Re: [PATCH v4 7/7] KVM: arm: enable KVM_SIGNAL_MSI and MSI routing

[Eric Auger <eric.auger@linaro.org>]

On 04/14/2016 02:12 PM, Christoffer Dall wrote:
> On Mon, Apr 04, 2016 at 10:47:37AM +0200, Eric Auger wrote:
>> If the ITS modality is not available, let's simply support MSI
>> injection by transforming the MSI.data into an SPI ID.
>>
>> This becomes possible to use KVM_SIGNAL_MSI ioctl and MSI
>> routing for arm too.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>
>> ---
>>
>> v2 -> v3:
>> - reword the commit message
>> - add sanity check about devid provision
>>
>> v1 -> v2:
>> - introduce vgic_v2m_inject_msi in vgic-v2-emul.c following Andre's
>>   advice
>>
>> Conflicts:
>> 	arch/arm/kvm/Kconfig
>>
>> Conflicts:
>> 	arch/arm/kvm/Kconfig
>> ---
>>  arch/arm/kvm/Kconfig           |  1 +
>>  virt/kvm/arm/vgic/vgic-v2.c    | 15 +++++++++++++++
>>  virt/kvm/arm/vgic/vgic.h       |  1 +
>>  virt/kvm/arm/vgic/vgic_irqfd.c |  2 +-
>>  4 files changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
>> index 92c3aec..67019e5 100644
>> --- a/arch/arm/kvm/Kconfig
>> +++ b/arch/arm/kvm/Kconfig
>> @@ -50,6 +50,7 @@ config KVM_NEW_VGIC
>>  	bool "New VGIC implementation"
>>  	depends on KVM
>>  	default y
>> +	select HAVE_KVM_MSI
>>  	select HAVE_KVM_IRQCHIP
>>  	select HAVE_KVM_IRQ_ROUTING
>>  	---help---
>> diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
>> index 5f7c289..7400af0 100644
>> --- a/virt/kvm/arm/vgic/vgic-v2.c
>> +++ b/virt/kvm/arm/vgic/vgic-v2.c
>> @@ -248,6 +248,21 @@ void vgic_v2_enable(struct kvm_vcpu *vcpu)
>>  	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr = GICH_HCR_EN;
>>  }
>>  
>> +/**
>> + * vgic_v2m_inject_msi: emulates GICv2M MSI injection by injecting
>> + * the SPI ID matching the msi data
>> + *
>> + * @kvm: pointer to the kvm struct
>> + * @msi: the msi struct handle
>> + */
>> +int vgic_v2m_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
>> +{
>> +	if (msi->flags & KVM_MSI_VALID_DEVID)
>> +		return -EINVAL;
>> +
>> +	return kvm_vgic_inject_irq(kvm, 0, msi->data, 1);
> 
> I think you need to validate the msi->data here, otherwise
> vgic_get_irq() is going to raise warnings etc.
OK will check it is within the SPI ID range.

Thank you for your time!

Best Regards

Eric


> 
>> +}
>> +
>>  int vgic_v2_map_resources(struct kvm *kvm)
>>  {
>>  	struct vgic_dist *dist = &kvm->arch.vgic;
>> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
>> index 223c778..354a865 100644
>> --- a/virt/kvm/arm/vgic/vgic.h
>> +++ b/virt/kvm/arm/vgic/vgic.h
>> @@ -44,6 +44,7 @@ int vgic_v2_probe(struct device_node *vgic_node);
>>  int vgic_v2_map_resources(struct kvm *kvm);
>>  int vgic_register_dist_regions(struct kvm *kvm, gpa_t dist_base_address,
>>  			       enum vgic_type);
>> +int vgic_v2m_inject_msi(struct kvm *kvm, struct kvm_msi *msi);
>>  
>>  #ifdef CONFIG_KVM_ARM_VGIC_V3
>>  void vgic_v3_irq_change_affinity(struct kvm *kvm, u32 intid, u64 mpidr);
>> diff --git a/virt/kvm/arm/vgic/vgic_irqfd.c b/virt/kvm/arm/vgic/vgic_irqfd.c
>> index a3a7f02..588cdd6 100644
>> --- a/virt/kvm/arm/vgic/vgic_irqfd.c
>> +++ b/virt/kvm/arm/vgic/vgic_irqfd.c
>> @@ -100,7 +100,7 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
>>  	msi.devid = e->devid;
>>  
>>  	if (!vgic_has_its(kvm))
>> -		return -ENODEV;
>> +		return vgic_v2m_inject_msi(kvm, &msi);
>>  
>>  	return vits_inject_msi(kvm, &msi);
>>  }
>> -- 
>> 1.9.1
>>