Re: [PATCH 7/8] KVM: arm/arm64: Register ITS iodev when setting base address

Auger Eric
2017-05-08T17:12:27Z

Hi,

On 08/05/2017 13:54, Christoffer Dall wrote:
> We have to register the ITS iodevice before running the VM, because in
> migration scenarios, we may be restoring a live device that wishes to
> inject MSIs before we get a chance to run the VM.

actually the VM is in running state but the vcpus has not yet started.
>
> All we need to register the ITS io device is the base address of the
> ITS, so we can simply register that when the base address of the ITS is
> set.
>
> Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric
> ---
> virt/kvm/arm/vgic/vgic-its.c | 29 +----------------------------
> virt/kvm/arm/vgic/vgic-v3.c | 8 --------
> virt/kvm/arm/vgic/vgic.h | 1 -
> 3 files changed, 1 insertion(+), 37 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 9f7105c..375c503 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -2390,7 +2390,7 @@ static int vgic_its_set_attr(struct kvm_device *dev,
>
> its->vgic_its_base = addr;
>
> - return 0;
> + return vgic_register_its_iodev(dev->kvm, its);
> }
> case KVM_DEV_ARM_VGIC_GRP_CTRL: {
> const struct vgic_its_abi *abi = vgic_its_get_abi(its);
> @@ -2467,30 +2467,3 @@ int kvm_vgic_register_its_device(void)
> return kvm_register_device_ops(&kvm_arm_vgic_its_ops,
> KVM_DEV_TYPE_ARM_VGIC_ITS);
> }
> -
> -/*
> - * Registers all ITSes with the kvm_io_bus framework.
> - * To follow the existing VGIC initialization sequence, this has to be
> - * done as late as possible, just before the first VCPU runs.
> - */
> -int vgic_register_its_iodevs(struct kvm *kvm)
> -{
> - struct kvm_device *dev;
> - int ret = 0;
> -
> - list_for_each_entry(dev, &kvm->devices, vm_node) {
> - if (dev->ops != &kvm_arm_vgic_its_ops)
> - continue;
> -
> - ret = vgic_register_its_iodev(kvm, dev->private);
> - if (ret)
> - return ret;
> - /*
> - * We don't need to care about tearing down previously
> - * registered ITSes, as the kvm_io_bus framework removes
> - * them for us if the VM gets destroyed.
> - */
> - }
> -
> - return ret;
> -}
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 4d51d1f..d77fcb3 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -396,14 +396,6 @@ int vgic_v3_map_resources(struct kvm *kvm)
> goto out;
> }
>
> - if (vgic_has_its(kvm)) {
> - ret = vgic_register_its_iodevs(kvm);
> - if (ret) {
> - kvm_err("Unable to register VGIC ITS MMIO regions\n");
> - goto out;
> - }
> - }
> -
> dist->ready = true;
>
> out:
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 5f17eac..8ac7397 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -181,7 +181,6 @@ bool vgic_v3_check_base(struct kvm *kvm);
> void vgic_v3_load(struct kvm_vcpu *vcpu);
> void vgic_v3_put(struct kvm_vcpu *vcpu);
>
> -int vgic_register_its_iodevs(struct kvm *kvm);
> bool vgic_has_its(struct kvm *kvm);
> int kvm_vgic_register_its_device(void);
> void vgic_enable_lpis(struct kvm_vcpu *vcpu);
>