Re: [PATCH v2 2/4] KVM: x86: replace kvm_apic_id with kvm_{x,x2}apic_id

[David Hildenbrand]

        kvm_for_each_vcpu(i, vcpu, kvm)
                if (kvm_apic_present(vcpu))
-                       max_id = max(max_id, kvm_apic_id(vcpu->arch.apic));
+                       max_id = max(max_id, kvm_x2apic_id(vcpu->arch.apic));
        new = kvm_kvzalloc(sizeof(struct kvm_apic_map) +
                           sizeof(struct kvm_lapic *) * ((u64)max_id + 1));
@@ -179,16 +189,23 @@ 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 = kvm_apic_id(apic);

think I'd even prefer here a simple

aid = kvm_xapic_id(apic);
if (apic_x2apic_mode(apic))
        aid = kvm_x2apic_id(apic);

that would keep changes minimal and I don't really see any benefit in 
the code when splitting handling up.

Patch 4 then simply can fixup setting code

if (aid <= new->max_apic_id && !new->phys_map[aid])
        new->phys_map[aid] = apic;

(if I am not missing some important corner case here)


-               ldr = kvm_lapic_get_reg(apic, APIC_LDR);
+               xapic_id = kvm_xapic_id(apic);
+               x2apic_id = kvm_x2apic_id(apic);

-               if (aid <= new->max_apic_id)
-                       new->phys_map[aid] = apic;
+               if (apic_x2apic_mode(apic) &&
+                               x2apic_id <= new->max_apic_id)
+                       new->phys_map[x2apic_id] = apic;
+               else if (!apic_x2apic_mode(apic))


This looks good to me.

--

David