c87a75230a6b0357332734e176a60c24a46
parent67bb8e999e0aeac285d22f0e53c856b9df5282c6
x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on hypervisors

Commit 594a30fb1242 ("x86/apic: Silence "FW_BUG TSC_DEADLINE disabled
due to Errata" on CPUs without the feature", 2017-08-30) was also about
silencing the warning on VirtualBox; however, KVM does expose the TSC
deadline timer, and it's virtualized so that it is immune from CPU errata.

Therefore, booting 4.13 with "-cpu Haswell" shows this in the logs:

     [    0.000000] [Firmware Bug]: TSC_DEADLINE disabled due to Errata;
                    please update microcode to version: 0xb2 (or later)

Even if you had a hypervisor that does _not_ virtualize the TSC deadline
and rather exposes the hardware one, it should be the hypervisors task
to update microcode and possibly hide the flag from CPUID.  So just
hide the message when running on _any_ hypervisor, not just those that
do not support the TSC deadline timer.

The older check still makes sense, so keep it.

Fixes: bd9240a18e ("x86/apic: Add TSC_DEADLINE quirk due to errata")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1507630377-54471-1-git-send-email-pbonzini@redhat.com
arch/x86/kernel/apic/apic.c