Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752574AbbHaKmO (ORCPT ); Mon, 31 Aug 2015 06:42:14 -0400 Received: from mail-lb0-f180.google.com ([209.85.217.180]:36535 "EHLO mail-lb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751372AbbHaKmM (ORCPT ); Mon, 31 Aug 2015 06:42:12 -0400 Date: Mon, 31 Aug 2015 12:43:33 +0200 From: Christoffer Dall To: Eric Auger Cc: eric.auger@st.com, marc.zyngier@arm.com, drjones@redhat.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, patches@linaro.org, pbonzini@redhat.com Subject: Re: [PATCH v2 4/4] KVM: arm/arm64: implement kvm_arm_[halt,resume]_guest Message-ID: <20150831104333.GO24113@cbox> References: <1438963713-10460-1-git-send-email-eric.auger@linaro.org> <1438963713-10460-5-git-send-email-eric.auger@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1438963713-10460-5-git-send-email-eric.auger@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4457 Lines: 142 On Fri, Aug 07, 2015 at 06:08:33PM +0200, Eric Auger wrote: > We introduce kvm_arm_halt_guest and resume functions. They > will be used for IRQ forward state change. > > Halt is synchronous and prevents the guest from being re-entered. > We use the same mechanism put in place for PSCI former pause, > now renamed power_off. A new flag is introduced in arch vcpu state, > pause, only meant to be used by those functions. > > Signed-off-by: Eric Auger > > --- > v1 -> v2: > - check pause in kvm_arch_vcpu_runnable > - we cannot use kvm_vcpu_block since this latter would exit on > IRQ/FIQ and this is not what we want > --- > arch/arm/include/asm/kvm_host.h | 3 +++ > arch/arm/kvm/arm.c | 35 +++++++++++++++++++++++++++++++---- > arch/arm64/include/asm/kvm_host.h | 3 +++ > 3 files changed, 37 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 304004d..dac85f6 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -132,6 +132,9 @@ struct kvm_vcpu_arch { > /* vcpu power-off state */ > bool power_off; > > + /* Exit and don't run the guest (internal implementation need) */ Why exit? I think it's slightly more correct to just say. "Don't run the guest (internal implementation need)" > + bool pause; > + > /* IO related fields */ > struct kvm_decode mmio_decode; > > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index cc404a8..0529b38 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -348,7 +348,7 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, > int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) > { > return ((!!v->arch.irq_lines || kvm_vgic_vcpu_pending_irq(v)) > - && !v->arch.power_off); > + && !v->arch.power_off && !v->arch.pause); > } > > /* Just ensure a guest exit from a particular CPU */ > @@ -474,11 +474,38 @@ bool kvm_arch_intc_initialized(struct kvm *kvm) > return vgic_initialized(kvm); > } > > +static void kvm_arm_halt_guest(struct kvm *kvm) __maybe_unused; > +static void kvm_arm_resume_guest(struct kvm *kvm) __maybe_unused; > + > +static void kvm_arm_halt_guest(struct kvm *kvm) > +{ > + int i; > + struct kvm_vcpu *vcpu; > + > + kvm_for_each_vcpu(i, vcpu, kvm) > + vcpu->arch.pause = true; > + force_vm_exit(cpu_all_mask); > +} > + > +static void kvm_arm_resume_guest(struct kvm *kvm) > +{ > + int i; > + struct kvm_vcpu *vcpu; > + > + kvm_for_each_vcpu(i, vcpu, kvm) { > + wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu); > + > + vcpu->arch.pause = false; > + wake_up_interruptible(wq); > + } > +} > + > static void vcpu_sleep(struct kvm_vcpu *vcpu) > { > wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu); > > - wait_event_interruptible(*wq, !vcpu->arch.power_off); > + wait_event_interruptible(*wq, ((!vcpu->arch.power_off) && > + (!vcpu->arch.pause))); > } > > static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu) > @@ -528,7 +555,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > > update_vttbr(vcpu->kvm); > > - if (vcpu->arch.power_off) > + if (vcpu->arch.power_off || vcpu->arch.pause) > vcpu_sleep(vcpu); > > /* > @@ -556,7 +583,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > } > > if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) || > - vcpu->arch.power_off) { > + vcpu->arch.power_off || vcpu->arch.pause) { > local_irq_enable(); > kvm_vgic_sync_hwstate(vcpu); > preempt_enable(); > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 009da6b..69e3785 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -125,6 +125,9 @@ struct kvm_vcpu_arch { > /* vcpu power-off state */ > bool power_off; > > + /* Don't run the guest */ Can we have the same comment on the arm and arm64 version? > + bool pause; > + > /* IO related fields */ > struct kvm_decode mmio_decode; > > -- > 1.9.1 > Besides these commenting nits, I think this looks reasonable overall. Reviewed-by: Christoffer Dall On the series. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/