On Mon, Dec 01, 2014 at 04:27:44PM -0500, Boris Ostrovsky wrote: > Paravirtual guests are not expected to load microcode into processors > and therefore it is not necessary to initialize microcode loading > logic. CC-ing the KVM folks since they use the paravirt interface too. > > In fact, under certain circumstances initializing this logic may cause > the guest to crash. Specifically, 32-bit kernels use __pa_nodebug() > macro which does not work in Xen (the code path that leads to this macro > happens during resume when we call mc_bp_resume()->load_ucode_ap() > ->check_loader_disabled_ap()) > > Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> > --- > arch/x86/kernel/cpu/microcode/core.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c > index 2ce9051..ebd232d 100644 > --- a/arch/x86/kernel/cpu/microcode/core.c > +++ b/arch/x86/kernel/cpu/microcode/core.c > @@ -557,7 +557,7 @@ static int __init microcode_init(void) > struct cpuinfo_x86 *c = &cpu_data(0); > int error; > > - if (dis_ucode_ldr) > + if (paravirt_enabled() || dis_ucode_ldr) > return 0; > > if (c->x86_vendor == X86_VENDOR_INTEL) > -- > 1.7.1 > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
