From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [RFC v2 2/4] KVM: arm: vgic: fix state machine for forwarded IRQ Date: Wed, 6 May 2015 16:26:49 +0200 Message-ID: <20150506142649.GB6796@cbox> References: <1423642857-24240-1-git-send-email-eric.auger@linaro.org> <1423642857-24240-3-git-send-email-eric.auger@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: eric.auger@st.com, marc.zyngier@arm.com, andre.przywara@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, alex.williamson@redhat.com, patches@linaro.org, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, b.reynal@virtualopensystems.com To: Eric Auger Return-path: Received: from mail-la0-f42.google.com ([209.85.215.42]:35490 "EHLO mail-la0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751116AbbEFO0v (ORCPT ); Wed, 6 May 2015 10:26:51 -0400 Received: by labbd9 with SMTP id bd9so8716787lab.2 for ; Wed, 06 May 2015 07:26:49 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1423642857-24240-3-git-send-email-eric.auger@linaro.org> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Feb 11, 2015 at 09:20:55AM +0100, Eric Auger wrote: > Fix multiple injection of level sensitive forwarded IRQs. > With current code, the second injection fails since the state bitmaps > are not reset (process_maintenance is not called anymore). > > New implementation follows those principles: > - A forwarded IRQ only can be sampled when it is pending why? > - when queueing the IRQ (programming the LR), the pending state is removed > as for edge sensitive IRQs > - an injection of a forwarded IRQ is considered always valid since > coming from the HW and level always is 1. > > Signed-off-by: Eric Auger > > --- > > v1 -> v2: > - integration in new vgic_can_sample_irq > - remove the pending state when programming the LR > --- > virt/kvm/arm/vgic.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c > index cd00cf2..433ecba 100644 > --- a/virt/kvm/arm/vgic.c > +++ b/virt/kvm/arm/vgic.c > @@ -361,7 +361,10 @@ static void vgic_cpu_irq_clear(struct kvm_vcpu *vcpu, int irq) > > static bool vgic_can_sample_irq(struct kvm_vcpu *vcpu, int irq) > { > - return vgic_irq_is_edge(vcpu, irq) || !vgic_irq_is_queued(vcpu, irq); > + bool is_forwarded = (vgic_get_phys_irq(vcpu, irq) >= 0); can you create a wrapper function for is_forwarded? > + > + return vgic_irq_is_edge(vcpu, irq) || !vgic_irq_is_queued(vcpu, irq) || > + (is_forwarded && vgic_dist_irq_is_pending(vcpu, irq)); > } > > static u32 mmio_data_read(struct kvm_exit_mmio *mmio, u32 mask) > @@ -1296,6 +1299,7 @@ static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq) > struct vgic_dist *dist = &vcpu->kvm->arch.vgic; > struct vgic_lr vlr; > int lr; > + bool is_forwarded = (vgic_get_phys_irq(vcpu, irq) >= 0); > > /* Sanitize the input... */ > BUG_ON(sgi_source_id & ~7); > @@ -1331,7 +1335,7 @@ static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq) > vlr.irq = irq; > vlr.source = sgi_source_id; > vlr.state = LR_STATE_PENDING; > - if (!vgic_irq_is_edge(vcpu, irq)) > + if (!vgic_irq_is_edge(vcpu, irq) && !is_forwarded) > vlr.state |= LR_EOI_INT; > > vgic_set_lr(vcpu, lr, vlr); > @@ -1372,11 +1376,12 @@ static bool vgic_queue_sgi(struct kvm_vcpu *vcpu, int irq) > > static bool vgic_queue_hwirq(struct kvm_vcpu *vcpu, int irq) > { > + bool is_forwarded = (vgic_get_phys_irq(vcpu, irq) >= 0); > if (!vgic_can_sample_irq(vcpu, irq)) > return true; /* level interrupt, already queued */ > > if (vgic_queue_irq(vcpu, 0, irq)) { > - if (vgic_irq_is_edge(vcpu, irq)) { > + if (vgic_irq_is_edge(vcpu, irq) || is_forwarded) { > vgic_dist_irq_clear_pending(vcpu, irq); > vgic_cpu_irq_clear(vcpu, irq); > } else { > @@ -1626,14 +1631,17 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid, > int edge_triggered, level_triggered; > int enabled; > bool ret = true; > + bool is_forwarded; > > spin_lock(&dist->lock); > > vcpu = kvm_get_vcpu(kvm, cpuid); > + is_forwarded = (vgic_get_phys_irq(vcpu, irq_num) >= 0); > + > edge_triggered = vgic_irq_is_edge(vcpu, irq_num); > level_triggered = !edge_triggered; > > - if (!vgic_validate_injection(vcpu, irq_num, level)) { > + if (!vgic_validate_injection(vcpu, irq_num, level) && !is_forwarded) { why is it again that we don't trust validate for forwarded irqs? Should it not be checked inside validate? Otherwise, this seems to deserve a comment. > ret = false; > goto out; > } Thanks, -Christoffer From mboxrd@z Thu Jan 1 00:00:00 1970 From: christoffer.dall@linaro.org (Christoffer Dall) Date: Wed, 6 May 2015 16:26:49 +0200 Subject: [RFC v2 2/4] KVM: arm: vgic: fix state machine for forwarded IRQ In-Reply-To: <1423642857-24240-3-git-send-email-eric.auger@linaro.org> References: <1423642857-24240-1-git-send-email-eric.auger@linaro.org> <1423642857-24240-3-git-send-email-eric.auger@linaro.org> Message-ID: <20150506142649.GB6796@cbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Feb 11, 2015 at 09:20:55AM +0100, Eric Auger wrote: > Fix multiple injection of level sensitive forwarded IRQs. > With current code, the second injection fails since the state bitmaps > are not reset (process_maintenance is not called anymore). > > New implementation follows those principles: > - A forwarded IRQ only can be sampled when it is pending why? > - when queueing the IRQ (programming the LR), the pending state is removed > as for edge sensitive IRQs > - an injection of a forwarded IRQ is considered always valid since > coming from the HW and level always is 1. > > Signed-off-by: Eric Auger > > --- > > v1 -> v2: > - integration in new vgic_can_sample_irq > - remove the pending state when programming the LR > --- > virt/kvm/arm/vgic.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c > index cd00cf2..433ecba 100644 > --- a/virt/kvm/arm/vgic.c > +++ b/virt/kvm/arm/vgic.c > @@ -361,7 +361,10 @@ static void vgic_cpu_irq_clear(struct kvm_vcpu *vcpu, int irq) > > static bool vgic_can_sample_irq(struct kvm_vcpu *vcpu, int irq) > { > - return vgic_irq_is_edge(vcpu, irq) || !vgic_irq_is_queued(vcpu, irq); > + bool is_forwarded = (vgic_get_phys_irq(vcpu, irq) >= 0); can you create a wrapper function for is_forwarded? > + > + return vgic_irq_is_edge(vcpu, irq) || !vgic_irq_is_queued(vcpu, irq) || > + (is_forwarded && vgic_dist_irq_is_pending(vcpu, irq)); > } > > static u32 mmio_data_read(struct kvm_exit_mmio *mmio, u32 mask) > @@ -1296,6 +1299,7 @@ static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq) > struct vgic_dist *dist = &vcpu->kvm->arch.vgic; > struct vgic_lr vlr; > int lr; > + bool is_forwarded = (vgic_get_phys_irq(vcpu, irq) >= 0); > > /* Sanitize the input... */ > BUG_ON(sgi_source_id & ~7); > @@ -1331,7 +1335,7 @@ static bool vgic_queue_irq(struct kvm_vcpu *vcpu, u8 sgi_source_id, int irq) > vlr.irq = irq; > vlr.source = sgi_source_id; > vlr.state = LR_STATE_PENDING; > - if (!vgic_irq_is_edge(vcpu, irq)) > + if (!vgic_irq_is_edge(vcpu, irq) && !is_forwarded) > vlr.state |= LR_EOI_INT; > > vgic_set_lr(vcpu, lr, vlr); > @@ -1372,11 +1376,12 @@ static bool vgic_queue_sgi(struct kvm_vcpu *vcpu, int irq) > > static bool vgic_queue_hwirq(struct kvm_vcpu *vcpu, int irq) > { > + bool is_forwarded = (vgic_get_phys_irq(vcpu, irq) >= 0); > if (!vgic_can_sample_irq(vcpu, irq)) > return true; /* level interrupt, already queued */ > > if (vgic_queue_irq(vcpu, 0, irq)) { > - if (vgic_irq_is_edge(vcpu, irq)) { > + if (vgic_irq_is_edge(vcpu, irq) || is_forwarded) { > vgic_dist_irq_clear_pending(vcpu, irq); > vgic_cpu_irq_clear(vcpu, irq); > } else { > @@ -1626,14 +1631,17 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid, > int edge_triggered, level_triggered; > int enabled; > bool ret = true; > + bool is_forwarded; > > spin_lock(&dist->lock); > > vcpu = kvm_get_vcpu(kvm, cpuid); > + is_forwarded = (vgic_get_phys_irq(vcpu, irq_num) >= 0); > + > edge_triggered = vgic_irq_is_edge(vcpu, irq_num); > level_triggered = !edge_triggered; > > - if (!vgic_validate_injection(vcpu, irq_num, level)) { > + if (!vgic_validate_injection(vcpu, irq_num, level) && !is_forwarded) { why is it again that we don't trust validate for forwarded irqs? Should it not be checked inside validate? Otherwise, this seems to deserve a comment. > ret = false; > goto out; > } Thanks, -Christoffer