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

[Gonglei (Arei)]

Hi Michael,

Happy to listen to your voice :)


> -----Original Message-----
> From: Michael S. Tsirkin [mailto:address@hidden
> Sent: Monday, October 10, 2016 7:48 AM
> Subject: Re: [PATCH v5 11/14] virtio-crypto: emulate virtio crypto as a legacy
> device by default
> 
> 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 <address@hidden>
> 
> Sorry, I don't think this makes any sense.
> 
> You certainly can have two drivers: one for legacy and one for modern
> devices. 

Oh, This is indeed a solution.

> It only gets difficult if you try to support transitional
> devices.
> 
> Pls drop this patch.
> 
OK, then I have to temporarily drop the patch 12/14 as well because libqtest
doesn't support virtio-1.0 device yet. 


Regards,
-Gonglei

> > ---
> >  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
> >