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

From: [email-masked] (Andre Przywara)
Date: Tue, 3 May 2016 11:09:12 +0100

Hi,

On 03/05/16 10:59, Marc Zyngier wrote:
> 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.

It is implemented in patch 46/54.
Shall I remove the TODO to avoid confusion and/or replace it with a note
either in a comment or in this commit message that the implementation
will follow in one the next patches?

Cheers,
Andre.