Subject: [PATCH v2 7/7] KVM: arm: implement kvm_set_msi by gsi direct mapping

From: [email-masked] (Eric Auger)
Date: Fri, 31 Jul 2015 14:59:54 +0200

Hi Andre,
On 07/11/2015 01:17 AM, Andre Przywara wrote:
> On 09/07/15 09:22, 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 for arm too.
>>
>> Signed-off-by: Eric Auger <[email-masked]>
>>
>> ---
>>
>> v1 -> v2:
>> - introduce vgic_v2m_inject_msi in vgic-v2-emul.c following Andre's
>>   advice
>> ---
>>  arch/arm/kvm/Kconfig        |  1 +
>>  virt/kvm/arm/vgic-v2-emul.c | 12 ++++++++++++
>>  2 files changed, 13 insertions(+)
>>
>> diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
>> index 151e710..0f58baf 100644
>> --- a/arch/arm/kvm/Kconfig
>> +++ b/arch/arm/kvm/Kconfig
>> @@ -31,6 +31,7 @@ config KVM
>>  	select KVM_VFIO
>>  	select HAVE_KVM_EVENTFD
>>  	select HAVE_KVM_IRQFD
>> +	select HAVE_KVM_MSI
> 
> I wonder if this requires some more code to only advertise
> KVM_CAP_SIGNAL_MSI if userland actually sets up a GICv2M?
> Otherwise userland could get the idea of being able to inectj MSIs
> without the guest actually being prepared for that (because the GICv2M
> driver did not initialize).
Not sure I get what you mean here. By directly transforming the user
provided MSI msg into an SPI ID, do we really have to care about GICv2M?

Best Regards

Eric
> 
> Cheers,
> Andre.
> 
>>  	select HAVE_KVM_IRQCHIP
>>  	select HAVE_KVM_IRQ_ROUTING
>>  	depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER
>> diff --git a/virt/kvm/arm/vgic-v2-emul.c b/virt/kvm/arm/vgic-v2-emul.c
>> index 1390797..43013cc 100644
>> --- a/virt/kvm/arm/vgic-v2-emul.c
>> +++ b/virt/kvm/arm/vgic-v2-emul.c
>> @@ -478,6 +478,17 @@ static bool vgic_v2_queue_sgi(struct kvm_vcpu *vcpu, int irq)
>>  }
>>  
>>  /**
>> + * Emulates GICv2M MSI injection by injecting the SPI ID matching
>> + * the msi data
>> + * @kvm: pointer to the kvm struct
>> + * @msi: the msi struct handle
>> + */
>> +static int vgic_v2m_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
>> +{
>> +	return kvm_vgic_inject_irq(kvm, 0, msi->data, 1);
>> +}
>> +
>> +/**
>>   * kvm_vgic_map_resources - Configure global VGIC state before running any VCPUs
>>   * @kvm: pointer to the kvm struct
>>   *
>> @@ -566,6 +577,7 @@ void vgic_v2_init_emulation(struct kvm *kvm)
>>  	dist->vm_ops.add_sgi_source = vgic_v2_add_sgi_source;
>>  	dist->vm_ops.init_model = vgic_v2_init_model;
>>  	dist->vm_ops.map_resources = vgic_v2_map_resources;
>> +	dist->vm_ops.inject_msi = vgic_v2m_inject_msi;
>>  
>>  	kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
>>  }
>>
>