diff options
Diffstat (limited to 'arch/x86/kvm/lapic.c')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 3ebef53d20a0..7e9ac4606279 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -189,15 +189,26 @@ static void recalculate_apic_map(struct kvm *kvm) struct kvm_lapic *apic = vcpu->arch.apic; struct kvm_lapic **cluster; u16 mask; - u32 ldr, aid; + u32 ldr; + u8 xapic_id; + u32 x2apic_id; if (!kvm_apic_present(vcpu)) continue; - aid = apic_x2apic_mode(apic) ? kvm_x2apic_id(apic) - : kvm_xapic_id(apic); - if (aid <= new->max_apic_id) - new->phys_map[aid] = apic; + xapic_id = kvm_xapic_id(apic); + x2apic_id = kvm_x2apic_id(apic); + + /* Hotplug hack: see kvm_apic_match_physical_addr(), ... */ + if ((apic_x2apic_mode(apic) || x2apic_id > 0xff) && + x2apic_id <= new->max_apic_id) + new->phys_map[x2apic_id] = apic; + /* + * ... xAPIC ID of VCPUs with APIC ID > 0xff will wrap-around, + * prevent them from masking VCPUs with APIC ID <= 0xff. + */ + if (!apic_x2apic_mode(apic) && !new->phys_map[xapic_id]) + new->phys_map[xapic_id] = apic; ldr = kvm_lapic_get_reg(apic, APIC_LDR); @@ -604,6 +615,15 @@ static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda) if (apic_x2apic_mode(apic)) return mda == kvm_x2apic_id(apic); + /* + * Hotplug hack: Make LAPIC in xAPIC mode also accept interrupts as if + * it were in x2APIC mode. Hotplugged VCPUs start in xAPIC mode and + * this allows unique addressing of VCPUs with APIC ID over 0xff. + * The 0xff condition is needed because writeable xAPIC ID. + */ + if (kvm_x2apic_id(apic) > 0xff && mda == kvm_x2apic_id(apic)) + return true; + return mda == kvm_xapic_id(apic); } |