Re: [Qemu-devel] [PATCH 04/61] virtio-pci : refactor virtio-pci device.

[Peter Maydell]

On 7 January 2013 18:40,  <address@hidden> wrote:
> From: KONRAD Frederic <address@hidden>
>
> Create the virtio-pci device. This transport device will create a
> virtio-pci-bus, so one VirtIODevice can be connected.
>
> Signed-off-by: KONRAD Frederic <address@hidden>
> ---
>  hw/virtio-pci.c | 127 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/virtio-pci.h |  18 ++++++++
>  2 files changed, 145 insertions(+)
>
> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> index 5ff03e8..1f0ecbe 100644
> --- a/hw/virtio-pci.c
> +++ b/hw/virtio-pci.c
> @@ -1163,6 +1163,130 @@ static TypeInfo virtio_scsi_info = {
>      .class_init    = virtio_scsi_class_init,
>  };
>
> +/*
> + * virtio-pci : This is the PCIDevice which have a virtio-pci-bus.

"has"

> + */
> +
> +/* This is called by virtio-bus just after the device is plugged. */
> +static void virtio_pci_device_plugged(DeviceState *d)
> +{
> +    VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
> +    VirtioBusState *bus = proxy->bus;
> +    uint8_t *config;
> +    uint32_t size;
> +
> +    /* Put the PCI IDs */
> +    switch (virtio_device_get_id(proxy->bus)) {
> +
> +
> +    default:
> +        error_report("unknown device id\n");
> +        break;
> +
> +    }

This doesn't have any code in it yet (it gets added in later patches) but
the final result looks very repetitive. I think you'd be better off just having
some arrays:

uint16_t virtio_pci_device_id[] = {
     [VIRTIO_ID_BLOCK] = PCI_DEVICE_ID_VIRTIO_BLOCK,
     [VIRTIO_ID_NET] = PCI_DEVICE_ID_VIRTIO_NET,
(etc)
};

similarly for the class. Then you can just drop the switch statement.

In fact I think you might as well put in the array entries for all
the virtio devices in this patch rather than adding one in each of the
"add virtio-foo device" patches; it will do no harm for them to be
there early and it makes the later patches a little smaller.


> +
> +    proxy->vdev = proxy->bus->vdev;
> +
> +    config = proxy->pci_dev.config;
> +    if (proxy->class_code) {
> +        pci_config_set_class(config, proxy->class_code);
> +    }
> +    pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID,
> +                 pci_get_word(config + PCI_VENDOR_ID));
> +    pci_set_word(config + PCI_SUBSYSTEM_ID, 
> virtio_device_get_id(proxy->bus));
> +    config[PCI_INTERRUPT_PIN] = 1;

> --- a/hw/virtio-pci.h
> +++ b/hw/virtio-pci.h
> @@ -45,6 +45,22 @@ typedef struct {
>      unsigned int users;
>  } VirtIOIRQFD;
>
> +/*
> + * virtio-pci : This is the PCIDevice which have a virtio-pci-bus.

"has"

> + */

-- PMM