Subject: [PATCH v2 42/54] KVM: arm/arm64: vgic-new: vgic_kvm_device: access to VGIC registers

From: [email-masked] (Marc Zyngier)
Date: Tue, 3 May 2016 10:59:13 +0100

On 28/04/16 17:46, Andre Przywara wrote:
> From: Eric Auger <[email-masked]>
> 
> This patch implements the switches for KVM_DEV_ARM_VGIC_GRP_DIST_REGS
> and KVM_DEV_ARM_VGIC_GRP_CPU_REGS API which allows the userspace to
> access VGIC registers.
> 
> At that stage the interfaces with the MMIO API are not implemented:
> - vgic_attr_regs_access
> - vgic_v2_has_attr_regs
> 
> Signed-off-by: Eric Auger <[email-masked]>
> Signed-off-by: Andre Przywara <[email-masked]>
> ---
>  virt/kvm/arm/vgic/vgic-kvm-device.c | 53 +++++++++++++++++++++++++++++++++++--
>  virt/kvm/arm/vgic/vgic-mmio-v2.c    | 34 ++++++++++++++++++++++++
>  virt/kvm/arm/vgic/vgic.h            |  1 +
>  3 files changed, 86 insertions(+), 2 deletions(-)
> 

[...]

> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
> index ae6077e..f2a8efe 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
> @@ -276,3 +276,37 @@ int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
>  
>  	return ret;
>  }
> +
> +int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
> +{
> +	int nr_irqs = dev->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
> +	const struct vgic_register_region *regions;
> +	gpa_t addr;
> +	int nr_regions, i, len;
> +
> +	addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
> +
> +	switch (attr->group) {
> +	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
> +		regions = vgic_v2_dist_registers;
> +		nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
> +		break;
> +	case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
> +		return -ENXIO;		/* TODO: describe CPU i/f regs also */

This definitely needs addressing, as it breaks guest migration.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...