From ebb127f2d6f32665643165289151bd20929d9931 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Tue, 16 May 2017 19:53:50 +0200 Subject: [PATCH] KVM: arm/arm64: Don't assume initialized vgic when setting PMU IRQ The PMU IRQ number is set through the VCPU device's KVM_SET_DEVICE_ATTR ioctl handler for the KVM_ARM_VCPU_PMU_V3_IRQ attribute, but there is no enforced or stated requirement that this must happen after initializing the VGIC. As a result, calling vgic_valid_spi() which relies on the nr_spis being set during the VGIC init can incorrectly fail. Introduce irq_is_spi, which determines if an IRQ number is within the SPI range without verifying it against the actual VGIC properties. Signed-off-by: Christoffer Dall Reviewed-by: Marc Zyngier --- include/kvm/arm_vgic.h | 2 ++ virt/kvm/arm/pmu.c | 22 ++++++++++++++++++---- 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 131668f8599c..a2ae9d2de21f 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -39,6 +39,8 @@ #define KVM_IRQCHIP_NUM_PINS (1020 - 32) #define irq_is_ppi(irq) ((irq) >= VGIC_NR_SGIS && (irq) < VGIC_NR_PRIVATE_IRQS) +#define irq_is_spi(irq) ((irq) >= VGIC_NR_PRIVATE_IRQS && \ + (irq) <= VGIC_MAX_SPI) enum vgic_type { VGIC_V2, /* Good ol' GICv2 */ diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 9923eb90cdc7..fc8a723ff387 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -458,10 +458,24 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu) /* * A valid interrupt configuration for the PMU is either to have a * properly configured interrupt number and using an in-kernel - * irqchip, or to neither set an IRQ nor create an in-kernel irqchip. + * irqchip, or to not have an in-kernel GIC and not set an IRQ. */ - if (kvm_arm_pmu_irq_initialized(vcpu) != irqchip_in_kernel(vcpu->kvm)) - return -EINVAL; + if (irqchip_in_kernel(vcpu->kvm)) { + int irq = vcpu->arch.pmu.irq_num; + if (!kvm_arm_pmu_irq_initialized(vcpu)) + return -EINVAL; + + /* + * If we are using an in-kernel vgic, at this point we know + * the vgic will be initialized, so we can check the PMU irq + * number against the dimensions of the vgic and make sure + * it's valid. + */ + if (!irq_is_ppi(irq) && !vgic_valid_spi(vcpu->kvm, irq)) + return -EINVAL; + } else if (kvm_arm_pmu_irq_initialized(vcpu)) { + return -EINVAL; + } kvm_pmu_vcpu_reset(vcpu); vcpu->arch.pmu.ready = true; @@ -547,7 +561,7 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) return -EFAULT; /* The PMU overflow interrupt can be a PPI or a valid SPI. */ - if (!(irq_is_ppi(irq) || vgic_valid_spi(vcpu->kvm, irq))) + if (!(irq_is_ppi(irq) || irq_is_spi(irq))) return -EINVAL; if (!pmu_irq_is_valid(vcpu->kvm, irq)) -- 2.20.1