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

Avi Kivity
2010-10-20T09:30:51Z

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