On Mon, Oct 21, 2019 at 02:23:15PM +0200, Thomas Huth wrote:
> On 19/10/2019 08.38, Stefan Hajnoczi wrote:
> > Device initialization has an extra step in VIRTIO 1.0. The FEATURES_OK
> > status bit is set to indicate that feature negotiation has completed.
> > The driver then reads the status register again to check that the device
> > agrees with the final features.
> >
> > Implement this step as part of qvirtio_set_features() instead of
> > introducing a separate function. This way all existing code works
> > without modifications.
> >
> > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
> > ---
> > tests/libqos/virtio.c | 20 +++++++++++++++++---
> > 1 file changed, 17 insertions(+), 3 deletions(-)
> [...]
> > @@ -88,9 +101,10 @@ void qvirtio_set_driver(QVirtioDevice *d)
> >
> > void qvirtio_set_driver_ok(QVirtioDevice *d)
> > {
> > - d->bus->set_status(d, d->bus->get_status(d) |
> > VIRTIO_CONFIG_S_DRIVER_OK);
> > - g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_DRIVER_OK |
> > - VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE);
> > + uint8_t status = d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER_OK;
> > +
> > + d->bus->set_status(d, status);
> > + g_assert_cmphex(d->bus->get_status(d), ==, status);
> > }
>
> The changes to qvirtio_set_driver_ok() are not mentioned in the patch
> description. Please either mention them there, or move this to a
> separate patch.Will fix in v4. We can no longer hardcode the status register value for DRIVER_OK since it now depends on whether VIRTIO 1.0 is used or not. Here is an alternative that is smaller and makes the VIRTIO 1.0 dependency obvious: - g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_DRIVER_OK | - VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE); + g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_DRIVER_OK | + VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE | + (d->features & (1ull << VIRTIO_F_VERSION_1) ? + VIRTIO_CONFIG_S_FEATURES_OK : 0)); Stefan
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