[Devel] [PATCH rh7 v1] KVM: x86: set TMR when the interrupt is accepted

[Konstantin Khorenko]

An ack from you?

--
Best regards,

Konstantin Khorenko,
Virtuozzo Linux Kernel Team

On 02/13/2016 01:02 PM, Pavel Butsykin wrote:
> From: Paolo Bonzini <pbonzini at redhat.com>
>
> Do not compute TMR in advance. Instead, set the TMR just before the interrupt
> is accepted into the IRR. This limits the coupling between IOAPIC and LAPIC.
>
> Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
> Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
> ---
>   arch/x86/kvm/ioapic.c |  6 +-----
>   arch/x86/kvm/ioapic.h |  3 +--
>   arch/x86/kvm/lapic.c  | 19 ++++++++++---------
>   arch/x86/kvm/lapic.h  |  1 -
>   arch/x86/kvm/x86.c    |  5 +----
>   5 files changed, 13 insertions(+), 21 deletions(-)
>
> diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
> index d442d94..dc2ae8d 100644
> --- a/arch/x86/kvm/ioapic.c
> +++ b/arch/x86/kvm/ioapic.c
> @@ -246,8 +246,7 @@ static void update_handled_vectors(struct kvm_ioapic *ioapic)
>   	smp_wmb();
>   }
>
> -void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
> -			u32 *tmr)
> +void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
>   {
>   	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
>   	union kvm_ioapic_redirect_entry *e;
> @@ -265,9 +264,6 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
>   			     kvm_apic_pending_eoi(vcpu, e->fields.vector))) {
>   				__set_bit(e->fields.vector,
>   					(unsigned long *)eoi_exit_bitmap);
> -				if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG)
> -					__set_bit(e->fields.vector,
> -						(unsigned long *)tmr);
>   			}
>   		}
>   	}
> diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
> index a5cdfc0..652d5c5 100644
> --- a/arch/x86/kvm/ioapic.h
> +++ b/arch/x86/kvm/ioapic.h
> @@ -114,7 +114,6 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
>   		struct kvm_lapic_irq *irq, unsigned long *dest_map);
>   int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
>   int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
> -void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
> -			u32 *tmr);
> +void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
>
>   #endif
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 07284ef..f42d8e4 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -552,15 +552,6 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu)
>   	__clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
>   }
>
> -void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
> -{
> -	struct kvm_lapic *apic = vcpu->arch.apic;
> -	int i;
> -
> -	for (i = 0; i < 8; i++)
> -		apic_set_reg(apic, APIC_TMR + 0x10 * i, tmr[i]);
> -}
> -
>   static void apic_update_ppr(struct kvm_lapic *apic)
>   {
>   	u32 tpr, isrv, ppr, old_ppr;
> @@ -765,6 +756,9 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
>   	case APIC_DM_LOWEST:
>   		vcpu->arch.apic_arb_prio++;
>   	case APIC_DM_FIXED:
> +		if (unlikely(trig_mode && !level))
> +			break;
> +
>   		/* FIXME add logic for vcpu on reset */
>   		if (unlikely(!apic_enabled(apic)))
>   			break;
> @@ -774,6 +768,13 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
>   		if (dest_map)
>   			__set_bit(vcpu->vcpu_id, dest_map);
>
> +		if (apic_test_vector(vector, apic->regs + APIC_TMR) != !!trig_mode) {
> +			if (trig_mode)
> +				apic_set_vector(vector, apic->regs + APIC_TMR);
> +			else
> +				apic_clear_vector(vector, apic->regs + APIC_TMR);
> +		}
> +
>   		if (kvm_x86_ops->deliver_posted_interrupt)
>   			kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
>   		else {
> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
> index b5e88db..20013c9 100644
> --- a/arch/x86/kvm/lapic.h
> +++ b/arch/x86/kvm/lapic.h
> @@ -57,7 +57,6 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value);
>   u64 kvm_lapic_get_base(struct kvm_vcpu *vcpu);
>   void kvm_apic_set_version(struct kvm_vcpu *vcpu);
>
> -void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr);
>   void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
>   int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 dest);
>   int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda);
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 5a64850..7969de2 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6228,18 +6228,15 @@ static void process_smi(struct kvm_vcpu *vcpu)
>   static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
>   {
>   	u64 eoi_exit_bitmap[4];
> -	u32 tmr[8];
>
>   	if (!kvm_apic_hw_enabled(vcpu->arch.apic))
>   		return;
>
>   	memset(eoi_exit_bitmap, 0, 32);
> -	memset(tmr, 0, 32);
>
>   	kvm_x86_ops->sync_pir_to_irr(vcpu);
> -	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
> +	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap);
>   	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
> -	kvm_apic_update_tmr(vcpu, tmr);
>   }
>
>   void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
>