From: Marc Zyngier <maz@kernel.org> To: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, Eric Auger <eric.auger@redhat.com>, James Morse <james.morse@arm.com>, Julien Thierry <julien.thierry.kdev@gmail.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Thomas Gleixner <tglx@linutronix.de>, Jason Cooper <jason@lakedaemon.net>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, Andrew Murray <Andrew.Murray@arm.com>, Zenghui Yu <yuzenghui@huawei.com>, Robert Richter <rrichter@marvell.com>, "Tangnianyao (ICT)" <tangnianyao@huawei.com> Subject: Re: [PATCH v3 29/32] KVM: arm64: GICv4.1: Allow SGIs to switch between HW and SW interrupts Date: Wed, 15 Jan 2020 13:17:24 +0000 [thread overview] Message-ID: <c5d057291e01a1d0b02290504f8ed048@kernel.org> (raw) In-Reply-To: <cc5fe20c-7a0c-c266-e78a-2a85963ab20f@hisilicon.com> On 2020-01-15 02:49, Shaokun Zhang wrote: > Hi Marc, [This is from Nianyao] > > On 2019/12/24 19:10, Marc Zyngier wrote: >> In order to let a guest buy in the new, active-less SGIs, we >> need to be able to switch between the two modes. >> >> Handle this by stopping all guest activity, transfer the state >> from one mode to the other, and resume the guest. >> >> Signed-off-by: Marc Zyngier <maz@kernel.org> >> --- >> include/kvm/arm_vgic.h | 3 ++ >> virt/kvm/arm/vgic/vgic-v3.c | 2 + >> virt/kvm/arm/vgic/vgic-v4.c | 96 >> +++++++++++++++++++++++++++++++++++++ >> virt/kvm/arm/vgic/vgic.h | 1 + >> 4 files changed, 102 insertions(+) >> >> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h >> index 63457908c9c4..69f4164d6477 100644 >> --- a/include/kvm/arm_vgic.h >> +++ b/include/kvm/arm_vgic.h >> @@ -231,6 +231,9 @@ struct vgic_dist { >> /* distributor enabled */ >> bool enabled; >> >> + /* Wants SGIs without active state */ >> + bool nassgireq; >> + >> struct vgic_irq *spis; >> >> struct vgic_io_device dist_iodev; >> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c >> index c2fdea201747..c79a251c4974 100644 >> --- a/virt/kvm/arm/vgic/vgic-v3.c >> +++ b/virt/kvm/arm/vgic/vgic-v3.c >> @@ -540,6 +540,8 @@ int vgic_v3_map_resources(struct kvm *kvm) >> goto out; >> } >> >> + if (kvm_vgic_global_state.has_gicv4_1) >> + vgic_v4_configure_vsgis(kvm); >> dist->ready = true; >> >> out: >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c >> index c2fcde104ea2..063785fd2dc7 100644 >> --- a/virt/kvm/arm/vgic/vgic-v4.c >> +++ b/virt/kvm/arm/vgic/vgic-v4.c >> @@ -97,6 +97,102 @@ static irqreturn_t vgic_v4_doorbell_handler(int >> irq, void *info) >> return IRQ_HANDLED; >> } >> >> +static void vgic_v4_sync_sgi_config(struct its_vpe *vpe, struct >> vgic_irq *irq) >> +{ >> + vpe->sgi_config[irq->intid].enabled = irq->enabled; >> + vpe->sgi_config[irq->intid].group = irq->group; >> + vpe->sgi_config[irq->intid].priority = irq->priority; >> +} >> + >> +static void vgic_v4_enable_vsgis(struct kvm_vcpu *vcpu) >> +{ >> + struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; >> + int i; >> + >> + /* >> + * With GICv4.1, every virtual SGI can be directly injected. So >> + * let's pretend that they are HW interrupts, tied to a host >> + * IRQ. The SGI code will do its magic. >> + */ >> + for (i = 0; i < VGIC_NR_SGIS; i++) { >> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); >> + struct irq_desc *desc; >> + int ret; >> + >> + if (irq->hw) { >> + vgic_put_irq(vcpu->kvm, irq); >> + continue; >> + } >> + >> + irq->hw = true; >> + irq->host_irq = irq_find_mapping(vpe->sgi_domain, i); > > I think we need to check whether irq_find_mapping returns 0. Why? its_alloc_vcpu_sgis() performs the allocation of all 16 SGIs in one go. If that fails, we should error out. Conversely, we're guaranteed that we have a mapping if it hasn't failed. > >> + vgic_v4_sync_sgi_config(vpe, irq); >> + /* >> + * SGIs are initialised as disabled. Enable them if >> + * required by the rest of the VGIC init code. >> + */ >> + desc = irq_to_desc(irq->host_irq); >> + ret = irq_domain_activate_irq(irq_desc_get_irq_data(desc), >> + false); > > If irq->host_irq is not valid , in irq_domain_activate_irq, it will > trigger NULL pointer dereference in host kernel. > I meet a problem here. When hw support GIC4.1, and host kernel is > started with > kvm-arm.vgic_v4_enable=0, starting a virtual machine will trigger NULL > pointer > dereference in host. The following is error info: [...] But the problem here is that we're trying to use GICv4.1 even if GICv4 is disabled. I don't think there is a point in trying to sidestep this locally if we're doing the wrong thing at top-level, which seems to be the case. Thanks, M. -- Jazz is not dead. It just smells funny...
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org> To: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, Jason Cooper <jason@lakedaemon.net>, linux-kernel@vger.kernel.org, Robert Richter <rrichter@marvell.com>, Thomas Gleixner <tglx@linutronix.de>, kvmarm@lists.cs.columbia.edu Subject: Re: [PATCH v3 29/32] KVM: arm64: GICv4.1: Allow SGIs to switch between HW and SW interrupts Date: Wed, 15 Jan 2020 13:17:24 +0000 [thread overview] Message-ID: <c5d057291e01a1d0b02290504f8ed048@kernel.org> (raw) In-Reply-To: <cc5fe20c-7a0c-c266-e78a-2a85963ab20f@hisilicon.com> On 2020-01-15 02:49, Shaokun Zhang wrote: > Hi Marc, [This is from Nianyao] > > On 2019/12/24 19:10, Marc Zyngier wrote: >> In order to let a guest buy in the new, active-less SGIs, we >> need to be able to switch between the two modes. >> >> Handle this by stopping all guest activity, transfer the state >> from one mode to the other, and resume the guest. >> >> Signed-off-by: Marc Zyngier <maz@kernel.org> >> --- >> include/kvm/arm_vgic.h | 3 ++ >> virt/kvm/arm/vgic/vgic-v3.c | 2 + >> virt/kvm/arm/vgic/vgic-v4.c | 96 >> +++++++++++++++++++++++++++++++++++++ >> virt/kvm/arm/vgic/vgic.h | 1 + >> 4 files changed, 102 insertions(+) >> >> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h >> index 63457908c9c4..69f4164d6477 100644 >> --- a/include/kvm/arm_vgic.h >> +++ b/include/kvm/arm_vgic.h >> @@ -231,6 +231,9 @@ struct vgic_dist { >> /* distributor enabled */ >> bool enabled; >> >> + /* Wants SGIs without active state */ >> + bool nassgireq; >> + >> struct vgic_irq *spis; >> >> struct vgic_io_device dist_iodev; >> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c >> index c2fdea201747..c79a251c4974 100644 >> --- a/virt/kvm/arm/vgic/vgic-v3.c >> +++ b/virt/kvm/arm/vgic/vgic-v3.c >> @@ -540,6 +540,8 @@ int vgic_v3_map_resources(struct kvm *kvm) >> goto out; >> } >> >> + if (kvm_vgic_global_state.has_gicv4_1) >> + vgic_v4_configure_vsgis(kvm); >> dist->ready = true; >> >> out: >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c >> index c2fcde104ea2..063785fd2dc7 100644 >> --- a/virt/kvm/arm/vgic/vgic-v4.c >> +++ b/virt/kvm/arm/vgic/vgic-v4.c >> @@ -97,6 +97,102 @@ static irqreturn_t vgic_v4_doorbell_handler(int >> irq, void *info) >> return IRQ_HANDLED; >> } >> >> +static void vgic_v4_sync_sgi_config(struct its_vpe *vpe, struct >> vgic_irq *irq) >> +{ >> + vpe->sgi_config[irq->intid].enabled = irq->enabled; >> + vpe->sgi_config[irq->intid].group = irq->group; >> + vpe->sgi_config[irq->intid].priority = irq->priority; >> +} >> + >> +static void vgic_v4_enable_vsgis(struct kvm_vcpu *vcpu) >> +{ >> + struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; >> + int i; >> + >> + /* >> + * With GICv4.1, every virtual SGI can be directly injected. So >> + * let's pretend that they are HW interrupts, tied to a host >> + * IRQ. The SGI code will do its magic. >> + */ >> + for (i = 0; i < VGIC_NR_SGIS; i++) { >> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); >> + struct irq_desc *desc; >> + int ret; >> + >> + if (irq->hw) { >> + vgic_put_irq(vcpu->kvm, irq); >> + continue; >> + } >> + >> + irq->hw = true; >> + irq->host_irq = irq_find_mapping(vpe->sgi_domain, i); > > I think we need to check whether irq_find_mapping returns 0. Why? its_alloc_vcpu_sgis() performs the allocation of all 16 SGIs in one go. If that fails, we should error out. Conversely, we're guaranteed that we have a mapping if it hasn't failed. > >> + vgic_v4_sync_sgi_config(vpe, irq); >> + /* >> + * SGIs are initialised as disabled. Enable them if >> + * required by the rest of the VGIC init code. >> + */ >> + desc = irq_to_desc(irq->host_irq); >> + ret = irq_domain_activate_irq(irq_desc_get_irq_data(desc), >> + false); > > If irq->host_irq is not valid , in irq_domain_activate_irq, it will > trigger NULL pointer dereference in host kernel. > I meet a problem here. When hw support GIC4.1, and host kernel is > started with > kvm-arm.vgic_v4_enable=0, starting a virtual machine will trigger NULL > pointer > dereference in host. The following is error info: [...] But the problem here is that we're trying to use GICv4.1 even if GICv4 is disabled. I don't think there is a point in trying to sidestep this locally if we're doing the wrong thing at top-level, which seems to be the case. Thanks, M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next prev parent reply other threads:[~2020-01-15 13:17 UTC|newest] Thread overview: 119+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-12-24 11:10 [PATCH v3 00/32] irqchip/gic-v4: GICv4.1 architecture support Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 01/32] irqchip/gic-v3: Detect GICv4.1 supporting RVPEID Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 02/32] irqchip/gic-v3: Add GICv4.1 VPEID size discovery Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 03/32] irqchip/gic-v3: Workaround Cavium TX1 erratum when reading GICD_TYPER2 Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-03-09 22:11 ` Robert Richter 2020-03-09 22:11 ` Robert Richter 2020-03-10 11:41 ` Marc Zyngier 2020-03-10 11:41 ` Marc Zyngier 2020-03-10 12:34 ` Robert Richter 2020-03-10 12:34 ` Robert Richter 2020-03-11 8:45 ` Robert Richter 2020-03-11 8:45 ` Robert Richter 2020-03-11 9:03 ` Marc Zyngier 2020-03-11 9:03 ` Marc Zyngier 2020-03-11 9:18 ` Robert Richter 2020-03-11 9:18 ` Robert Richter 2019-12-24 11:10 ` [PATCH v3 04/32] irqchip/gic-v3: Use SGIs without active state if offered Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-28 8:56 ` Zenghui Yu 2019-12-28 8:56 ` Zenghui Yu 2019-12-28 10:36 ` Marc Zyngier 2019-12-28 10:36 ` Marc Zyngier 2019-12-30 3:50 ` Zenghui Yu 2019-12-30 3:50 ` Zenghui Yu 2019-12-24 11:10 ` [PATCH v3 05/32] irqchip/gic-v4.1: VPE table (aka GICR_VPROPBASER) allocation Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-20 14:03 ` Zenghui Yu 2020-01-20 14:03 ` Zenghui Yu 2020-01-20 15:11 ` Marc Zyngier 2020-01-20 15:11 ` Marc Zyngier 2020-01-22 2:59 ` Zenghui Yu 2020-01-22 2:59 ` Zenghui Yu 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 06/32] irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 07/32] irqchip/gic-v4.1: Don't use the VPE proxy if RVPEID is set Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 08/32] irqchip/gic-v4.1: Implement the v4.1 flavour of VMOVP Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 09/32] irqchip/gic-v4.1: Plumb skeletal VPE irqchip Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 10/32] irqchip/gic-v4.1: Add mask/unmask doorbell callbacks Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 11/32] irqchip/gic-v4.1: Add VPE residency callback Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 12/32] irqchip/gic-v4.1: Add VPE eviction callback Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 13/32] irqchip/gic-v4.1: Add VPE INVALL callback Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 14/32] irqchip/gic-v4.1: Suppress per-VLPI doorbell Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 15/32] irqchip/gic-v4.1: Allow direct invalidation of VLPIs Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-24 19:11 ` [tip: irq/core] " tip-bot2 for Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 16/32] irqchip/gic-v4.1: Advertise support v4.1 to KVM Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 17/32] irqchip/gic-v4.1: Map the ITS SGIR register page Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 18/32] irqchip/gic-v4.1: Plumb skeletal VSGI irqchip Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 19/32] irqchip/gic-v4.1: Add initial SGI configuration Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 20/32] irqchip/gic-v4.1: Plumb mask/unmask SGI callbacks Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 21/32] irqchip/gic-v4.1: Plumb get/set_irqchip_state " Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 22/32] irqchip/gic-v4.1: Plumb set_vcpu_affinity " Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 23/32] irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 24/32] irqchip/gic-v4.1: Add VSGI allocation/teardown Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 25/32] irqchip/gic-v4.1: Add VSGI property setup Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 26/32] irqchip/gic-v4.1: Eagerly vmap vPEs Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 27/32] KVM: arm64: GICv4.1: Let doorbells be auto-enabled Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 28/32] KVM: arm64: GICv4.1: Add direct injection capability to SGI registers Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-28 9:19 ` Zenghui Yu 2019-12-28 9:19 ` Zenghui Yu 2019-12-28 10:41 ` Marc Zyngier 2019-12-28 10:41 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 29/32] KVM: arm64: GICv4.1: Allow SGIs to switch between HW and SW interrupts Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2020-01-15 2:49 ` Shaokun Zhang 2020-01-15 2:49 ` Shaokun Zhang 2020-01-15 3:49 ` Zenghui Yu 2020-01-15 3:49 ` Zenghui Yu 2020-01-15 13:32 ` Marc Zyngier 2020-01-15 13:32 ` Marc Zyngier 2020-01-15 13:49 ` Zenghui Yu 2020-01-15 13:49 ` Zenghui Yu 2020-01-16 6:13 ` Shaokun Zhang 2020-01-16 6:13 ` Shaokun Zhang 2020-01-15 13:17 ` Marc Zyngier [this message] 2020-01-15 13:17 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 30/32] KVM: arm64: GICv4.1: Plumb SGI implementation selection in the distributor Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 31/32] KVM: arm64: GICv4.1: Reload VLPI configuration on distributor enable/disable Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier 2019-12-24 11:10 ` [PATCH v3 32/32] KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs Marc Zyngier 2019-12-24 11:10 ` Marc Zyngier
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