[PATCH 26/58] KVM: arm/arm64: Don't assume initialized vgic when setting PMU IRQ
Marc Zyngier
marc.zyngier at arm.com
Fri Jun 30 01:44:42 PDT 2017
From: Christoffer Dall <cdall at linaro.org>
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 <cdall at linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>
---
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))
--
2.11.0
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