From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [PATCH v2 42/54] KVM: arm/arm64: vgic-new: vgic_kvm_device:
 access to VGIC registers
Date: Tue, 3 May 2016 10:59:13 +0100
Message-ID: <57287671.3000902@arm.com>
References: <1461861973-26464-1-git-send-email-andre.przywara@arm.com>
 <1461861973-26464-43-git-send-email-andre.przywara@arm.com>
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Cc: Eric Auger <eric.auger@linaro.org>, kvmarm@lists.cs.columbia.edu,
	kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
To: Andre Przywara <andre.przywara@arm.com>,
	Christoffer Dall <christoffer.dall@linaro.org>
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On 28/04/16 17:46, Andre Przywara wrote:
> From: Eric Auger <eric.auger@linaro.org>
> 
> 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 <eric.auger@linaro.org>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  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...