Re: [PATCH v3 4/8] pc-bios/s390-ccw: Add support for virtio-net-pci IPL

[Joshua Daley <jdaley@linux.ibm.com>]

FYI, now that Jared's virtio-scsi-pci boot series is merged, this patch does not apply.

On 9/14/2026 3:34 PM, Zhuoying Cai wrote:
> Enable network booting via virtio-net-pci by implementing PCI transport
> support for virtio-net.
> 
> This patch also extends endianness handling for virtio PCI ring operations in
> little-endian to ensure correct behavior on s390x.
> 
> Signed-off-by: Zhuoying Cai <zycai@linux.ibm.com>
> Reviewed-by: Jared Rossi <jrossi@linux.ibm.com>
> ---
>   pc-bios/s390-ccw/main.c       |  1 +
>   pc-bios/s390-ccw/netmain.c    |  9 +++++++-
>   pc-bios/s390-ccw/virtio-net.c | 41 ++++++++++++++++++++++++++++-------
>   pc-bios/s390-ccw/virtio-pci.c | 20 +++++++++++++++++
>   4 files changed, 62 insertions(+), 9 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
> index 8fc1cbf653..28cab3b411 100644
> --- a/pc-bios/s390-ccw/main.c
> +++ b/pc-bios/s390-ccw/main.c
> @@ -332,6 +332,7 @@ static void ipl_pci_device(void)
>       }
>   
>       switch (vdev->dev_type) {
> +    case VIRTIO_ID_NET:
>       case VIRTIO_ID_BLOCK:
>           if (virtio_setup() == 0) {
>               zipl_load(); /* only return on error */
case VIRTIO_ID_SCSI has been added here

..snip...

> diff --git a/pc-bios/s390-ccw/virtio-pci.c b/pc-bios/s390-ccw/virtio-pci.c
> index f501252c81..fd794bad8f 100644
> --- a/pc-bios/s390-ccw/virtio-pci.c
> +++ b/pc-bios/s390-ccw/virtio-pci.c
> @@ -52,6 +52,10 @@ void virtio_pci_id2type(VDev *vdev, uint16_t device_id)
>       case 0x1001:
>           vdev->dev_type = VIRTIO_ID_BLOCK;
>           break;
> +    case 0x1041:
> +    case 0x1000:
> +        vdev->dev_type = VIRTIO_ID_NET;
> +        break;
>       default:
>           vdev->dev_type = 0;
>       }
some new cases were added here also

> @@ -199,6 +203,17 @@ static int virtio_pci_get_blk_config(void)
>       return rc;
>   }
>   
> +static int virtio_pci_get_net_config(void)
> +{
> +    VirtioNetConfig *cfg = &virtio_get_device()->config.net;
> +
> +    /*
> +     * Byte-swapping is not needed as only the MAC address (byte array)
> +     * is used here. Byte-swap if other fields are added.
> +     */
> +    return vpci_read_flex(d_cap.off, d_cap.bar, cfg, sizeof(VirtioNetConfig));
> +}
> +
>   static int virtio_pci_negotiate(void)
>   {
>       int i, rc;
> @@ -330,6 +345,7 @@ bool virtio_pci_is_supported(VDev *vdev)
>       if (vdev->vendor_id == PCI_VENDOR_VIRTIO) {
>           switch (vdev->dev_type) {
>           case VIRTIO_ID_BLOCK:
> +        case VIRTIO_ID_NET:
>               return true;
>           default:
>               return false;
here also

> @@ -384,6 +400,10 @@ int virtio_pci_setup(VDev *vdev)
>           vdev->cmd_vr_idx = 0;
>           virtio_pci_get_blk_config();
>           break;
> +    case VIRTIO_ID_NET:
> +        vdev->nr_vqs = 2;
> +        virtio_pci_get_net_config();
> +        break;
>       default:
>           puts("Unsupported virtio device");
>           return -ENODEV;
here also