[PATCH 15/19] KVM: arm64: vgic-v2: Add helper for legacy dist/cpuif base address setting

[Reiji Watanabe]

Hi Marc,

On Wed, Jul 6, 2022 at 10:05 AM Marc Zyngier <maz at kernel.org> wrote:
>
> We carry a legacy interface to set the base addresses for GICv2.
> As this is currently plumbed into the same handling code as
> the modern interface, it limits the evolution we can make there.
>
> Add a helper dedicated to this handling, with a view of maybe
> removing this in the future.
>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
>  arch/arm64/kvm/arm.c                  | 11 ++-------
>  arch/arm64/kvm/vgic/vgic-kvm-device.c | 32 +++++++++++++++++++++++++++
>  include/kvm/arm_vgic.h                |  1 +
>  3 files changed, 35 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 83a7f61354d3..bf39570c0aef 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1414,18 +1414,11 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
>  static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
>                                         struct kvm_arm_device_addr *dev_addr)
>  {
> -       unsigned long dev_id, type;
> -
> -       dev_id = (dev_addr->id & KVM_ARM_DEVICE_ID_MASK) >>
> -               KVM_ARM_DEVICE_ID_SHIFT;
> -       type = (dev_addr->id & KVM_ARM_DEVICE_TYPE_MASK) >>
> -               KVM_ARM_DEVICE_TYPE_SHIFT;
> -
> -       switch (dev_id) {
> +       switch (FIELD_GET(KVM_ARM_DEVICE_ID_MASK, dev_addr->id)) {
>         case KVM_ARM_DEVICE_VGIC_V2:
>                 if (!vgic_present)
>                         return -ENXIO;
> -               return kvm_vgic_addr(kvm, type, &dev_addr->addr, true);
> +               return kvm_set_legacy_vgic_v2_addr(kvm, dev_addr);
>         default:
>                 return -ENODEV;
>         }
> diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
> index fbbd0338c782..0dfd277b9058 100644
> --- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
> +++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
> @@ -41,6 +41,38 @@ static int vgic_check_type(struct kvm *kvm, int type_needed)
>                 return 0;
>  }
>
> +int kvm_set_legacy_vgic_v2_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev_addr)
> +{
> +       struct vgic_dist *vgic = &kvm->arch.vgic;
> +       int r;
> +
> +       mutex_lock(&kvm->lock);
> +       switch (FIELD_GET(KVM_ARM_DEVICE_ID_MASK, dev_addr->id)) {

Shouldn't this be KVM_ARM_DEVICE_TYPE_MASK (not KVM_ARM_DEVICE_ID_MASK) ?

Thank you,
Reiji


> +       case KVM_VGIC_V2_ADDR_TYPE_DIST:
> +               r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
> +               if (!r)
> +                       r = vgic_check_iorange(kvm, vgic->vgic_dist_base, dev_addr->addr,
> +                                              SZ_4K, KVM_VGIC_V2_DIST_SIZE);
> +               if (!r)
> +                       vgic->vgic_dist_base = dev_addr->addr;
> +               break;
> +       case KVM_VGIC_V2_ADDR_TYPE_CPU:
> +               r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
> +               if (!r)
> +                       r = vgic_check_iorange(kvm, vgic->vgic_cpu_base, dev_addr->addr,
> +                                              SZ_4K, KVM_VGIC_V2_CPU_SIZE);
> +               if (!r)
> +                       vgic->vgic_cpu_base = dev_addr->addr;
> +               break;
> +       default:
> +               r = -ENODEV;
> +       }
> +
> +       mutex_unlock(&kvm->lock);
> +
> +       return r;
> +}
> +
>  /**
>   * kvm_vgic_addr - set or get vgic VM base addresses
>   * @kvm:   pointer to the vm struct
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 2d8f2e90edc2..f79cce67563e 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -365,6 +365,7 @@ extern struct static_key_false vgic_v2_cpuif_trap;
>  extern struct static_key_false vgic_v3_cpuif_trap;
>
>  int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
> +int kvm_set_legacy_vgic_v2_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev_addr);
>  void kvm_vgic_early_init(struct kvm *kvm);
>  int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
>  int kvm_vgic_create(struct kvm *kvm, u32 type);
> --
> 2.34.1
>
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