Re: [Qemu-devel] [PATCH v5 11/14] virtio-crypto: emulate virtio crypto as a legacy device by default

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Oct 06, 2016 at 07:36:44PM +0800, Gonglei wrote:
> the scenario of virtio crypto device is mostly NFV, which require
> the existing Guest can't need to do any changes to support virtio
> crypto, so that they can easily migrate the existing network units
> to VM. That's also a basic requirement came from our customers
> in production environment.
> 
> For virtio crypto driver, we can both support virtio-1.0 or earlier. But
> Virtio pci driver module can't discovery the virtio-1.0 devices in most
> existing Guests. If we want do this, we have to require the customers
> change the virtio pci module for existing guests influence all virtio
> devices, which is impossible.
>
> So, let's emulate the virtio crypto device as a legacy virtio
> device by default. Using 0x1014 as virtio crypto pci device ID
> because virtio crypto ID is 20 (0x14).
> 
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>

Sorry, I don't think this makes any sense.

You certainly can have two drivers: one for legacy and one for modern
devices.  It only gets difficult if you try to support transitional
devices.

Pls drop this patch.

> ---
>  docs/specs/pci-ids.txt        | 2 ++
>  hw/virtio/virtio-crypto-pci.c | 4 +++-
>  include/hw/pci/pci.h          | 2 ++
>  3 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/docs/specs/pci-ids.txt b/docs/specs/pci-ids.txt
> index fd27c67..662d4f8 100644
> --- a/docs/specs/pci-ids.txt
> +++ b/docs/specs/pci-ids.txt
> @@ -22,6 +22,7 @@ maintained as part of the virtio specification.
>  1af4:1004  SCSI host bus adapter device (legacy)
>  1af4:1005  entropy generator device (legacy)
>  1af4:1009  9p filesystem device (legacy)
> +1af4:1014  crypto device (legacy)
>  
>  1af4:1041  network device (modern)
>  1af4:1042  block device (modern)
> @@ -32,6 +33,7 @@ maintained as part of the virtio specification.
>  1af4:1049  9p filesystem device (modern)
>  1af4:1050  virtio gpu device (modern)
>  1af4:1052  virtio input device (modern)
> +1af4:1054  crypto device (modern)
>  
>  1af4:10f0  Available for experimental usage without registration.  Must get
>     to      official ID when the code leaves the test lab (i.e. when seeking
> diff --git a/hw/virtio/virtio-crypto-pci.c b/hw/virtio/virtio-crypto-pci.c
> index 21d9984..30c10f0 100644
> --- a/hw/virtio/virtio-crypto-pci.c
> +++ b/hw/virtio/virtio-crypto-pci.c
> @@ -32,7 +32,6 @@ static void virtio_crypto_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
>      DeviceState *vdev = DEVICE(&vcrypto->vdev);
>  
>      qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
> -    virtio_pci_force_virtio_1(vpci_dev);
>      object_property_set_bool(OBJECT(vdev), true, "realized", errp);
>      object_property_set_link(OBJECT(vcrypto),
>                   OBJECT(vcrypto->vdev.conf.cryptodev), "cryptodev",
> @@ -49,6 +48,9 @@ static void virtio_crypto_pci_class_init(ObjectClass *klass, void *data)
>      set_bit(DEVICE_CATEGORY_MISC, dc->categories);
>      dc->props = virtio_crypto_pci_properties;
>  
> +    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
> +    pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_CRYPTO;
> +    pcidev_k->revision = 0;
>      pcidev_k->class_id = PCI_CLASS_OTHERS;
>  }
>  
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 772692f..5881101 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -83,6 +83,8 @@
>  #define PCI_DEVICE_ID_VIRTIO_RNG         0x1005
>  #define PCI_DEVICE_ID_VIRTIO_9P          0x1009
>  #define PCI_DEVICE_ID_VIRTIO_VSOCK       0x1012
> +#define PCI_DEVICE_ID_VIRTIO_CRYPTO      0x1014
> +
>  
>  #define PCI_VENDOR_ID_REDHAT             0x1b36
>  #define PCI_DEVICE_ID_REDHAT_BRIDGE      0x0001
> -- 
> 1.7.12.4
>