Re: [PATCH v2 2/2] virtio-iommu-pci: force virtio version 1

[Auger Eric]

Hi Connie,

On 9/18/20 11:29 AM, Cornelia Huck wrote:
> On Tue,  8 Sep 2020 21:33:09 +0200
> Eric Auger <eric.auger@redhat.com> wrote:
> 
>> Commit 9b3a35ec82 ("virtio: verify that legacy support is not
>> accidentally on") added a safety check that requires to set
>> 'disable-legacy=on' on virtio-iommu-pci:
>>
>> qemu-system-aarch64: -device virtio-iommu-pci: device is modern-only,
>> use disable-legacy=on
>>
>> virtio-iommu was introduced after the release of VIRTIO 1.0
>> specifications, so it should be 'modern-only'.
>>
>> This patch forces virtio version 1 and removes the 'transitional_name'
>> property removing the need to specify 'disable-legacy=on' on
>> virtio-iommu-pci device.
> 
> Not sure whether this patch has been queued already, and how much we
> care about migration compatibility for virtio-iommu, but would it make
> sense to force modern on 5.1+ compat machines only? (see
> 20200918074710.27810-1-sgarzare@redhat.com/">https://lore.kernel.org/qemu-devel/20200918074710.27810-1-sgarzare@redhat.com/)

I don't think it was pulled yet.
> 
>>
>> Cc: qemu-stable@nongnu.org

The virtio-iommu-pci device only is usable on ARM in dt mode so I don't
think it has production users at the moment.

Thanks

Eric
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>
>> ---
>> v1 -> v2:
>> - Added Connie's R-b
>> ---
>>  hw/virtio/virtio-iommu-pci.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/virtio/virtio-iommu-pci.c b/hw/virtio/virtio-iommu-pci.c
>> index ba62d60a0a..3b6f7a11c6 100644
>> --- a/hw/virtio/virtio-iommu-pci.c
>> +++ b/hw/virtio/virtio-iommu-pci.c
>> @@ -68,6 +68,7 @@ static void virtio_iommu_pci_realize(VirtIOPCIProxy 
>> *vpci_dev, Error **errp)
>>      object_property_set_link(OBJECT(dev), "primary-bus",
>>                               OBJECT(pci_get_bus(&vpci_dev->pci_dev)),
>>                               &error_abort);
>> +    virtio_pci_force_virtio_1(vpci_dev);
>>      qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
>>  }
>>  
>> @@ -97,7 +98,6 @@ static void virtio_iommu_pci_instance_init(Object *obj)
>>  static const VirtioPCIDeviceTypeInfo virtio_iommu_pci_info = {
>>      .base_name             = TYPE_VIRTIO_IOMMU_PCI,
>>      .generic_name          = "virtio-iommu-pci",
>> -    .transitional_name     = "virtio-iommu-pci-transitional",
>>      .non_transitional_name = "virtio-iommu-pci-non-transitional",
>>      .instance_size = sizeof(VirtIOIOMMUPCI),
>>      .instance_init = virtio_iommu_pci_instance_init,
> 
>