On 22/05/2015 18:45, Radim Krčmář wrote: > SDM April 2015, 10.12.5 State Changes From xAPIC Mode to x2APIC Mode > • Any APIC ID value written to the memory-mapped local APIC ID register > is not preserved. > > Fix it by sourcing vcpu_id (= initial APIC ID) instead of memory-mapped > APIC ID. Proper use of apic functions would result in two calls to > recalculate_apic_map(), so this patch makes a new helper. > > Signed-off-by: Radim Krčmář <[email protected]> > --- > arch/x86/kvm/lapic.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index dc5b57bb1f76..c2a7d8a7a414 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -240,6 +240,15 @@ static inline void kvm_apic_set_ldr(struct kvm_lapic > *apic, u32 id) > recalculate_apic_map(apic->vcpu->kvm); > } > > +static inline void kvm_apic_set_x2apic_id(struct kvm_lapic *apic, u8 id) > +{ > + u32 ldr = ((id >> 4) << 16) | (1 << (id & 0xf)); > + > + apic_set_reg(apic, APIC_ID, id << 24); > + apic_set_reg(apic, APIC_LDR, ldr); > + recalculate_apic_map(apic->vcpu->kvm); > +} > + > static inline int apic_lvt_enabled(struct kvm_lapic *apic, int lvt_type) > { > return !(kvm_apic_get_reg(apic, lvt_type) & APIC_LVT_MASKED); > @@ -1538,9 +1547,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 > value) > > if ((old_value ^ value) & X2APIC_ENABLE) { > if (value & X2APIC_ENABLE) { > - u32 id = kvm_apic_id(apic); > - u32 ldr = ((id >> 4) << 16) | (1 << (id & 0xf)); > - kvm_apic_set_ldr(apic, ldr); > + kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id); > kvm_x86_ops->set_virtual_x2apic_mode(vcpu, true); > } else > kvm_x86_ops->set_virtual_x2apic_mode(vcpu, false); >
Applied, thanks. Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
