Re: [PATCH 09/12] KVM: arm/arm64: prepare GICv2 emulation to be handled by kvm_io_bus

Christoffer Dall
2015-03-14T14:30:44Z

On Fri, Mar 13, 2015 at 04:10:09PM +0000, Andre Przywara wrote:
> Using the framework provided by the recent vgic.c changes we register
> a kvm_io_bus device when initializing the virtual GICv2.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> include/kvm/arm_vgic.h | 1 +
> virt/kvm/arm/vgic-v2-emul.c | 13 +++++++++----
> virt/kvm/arm/vgic.c | 16 ++++++++++++++++
> 3 files changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 4bfc6a3..74a4ac4 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -245,6 +245,7 @@ struct vgic_dist {
> unsigned long *irq_pending_on_cpu;
>
> struct vgic_vm_ops vm_ops;
> + struct vgic_io_device dist_iodev;
> };
>
> struct vgic_v2_cpu_if {
> diff --git a/virt/kvm/arm/vgic-v2-emul.c b/virt/kvm/arm/vgic-v2-emul.c
> index 0defac6..6f685c9 100644
> --- a/virt/kvm/arm/vgic-v2-emul.c
> +++ b/virt/kvm/arm/vgic-v2-emul.c
> @@ -490,6 +490,7 @@ static bool vgic_v2_queue_sgi(struct kvm_vcpu *vcpu, int irq)
> static int vgic_v2_map_resources(struct kvm *kvm,
> const struct vgic_params *params)
> {
> + struct vgic_dist *dist = &kvm->arch.vgic;
> int ret = 0;
>
> if (!irqchip_in_kernel(kvm))
> @@ -500,13 +501,17 @@ static int vgic_v2_map_resources(struct kvm *kvm,
> if (vgic_ready(kvm))
> goto out;
>
> - if (IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_dist_base) ||
> - IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_cpu_base)) {
> + if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) ||
> + IS_VGIC_ADDR_UNDEF(dist->vgic_cpu_base)) {
> kvm_err("Need to set vgic cpu and dist addresses first\n");
> ret = -ENXIO;
> goto out;
> }
>
> + vgic_register_kvm_io_dev(kvm, dist->vgic_dist_base,
> + KVM_VGIC_V2_DIST_SIZE,
> + vgic_dist_ranges, -1, &dist->dist_iodev);
> +
> /*
> * Initialize the vgic if this hasn't already been done on demand by
> * accessing the vgic state from userspace.
> @@ -517,7 +522,7 @@ static int vgic_v2_map_resources(struct kvm *kvm,
> goto out;
> }
>
> - ret = kvm_phys_addr_ioremap(kvm, kvm->arch.vgic.vgic_cpu_base,
> + ret = kvm_phys_addr_ioremap(kvm, dist->vgic_cpu_base,
> params->vcpu_base, KVM_VGIC_V2_CPU_SIZE,
> true);
> if (ret) {
> @@ -525,7 +530,7 @@ static int vgic_v2_map_resources(struct kvm *kvm,
> goto out;
> }
>
> - kvm->arch.vgic.ready = true;
> + dist->ready = true;
> out:
> if (ret)
> kvm_vgic_destroy(kvm);
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index 71389b8..b1dd717 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -908,6 +908,20 @@ int vgic_register_kvm_io_dev(struct kvm *kvm, gpa_t base, int len,
> return 0;
> }
>
> +static void vgic_unregister_kvm_io_dev(struct kvm *kvm)
> +{
> + struct vgic_dist *dist = &kvm->arch.vgic;
> +
> + if (!dist || !kvm->buses[KVM_MMIO_BUS])
> + return;
> +
> + mutex_lock(&kvm->slots_lock);
> + if (dist->dist_iodev.dev.ops)
> + kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
> + &dist->dist_iodev.dev);

why are we only unregisttering the iodev when we have ops?

> + mutex_unlock(&kvm->slots_lock);
> +}
> +
> static int vgic_nr_shared_irqs(struct vgic_dist *dist)
> {
> return dist->nr_irqs - VGIC_NR_PRIVATE_IRQS;
> @@ -1546,6 +1560,8 @@ void kvm_vgic_destroy(struct kvm *kvm)
> struct kvm_vcpu *vcpu;
> int i;
>
> + vgic_unregister_kvm_io_dev(kvm);
> +
> kvm_for_each_vcpu(i, vcpu, kvm)
> kvm_vgic_vcpu_destroy(vcpu);
>
> --
> 1.7.9.5
>