Re: [PATCH 6/8] KVM: assigned dev: Preparation for mask support in userspace

[Avi Kivity <avi@redhat.com>]

  On 10/20/2010 10:26 AM, Sheng Yang wrote:
> The feature wouldn't be enabled until later patch set msix_flags_enabled. It
> would be enabled along with mask support in kernel.
>
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index e209078..2bb69ba 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -456,6 +456,8 @@ struct kvm_arch {
>   	/* fields used by HYPER-V emulation */
>   	u64 hv_guest_os_id;
>   	u64 hv_hypercall;
> +
> +	bool msix_flags_enabled;
>   };

In theory this should be in generic code, under #ifdef 
KVM_APIC_ARCHITECTURE.  In practice x86 is fine since ia64 isn't 
actively developed.

> @@ -666,11 +666,35 @@ msix_nr_out:
>   	return r;
>   }
>
> +static void update_msix_mask(struct kvm_assigned_dev_kernel *assigned_dev,
> +			     int index)
> +{
> +	int irq;
> +	struct irq_desc *desc;
> +
> +	if (!assigned_dev->dev->msix_enabled ||
> +	    !(assigned_dev->irq_requested_type&  KVM_DEV_IRQ_HOST_MSIX))
> +		return;
> +
> +	irq = assigned_dev->host_msix_entries[index].vector;
> +	BUG_ON(irq == 0);
> +	desc = irq_to_desc(irq);
> +	BUG_ON(!desc->msi_desc);
> +
> +	if (assigned_dev->guest_msix_entries[index].flags&
> +			KVM_ASSIGNED_MSIX_MASK) {
> +		desc->chip->mask(irq);
> +		flush_work(&assigned_dev->interrupt_work);
> +	} else
> +		desc->chip->unmask(irq);
> +}
> +
>   static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
>   				       struct kvm_assigned_msix_entry *entry)
>   {
>   	int r = 0, i;
>   	struct kvm_assigned_dev_kernel *adev;
> +	bool entry_masked;
>
>   	mutex_lock(&kvm->lock);
>
> @@ -688,6 +712,21 @@ static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
>   			adev->guest_msix_entries[i].entry = entry->entry;
>   			adev->guest_msix_entries[i].vector = entry->gsi;
>   			adev->host_msix_entries[i].entry = entry->entry;
> +			if (!kvm->arch.msix_flags_enabled)
> +				break;
> +			entry_masked = adev->guest_msix_entries[i].flags&
> +				KVM_ASSIGNED_MSIX_MASK;
> +			if ((entry->flags&  KVM_MSIX_FLAG_MASK)&&
> +					!entry_masked) {
> +				adev->guest_msix_entries[i].flags |=
> +					KVM_ASSIGNED_MSIX_MASK;
> +				update_msix_mask(adev, i);
> +			} else if (!(entry->flags&  KVM_MSIX_FLAG_MASK)&&
> +					entry_masked) {
> +				adev->guest_msix_entries[i].flags&=
> +					~KVM_ASSIGNED_MSIX_MASK;
> +				update_msix_mask(adev, i);
> +			}
>   			break;
>   		}

I think you can fold these two functions together, will get rid of the 
extra if and be a little more readable.

-- 
error compiling committee.c: too many arguments to function