diff options
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-kvm-device.c | 55 |
1 files changed, 54 insertions, 1 deletions
diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c index 78621283a301..9ee27cb5842b 100644 --- a/virt/kvm/arm/vgic/vgic-kvm-device.c +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c @@ -238,7 +238,60 @@ static int vgic_attr_regs_access(struct kvm_device *dev, struct kvm_device_attr *attr, u32 *reg, bool is_write) { - return -ENXIO; + gpa_t addr; + int cpuid, ret, c; + struct kvm_vcpu *vcpu, *tmp_vcpu; + int vcpu_lock_idx = -1; + + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >> + KVM_DEV_ARM_VGIC_CPUID_SHIFT; + vcpu = kvm_get_vcpu(dev->kvm, cpuid); + addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + + mutex_lock(&dev->kvm->lock); + + ret = vgic_init(dev->kvm); + if (ret) + goto out; + + if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) { + ret = -EINVAL; + goto out; + } + + /* + * Any time a vcpu is run, vcpu_load is called which tries to grab the + * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure + * that no other VCPUs are run and fiddle with the vgic state while we + * access it. + */ + ret = -EBUSY; + kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) { + if (!mutex_trylock(&tmp_vcpu->mutex)) + goto out; + vcpu_lock_idx = c; + } + + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: + ret = -EINVAL; + break; + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg); + break; + default: + ret = -EINVAL; + break; + } + +out: + for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) { + tmp_vcpu = kvm_get_vcpu(dev->kvm, vcpu_lock_idx); + mutex_unlock(&tmp_vcpu->mutex); + } + + mutex_unlock(&dev->kvm->lock); + return ret; } /* V2 ops */ |