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

Radim Krčmář
2016-12-13T16:31:09Z

There were three calls sites:
- recalculate_apic_map and kvm_apic_match_physical_addr, where it would
only complicate implementation of x2APIC hotplug;
- in apic_debug, where it was still somewhat preserved, but keeping the
old function just for apic_debug was not worth it

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
arch/x86/kvm/lapic.c | 41 ++++++++++++++++++++++++++++++-----------
arch/x86/kvm/lapic.h | 11 -----------
2 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 09edd32b8e42..e645b4bc6437 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -115,6 +115,16 @@ static inline int apic_enabled(struct kvm_lapic *apic)
(LVT_MASK | APIC_MODE_MASK | APIC_INPUT_POLARITY | \
APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER)

+static inline u8 kvm_xapic_id(struct kvm_lapic *apic)
+{
+ return kvm_lapic_get_reg(apic, APIC_ID) >> 24;
+}
+
+static inline u32 kvm_x2apic_id(struct kvm_lapic *apic)
+{
+ return apic->vcpu->vcpu_id;
+}
+
static inline bool kvm_apic_map_get_logical_dest(struct kvm_apic_map *map,
u32 dest_id, struct kvm_lapic ***cluster, u16 *mask) {
switch (map->mode) {
@@ -159,13 +169,13 @@ static void recalculate_apic_map(struct kvm *kvm)
struct kvm_apic_map *new, *old = NULL;
struct kvm_vcpu *vcpu;
int i;
- u32 max_id = 255;
+ u32 max_id = 256; /* enough space for any xAPIC ID */

mutex_lock(&kvm->arch.apic_map_lock);

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);
- 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))
+ new->phys_map[xapic_id] = apic;
+
+ ldr = kvm_lapic_get_reg(apic, APIC_LDR);

if (apic_x2apic_mode(apic)) {
new->mode |= KVM_APIC_MODE_X2APIC;
@@ -250,6 +267,8 @@ static inline void kvm_apic_set_x2apic_id(struct kvm_lapic *apic, u32 id)
{
u32 ldr = ((id >> 4) << 16) | (1 << (id & 0xf));

+ WARN_ON_ONCE(id != apic->vcpu->vcpu_id);
+
kvm_lapic_set_reg(apic, APIC_ID, id);
kvm_lapic_set_reg(apic, APIC_LDR, ldr);
recalculate_apic_map(apic->vcpu->kvm);
@@ -591,9 +610,9 @@ static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda)
return true;

if (apic_x2apic_mode(apic))
- return mda == kvm_apic_id(apic);
+ return mda == kvm_x2apic_id(apic);

- return mda == SET_APIC_DEST_FIELD(kvm_apic_id(apic));
+ return mda == SET_APIC_DEST_FIELD(kvm_xapic_id(apic));
}

static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda)
@@ -1907,9 +1926,9 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
vcpu->arch.apic_arb_prio = 0;
vcpu->arch.apic_attention = 0;

- apic_debug("%s: vcpu=%p, id=%d, base_msr="
+ apic_debug("%s: vcpu=%p, id=0x%x, base_msr="
"0x%016" PRIx64 ", base_address=0x%0lx.\n", __func__,
- vcpu, kvm_apic_id(apic),
+ vcpu, kvm_lapic_get_reg(apic, APIC_ID),
vcpu->arch.apic_base, apic->base_address);
}

diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index e0c80233b3e1..cb16e6fd2330 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -202,17 +202,6 @@ static inline int kvm_lapic_latched_init(struct kvm_vcpu *vcpu)
return lapic_in_kernel(vcpu) && test_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
}

-static inline u32 kvm_apic_id(struct kvm_lapic *apic)
-{
- /* To avoid a race between apic_base and following APIC_ID update when
- * switching to x2apic_mode, the x2apic mode returns initial x2apic id.
- */
- if (apic_x2apic_mode(apic))
- return apic->vcpu->vcpu_id;
-
- return kvm_lapic_get_reg(apic, APIC_ID) >> 24;
-}
-
bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector);

void wait_lapic_expire(struct kvm_vcpu *vcpu);
--
2.11.0