Re: [Qemu-devel] [virtio-dev] Re: [PATCH v3] crypto: add virtio-crypto driver

[Gonglei (Arei)]

>
> Subject: [virtio-dev] Re: [PATCH v3] crypto: add virtio-crypto driver
> 
> On Mon, 28 Nov 2016 20:08:23 +0800
> Gonglei <address@hidden> wrote:
> 
> > +static int virtcrypto_update_status(struct virtio_crypto *vcrypto)
> > +{
> > +   u32 status;
> > +   int err;
> > +
> > +   virtio_cread(vcrypto->vdev,
> > +       struct virtio_crypto_config, status, &status);
> > +
> > +   /* Ignore unknown (future) status bits */
> > +   status &= VIRTIO_CRYPTO_S_HW_READY;
> 
> I'm wondering what the driver really should do if it encounters unknown
> status bits.
> 
> I'd expect that new status bits are guarded by a feature bit and that
> the device should not set status bits if the respective feature bit has
> not been negotiated. Therefore, unknown status bits would be a host
> error and the driver should consider the device to be broken.
> 
> Thoughts?
> 
I agree with you. 

The reasonable way is reset the device if the driver
receive an unknown status IMO.

Regards,
-Gonglei

> > +
> > +   if (vcrypto->status == status)
> > +           return 0;
> > +
> > +   vcrypto->status = status;
> > +
> > +   if (vcrypto->status & VIRTIO_CRYPTO_S_HW_READY) {
> > +           err = virtcrypto_dev_start(vcrypto);
> > +           if (err) {
> > +                   dev_err(&vcrypto->vdev->dev,
> > +                           "Failed to start virtio crypto device.\n");
> > +                   virtcrypto_dev_stop(vcrypto);
> > +                   return -EPERM;
> > +           }
> > +           dev_info(&vcrypto->vdev->dev, "Accelerator is ready\n");
> > +   } else {
> > +           virtcrypto_dev_stop(vcrypto);
> > +           dev_info(&vcrypto->vdev->dev, "Accelerator is not ready\n");
> > +   }
> > +
> > +   return 0;
> > +}
> > +
> 
> 
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