From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Mueller Subject: Re: [PATCH v5 05/15] KVM: s390: unify pending_irqs() and pending_irqs_no_gisa() Date: Thu, 20 Dec 2018 13:33:14 +0100 Message-ID: <83553348-0b10-8bcc-34b0-c87a0e2f95ac@linux.ibm.com> References: <20181219191756.57973-1-mimu@linux.ibm.com> <20181219191756.57973-6-mimu@linux.ibm.com> <20181220120614.65acacac.cohuck@redhat.com> <62bf4bcf-585f-ddfc-e7a5-18fc946819d9@linux.ibm.com> <20181220132130.33a417fa.cohuck@redhat.com> Reply-To: mimu@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181220132130.33a417fa.cohuck@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Cornelia Huck Cc: KVM Mailing List , Linux-S390 Mailing List , linux-kernel@vger.kernel.org, Martin Schwidefsky , Heiko Carstens , Christian Borntraeger , Janosch Frank , David Hildenbrand , Halil Pasic , Pierre Morel List-ID: On 20.12.18 13:21, Cornelia Huck wrote: > On Thu, 20 Dec 2018 12:49:56 +0100 > Michael Mueller wrote: > >> On 20.12.18 12:06, Cornelia Huck wrote: >>> On Wed, 19 Dec 2018 20:17:46 +0100 >>> Michael Mueller wrote: >>> >>>> Use a single function with parameter irq_flags to differentiate >>>> between cases. >>>> >>>> New irq flag: >>>> IRQ_FLAG_LOCAL: include vcpu local interruptions pending >>>> IRQ_FLAG_FLOATING: include vcpu floating interruptions pending >>>> IRQ_FLAG_GISA: include GISA interruptions pending in IPM >>> >>> I presume that means that irqs may be in more than one set? Or are gisa >>> irqs not considered floating irqs, because they use a different >>> mechanism? >> >> Currently, the interruptions managed in GISA are floating only. But >> that might change in future. The idea is not to subsume IRQ_FLAG_GISA >> in IRQ_FLAG_FLOATING but to be able to address the right set of >> procedures to determine the irq pending set for a given subset of irq >> types that have different implementations. >> >> There might be a better name for IRQ_FLAG_FLOATING then? > > So the split is: > > - local interrupts that are pending via kvm structures; > - floating interrupts that are pending via kvm structures; > - interrupts that are pending via gisa? > > If so, what about > - IRQ_FLAG_KVM_LOCAL > - IRQ_FLAG_KVM_FLOATING > - IRQ_FLAG_GISA (or maybe IRQ_FLAG_GISA_FLOATING, if you need to > distinguish those later on?) yes, that's the split and I will go with: IRQ_FLAG_KVM_LOCAL IRQ_FLAG_KVM_FLOATING IRQ_FLAG_GISA initially. The floating and local selection can be done by related masks IRQ_MASK_LOCAL IRQ_MASK_FLOATING if required. Thanks! > >> >>> >>>> >>>> New irq masks: >>>> IRQ_MASK_ALL: include all types >>>> IRQ_MASK_NO_GISA: include all types but GISA >>>> >>>> Examples: >>>> pending_irqs(vcpu, IRQ_MASK_ALL) >>>> pending_irqs(vcpu, IRQ_MASK_NO_GISA) >>>> >>>> There will be more irq flags with upcoming patches. >>>> >>>> Signed-off-by: Michael Mueller >>>> --- >>>> arch/s390/kvm/interrupt.c | 33 +++++++++++++++++++++------------ >>>> 1 file changed, 21 insertions(+), 12 deletions(-) >>>> >>>> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c >>>> index 093b568b6356..4ab20d2eb180 100644 >>>> --- a/arch/s390/kvm/interrupt.c >>>> +++ b/arch/s390/kvm/interrupt.c >>>> @@ -31,6 +31,13 @@ >>>> #define PFAULT_DONE 0x0680 >>>> #define VIRTIO_PARAM 0x0d00 >>>> >>>> +#define IRQ_FLAG_LOCAL 0x8000 /* include local interruption pending mask */ >>>> +#define IRQ_FLAG_FLOATING 0x4000 /* include float interruption pending mask */ >>>> +#define IRQ_FLAG_GISA 0x2000 /* include GISA interruption pending mask */ >>>> + >>>> +#define IRQ_MASK_ALL (IRQ_FLAG_LOCAL | IRQ_FLAG_FLOATING | IRQ_FLAG_GISA) >>>> +#define IRQ_MASK_NO_GISA (IRQ_MASK_ALL & ~IRQ_FLAG_GISA) >>>> + >>>> /* handle external calls via sigp interpretation facility */ >>>> static int sca_ext_call_pending(struct kvm_vcpu *vcpu, int *src_id) >>>> { >>>> @@ -237,16 +244,18 @@ static inline int kvm_s390_gisa_tac_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gis >>>> return test_and_clear_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa); >>>> } >>>> >>>> -static inline unsigned long pending_irqs_no_gisa(struct kvm_vcpu *vcpu) >>>> +static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu, u16 irq_flags) >>> >>> Any deeper reason why this is a u16? 16 bits should be enough for >>> everyone? :) >> >> I want to use the 8 bits for the IRQ type and the other 8 for additional >> controls, see: "KVM: s390: restore IAM in get_ipm() when IPM is clean" > > Still need to look at that patch, but my question mainly was "why only > 16 bits"? I would think making this local variable larger is cheap. > I will enlarge the flag mask to u32 with 16 bits for the IRQ types then. >> >>> >>>> { >>>> - return vcpu->kvm->arch.float_int.pending_irqs | >>>> - vcpu->arch.local_int.pending_irqs; >>>> -} > -- Mit freundlichen Grüßen / Kind regards Michael Müller IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Matthias Hartmann Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294