Re: [PATCH] KVM: Call kvm_apic_match_dest() to check destination vcpu

[Gleb Natapov <gleb@redhat.com>]

On Mon, Apr 01, 2013 at 12:42:33AM +0000, Zhang, Yang Z wrote:
> Zhang, Yang Z wrote on 2013-03-21:
> > From: Yang Zhang <yang.z.zhang@Intel.com>
> > 
> > For a given vcpu, kvm_apic_match_dest() will tell you whether
> > the vcpu in the destination list quickly. Drop kvm_calculate_eoi_exitmap()
> > and use kvm_apic_match_dest() instead.
> > 
> > Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
> > ---
> >  arch/x86/kvm/lapic.c |   47 -----------------------------------------------
> >  arch/x86/kvm/lapic.h |    4 ----
> >  virt/kvm/ioapic.c    |    9 ++++-----
> >  3 files changed, 4 insertions(+), 56 deletions(-)
> > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> > index a8e9369..e227474 100644
> > --- a/arch/x86/kvm/lapic.c
> > +++ b/arch/x86/kvm/lapic.c
> > @@ -145,53 +145,6 @@ static inline int kvm_apic_id(struct kvm_lapic *apic)
> >  	return (kvm_apic_get_reg(apic, APIC_ID) >> 24) & 0xff;
> >  }
> > -void kvm_calculate_eoi_exitmap(struct kvm_vcpu *vcpu,
> > -				struct kvm_lapic_irq *irq,
> > -				u64 *eoi_exit_bitmap)
> > -{
> > -	struct kvm_lapic **dst;
> > -	struct kvm_apic_map *map;
> > -	unsigned long bitmap = 1;
> > -	int i;
> > -
> > -	rcu_read_lock();
> > -	map = rcu_dereference(vcpu->kvm->arch.apic_map);
> > -
> > -	if (unlikely(!map)) {
> > -		__set_bit(irq->vector, (unsigned long *)eoi_exit_bitmap);
> > -		goto out;
> > -	}
> > -
> > -	if (irq->dest_mode == 0) { /* physical mode */
> > -		if (irq->delivery_mode == APIC_DM_LOWEST ||
> > -				irq->dest_id == 0xff) {
> > -			__set_bit(irq->vector,
> > -				  (unsigned long *)eoi_exit_bitmap);
> > -			goto out;
> > -		}
> > -		dst = &map->phys_map[irq->dest_id & 0xff];
> > -	} else {
> > -		u32 mda = irq->dest_id << (32 - map->ldr_bits);
> > -
> > -		dst = map->logical_map[apic_cluster_id(map, mda)];
> > -
> > -		bitmap = apic_logical_id(map, mda);
> > -	}
> > -
> > -	for_each_set_bit(i, &bitmap, 16) {
> > -		if (!dst[i])
> > -			continue;
> > -		if (dst[i]->vcpu == vcpu) {
> > -			__set_bit(irq->vector,
> > -				  (unsigned long *)eoi_exit_bitmap);
> > -			break;
> > -		}
> > -	}
> > -
> > -out:
> > -	rcu_read_unlock();
> > -}
> > -
> >  static void recalculate_apic_map(struct kvm *kvm)
> >  {
> >  	struct kvm_apic_map *new, *old = NULL;
> > diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
> > index 2c721b9..baa20cf 100644
> > --- a/arch/x86/kvm/lapic.h
> > +++ b/arch/x86/kvm/lapic.h
> > @@ -160,10 +160,6 @@ static inline u16 apic_logical_id(struct kvm_apic_map
> > *map, u32 ldr)
> >  	return ldr & map->lid_mask;
> >  }
> > -void kvm_calculate_eoi_exitmap(struct kvm_vcpu *vcpu,
> > -				struct kvm_lapic_irq *irq,
> > -				u64 *eoi_bitmap);
> > -
> >  static inline bool kvm_apic_has_events(struct kvm_vcpu *vcpu)
> >  {
> >  	return vcpu->arch.apic->pending_events;
> > diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
> > index ce82b94..b54ddfa 100644
> > --- a/virt/kvm/ioapic.c
> > +++ b/virt/kvm/ioapic.c
> > @@ -132,11 +132,10 @@ void kvm_ioapic_calculate_eoi_exitmap(struct
> > kvm_vcpu *vcpu,
> >  			(e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
> >  			 kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC,
> >  				 index))) {
> > -			irqe.dest_id = e->fields.dest_id; -			irqe.vector =
> > e->fields.vector; -			irqe.dest_mode = e->fields.dest_mode;
> > -			irqe.delivery_mode = e->fields.delivery_mode << 8;
> > -			kvm_calculate_eoi_exitmap(vcpu, &irqe, eoi_exit_bitmap); +			if
> > (kvm_apic_match_dest(vcpu, NULL, 0, +				e->fields.dest_id,
> > e->fields.dest_mode)) +				__set_bit(irqe.vector, +					(unsigned long
> > *)eoi_exit_bitmap);
> >  		}
> >  	}
> >  	spin_unlock(&ioapic->lock);
> > --
> > 1.7.1
> 
> Any comments?
> 
You can drop irqe now since it was needed for
kvm_calculate_eoi_exitmap() call.

--
			Gleb.