[PATCH v3 9/9] KVM: arm/arm64: Don't assume initialized vgic when setting PMU IRQ

Christoffer Dall
2017-06-08T13:30:57Z

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@linaro.org>
---
include/kvm/arm_vgic.h | 2 ++
virt/kvm/arm/pmu.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 131668f..a2ae9d2 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 26a42a9..87cb325 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -547,7 +547,7 @@ 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))
--
2.9.0