On Thu, Jun 23 2022, Thomas Huth <th...@redhat.com> wrote:
> Feature negotiation should be done first, since some fields in the
> config area can depend on the negotiated features and thus should
> rather be read afterwards.
I suppose we don't negotiate any features that might affect the size of
the config space? Anyway, restricting ourselves to the minimum length
should be fine.
>
> Signed-off-by: Thomas Huth <th...@redhat.com>
> ---
> pc-bios/s390-ccw/virtio.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
> index 4e85a2eb82..0e92e994df 100644
> --- a/pc-bios/s390-ccw/virtio.c
> +++ b/pc-bios/s390-ccw/virtio.c
> @@ -262,10 +262,6 @@ void virtio_setup_ccw(VDev *vdev)
> rc = run_ccw(vdev, CCW_CMD_WRITE_STATUS, &status, sizeof(status), false);
> IPL_assert(rc == 0, "Could not write DRIVER status to host");
>
> - IPL_assert(
> - run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size, false) ==
> 0,
> - "Could not get block device configuration");
> -
> /* Feature negotiation */
> for (i = 0; i < ARRAY_SIZE(vdev->guest_features); i++) {
> feats.features = 0;
> @@ -278,6 +274,9 @@ void virtio_setup_ccw(VDev *vdev)
> IPL_assert(rc == 0, "Could not set features bits");
> }
>
> + rc = run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size, false);
> + IPL_assert(rc == 0, "Could not get block device configuration");
Since you move this anyway: s/block device/boot device/ ?
> +
> for (i = 0; i < vdev->nr_vqs; i++) {
> VqInfo info = {
> .queue = (unsigned long long) ring_area + (i * VIRTIO_RING_SIZE),
Related to feature negotiation: It seems that the bios currently
supports legacy virtio only, doesn't it? It's probably fine for now, but
there might be a way in the future to disable legacy virtio for all
devices in QEMU, so we'll probably want to add virtio-1 support some
day.
