On Thu, Jul 5, 2012 at 11:28 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote:
> Plug the interrupt injection code. Interrupts can now be generated
> from user space.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> arch/arm/include/asm/kvm_vgic.h | 1 +
> arch/arm/kvm/arm.c | 43 ++++++++++++++++++++++++++++--
> arch/arm/kvm/vgic.c | 56 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 98 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h
> index 481f4a9..48c27da 100644
> --- a/arch/arm/include/asm/kvm_vgic.h
> +++ b/arch/arm/include/asm/kvm_vgic.h
> @@ -220,6 +220,7 @@ struct kvm_exit_mmio;
> #ifdef CONFIG_KVM_ARM_VGIC
> void kvm_vgic_sync_to_cpu(struct kvm_vcpu *vcpu);
> void kvm_vgic_sync_from_cpu(struct kvm_vcpu *vcpu);
> +int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, const struct kvm_irq_level *irq);
> int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
> int vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
> struct kvm_exit_mmio *mmio);
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index bdf0f86..7b27a4e 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -654,6 +654,12 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level)
> bool set;
> int bit_nr;
>
> + if (irqchip_in_kernel(kvm)) {
> + if (irq_level->irq < 32)
> + return -EINVAL;
> + return kvm_vgic_inject_irq(kvm, 0, irq_level);
> + }
> +
> vcpu_idx = irq_level->irq >> 1;
> if (vcpu_idx >= KVM_MAX_VCPUS)
> return -EINVAL;
> @@ -696,7 +702,28 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level)
> long kvm_arch_vcpu_ioctl(struct file *filp,
> unsigned int ioctl, unsigned long arg)
> {
> - return -EINVAL;
> + struct kvm_vcpu *vcpu = filp->private_data;
> + void __user *argp = (void __user *)arg;
> +
> + switch (ioctl) {
> +#ifdef CONFIG_KVM_ARM_VGIC
> + case KVM_IRQ_LINE: {
> + struct kvm_irq_level irq_event;
> +
> + if (copy_from_user(&irq_event, argp, sizeof irq_event))
> + return -EFAULT;
> +
> + if (!irqchip_in_kernel(vcpu->kvm))
> + return -EINVAL;
> +
> + if (irq_event.irq < 16 || irq_event.irq >= 32)
> + return -EINVAL;
> + return kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, &irq_event);
> + }
We need to rework this scheme, see the discussion here:
https://patchwork.kernel.org/patch/1149581/
Having an ioctl that can both be a vcpu and a vm ioctl is certainly ugly.
I don't think we should have a vcpu ioctl for this purpose at all for
two reasons 1) this happens asynchronously to the vcpu thread and 2)
even a PPI is semantically not a vcpu operation but an operation on
the gic distributor, which belongs to the VM.
Can't we simply build on what we have and use this scheme:
| 31 30 29 ... 18 17 16 | 15 | 14 13 12 ... 3 2 1 | 0 |
| vcpu index | 0 | SPI / PPI | I=0/F=1 |
For user space gic and PPI:
vcpu_idx = val >> 16;
if (vcpu_idx > online_vcpus)
return -EINVAL;
For user space gic:
bool irq = !(val & 1);
bool fiq = val & 1'
For in-kernel gic:
irq = (val >> 1) & 0x7fff;
if (irq < 16)
return -EINVAL;
> +#endif
> + default:
> + return -EINVAL;
> + }
> }
>
> int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
> @@ -707,7 +734,19 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
> long kvm_arch_vm_ioctl(struct file *filp,
> unsigned int ioctl, unsigned long arg)
> {
> - return -EINVAL;
> + struct kvm *kvm = filp->private_data;
> +
> + switch (ioctl) {
> +#ifdef CONFIG_KVM_ARM_VGIC
> + case KVM_CREATE_IRQCHIP:
> + if (vgic_present)
> + return kvm_vgic_init(kvm);
> + else
> + return -EINVAL;
> +#endif
> + default:
> + return -EINVAL;
> + }
> }
>
> static void cpu_set_vector(void *vector)
> diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
> index 8722efc..4d5d23a 100644
> --- a/arch/arm/kvm/vgic.c
> +++ b/arch/arm/kvm/vgic.c
> @@ -69,6 +69,7 @@
> #define ACCESS_WRITE_MASK(x) ((x) & (3 << 1))
>
> static void vgic_update_state(struct kvm *kvm);
> +static void vgic_kick_vcpus(struct kvm *kvm);
> static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
>
> static inline int vgic_irq_is_edge(struct vgic_dist *dist, int irq)
> @@ -500,6 +501,8 @@ int vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_exit
> kvm_handle_mmio_return(vcpu, run);
> spin_unlock(&vcpu->kvm->arch.vgic.lock);
>
> + vgic_kick_vcpus(vcpu->kvm);
> +
> return KVM_EXIT_UNKNOWN;
> }
>
> @@ -795,3 +798,56 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
>
> return test_bit(1 << vcpu->vcpu_id, &dist->irq_pending_on_cpu);
> }
> +
> +static void vgic_kick_vcpus(struct kvm *kvm)
> +{
> + struct kvm_vcpu *vcpu;
> + int c;
> +
> + /*
> + * We've injected an interrupt, time to find out who deserves
> + * a good kick...
> + */
> + kvm_for_each_vcpu(c, vcpu, kvm) {
> + if (kvm_vgic_vcpu_pending_irq(vcpu)) {
> + vcpu->arch.wait_for_interrupts = 0;
> + kvm_vcpu_kick(vcpu);
> + }
> + }
> +}
> +
> +int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, const struct kvm_irq_level *irq)
> +{
> + struct vgic_dist *dist = &kvm->arch.vgic;
> + int nrcpus = atomic_read(&kvm->online_vcpus);
> + int is_edge, state;
> +
> + if (cpuid >= nrcpus)
> + return -EINVAL;
> +
> + /* Only PPIs or SPIs */
> + if (irq->irq >= VGIC_NR_IRQS || irq->irq < 16)
> + return -EINVAL;
> +
> + kvm_debug("Inject IRQ%d\n", irq->irq);
> + spin_lock(&dist->lock);
> + is_edge = vgic_irq_is_edge(dist, irq->irq);
> + state = vgic_bitmap_get_irq_val(&dist->irq_state, cpuid, irq->irq);
> +
> + /*
> + * Inject an interrupt if:
> + * - level triggered and we change level
> + * - edge triggered and we have a rising edge
> + */
> + if ((!is_edge && (state ^ !!irq->level)) ||
> + (is_edge && !state && irq->level)) {
> + vgic_bitmap_set_irq_val(&dist->irq_state, cpuid,
> + irq->irq, !!irq->level);
> + vgic_update_state(kvm);
> + }
> + spin_unlock(&dist->lock);
> +
> + vgic_kick_vcpus(kvm);
do we need this if we don't call vgic_update_state?
> +
> + return 0;
> +}
> --
> 1.7.10.3
>
>
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