From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Mueller Subject: Re: [PATCH v5 12/15] KVM: s390: do not restore IAM immediately before SIE entry Date: Mon, 7 Jan 2019 18:53:23 +0100 Message-ID: <0c05a099-199e-426f-93af-b8614a3f800e@linux.ibm.com> References: <20181219191756.57973-1-mimu@linux.ibm.com> <20181219191756.57973-13-mimu@linux.ibm.com> <5b427ccb-b0b4-f411-a9fc-6b8f8a60b734@linux.ibm.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: <5b427ccb-b0b4-f411-a9fc-6b8f8a60b734@linux.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: pmorel@linux.ibm.com, KVM Mailing List Cc: Linux-S390 Mailing List , linux-kernel@vger.kernel.org, kvm390-list@tuxmaker.boeblingen.de.ibm.com, Martin Schwidefsky , Heiko Carstens , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Halil Pasic List-ID: On 03.01.19 16:00, Pierre Morel wrote: > On 19/12/2018 20:17, Michael Mueller wrote: >> The IAM shall no be restored when deliverable interruptions are >> delivered to vcpus by means of the PSW swap mechanism. That would >> trigger the GIB alert millicode although we know that SIE will be >> able to handle the pending interruption on entry. >> >> Signed-off-by: Michael Mueller >> --- >>   arch/s390/kvm/interrupt.c | 8 ++++---- >>   1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c >> index 8307717e3caf..48a93f5e5333 100644 >> --- a/arch/s390/kvm/interrupt.c >> +++ b/arch/s390/kvm/interrupt.c >> @@ -328,11 +328,11 @@ static unsigned long disable_iscs(struct >> kvm_vcpu *vcpu, >>       return active_mask; >>   } >> -static unsigned long deliverable_irqs(struct kvm_vcpu *vcpu) >> +static unsigned long deliverable_irqs(struct kvm_vcpu *vcpu, u16 >> irq_flags) >>   { >>       unsigned long active_mask; >> -    active_mask = pending_irqs(vcpu, IRQ_MASK_ALL); >> +    active_mask = pending_irqs(vcpu, irq_flags); >>       if (!active_mask) >>           return 0; >> @@ -1090,7 +1090,7 @@ int kvm_s390_ext_call_pending(struct kvm_vcpu >> *vcpu) >>   int kvm_s390_vcpu_has_irq(struct kvm_vcpu *vcpu, int exclude_stop) >>   { >> -    if (deliverable_irqs(vcpu)) >> +    if (deliverable_irqs(vcpu, IRQ_MASK_ALL | IRQ_FLAG_IAM)) > > Why do we need to restore IAM here? please see kvm_s390_handle_wait() It calls kvm_arch_vcpu_runnable() / kvm_s390_vcpu_has_irq() That's the place where we want the IAM to be restored when no ISC is pending in the IPM anymore. > > >