pr_info("Hyper-V: Using enlightened APIC (%s mode)",
x2apic_enabled() ? "x2apic" : "xapic");
/*
- * With x2apic, architectural x2apic MSRs are equivalent to the
- * respective synthetic MSRs, so there's no need to override
- * the apic accessors. The only exception is
- * hv_apic_eoi_write, because it benefits from lazy EOI when
- * available, but it works for both xapic and x2apic modes.
+ * When in x2apic mode, don't use the Hyper-V specific APIC
+ * accessors since the field layout in the ICR register is
+ * different in x2apic mode. Furthermore, the architectural
+ * x2apic MSRs function just as well as the Hyper-V
+ * synthetic APIC MSRs, so there's no benefit in having
+ * separate Hyper-V accessors for x2apic mode. The only
+ * exception is hv_apic_eoi_write, because it benefits from
+ * lazy EOI when available, but the same accessor works for
+ * both xapic and x2apic because the field layout is the same.
*/
apic_set_eoi_write(hv_apic_eoi_write);
if (!x2apic_enabled()) {