Re: [PATCH] piix: use pci_config_set_prog_interface()

Michael S. Tsirkin wrote:
> On Mon, Dec 20, 2010 at 10:18:01PM +0100, Sebastian Herbszt wrote:
>> Use pci_config_set_prog_interface().
>> 
>> Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
> 
> Since I was asked explicitly - I don't have a problem
> with these changes: both class and prog interface.
> However, they aren't all that useful in themselves.
> 
> For class, what I would like to see is a system where
> the device class is put in the qdev info table,
> and where -device ?
> (and hopefully the legacy -help, -nic etc as well)
> use this information.

I am not sure if you mean something like the patch below.

> pci_config_set_prog_interface can then have an assert to
> verify that value.
> Maybe we can even make e.g. -device nic work.
> 
> In a similar way, pci_config_set_prog_interface
> would really become useful if we put the handling
> for the legacy classes in a central place
> (e.g. pci_class.c)

Which are "legacy classes"?

> Any chance of doing something like the above?
> I'd be happy to apply such patches.

Sebastian

On Tue, Dec 28, 2010 at 05:24:06PM +0100, Sebastian Herbszt wrote:
> Michael S. Tsirkin wrote:
> >On Mon, Dec 20, 2010 at 10:18:01PM +0100, Sebastian Herbszt wrote:
> >>Use pci_config_set_prog_interface().
> >>
> >>Signed-off-by: Sebastian Herbszt <herbszt@gmx.de>
> >
> >Since I was asked explicitly - I don't have a problem
> >with these changes: both class and prog interface.
> >However, they aren't all that useful in themselves.
> >
> >For class, what I would like to see is a system where
> >the device class is put in the qdev info table,
> >and where -device ?
> >(and hopefully the legacy -help, -nic etc as well)
> >use this information.
> 
> I am not sure if you mean something like the patch below.

Not exactly

- I'd like to keep the pci_config_set_class in the devices,
  just make it do an assert.
- Nics already have DEFINE_NIC_PROPERTIES - can this be used somehow?
  Same for other devices ...
- This is still just moving bits around.
  The main point would be to report device type in -device ?
  and friends.

> >pci_config_set_prog_interface can then have an assert to
> >verify that value.
> >Maybe we can even make e.g. -device nic work.
> >
> >In a similar way, pci_config_set_prog_interface
> >would really become useful if we put the handling
> >for the legacy classes in a central place
> >(e.g. pci_class.c)
> 
> Which are "legacy classes"?

Some class/programming interface combinations let
devices claim IO addresses not requested using a BAR.
This is currently hard-coded in each such device.

> >Any chance of doing something like the above?
> >I'd be happy to apply such patches.
> 
> Sebastian
> 
> diff --git a/hw/e1000.c b/hw/e1000.c
> index af101bd..88ace8f 100644
> --- a/hw/e1000.c
> +++ b/hw/e1000.c
> @@ -1117,7 +1117,6 @@ static int pci_e1000_init(PCIDevice *pci_dev)
>     /* TODO: we have no capabilities, so why is this bit set? */
>     pci_set_word(pci_conf + PCI_STATUS, PCI_STATUS_CAP_LIST);
>     pci_conf[PCI_REVISION_ID] = 0x03;
> -    pci_config_set_class(pci_conf, PCI_CLASS_NETWORK_ETHERNET);
>     /* TODO: RST# value should be 0, PCI spec 6.2.4 */
>     pci_conf[PCI_CACHE_LINE_SIZE] = 0x10;
> 
> @@ -1169,6 +1168,7 @@ static PCIDeviceInfo e1000_info = {
>     .init       = pci_e1000_init,
>     .exit       = pci_e1000_uninit,
>     .romfile    = "pxe-e1000.bin",
> +    .class      = PCI_CLASS_NETWORK_ETHERNET,
>     .qdev.props = (Property[]) {
>         DEFINE_NIC_PROPERTIES(E1000State, conf),
>         DEFINE_PROP_END_OF_LIST(),
> diff --git a/hw/pci.c b/hw/pci.c
> index ef00d20..de0038c 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -1620,6 +1620,11 @@ static int pci_qdev_init(DeviceState *qdev, DeviceInfo *base)
>                                      info->is_bridge);
>     if (pci_dev == NULL)
>         return -1;
> +
> +    if (info->class) {
> +        pci_config_set_class(pci_dev->config, info->class);
> +    }
> +
>     rc = info->init(pci_dev);
>     if (rc != 0) {
>         do_pci_unregister_device(pci_dev);
> diff --git a/hw/pci.h b/hw/pci.h
> index 17744dc..29b9280 100644
> --- a/hw/pci.h
> +++ b/hw/pci.h
> @@ -436,6 +436,9 @@ typedef struct {
> 
>     /* rom bar */
>     const char *romfile;
> +
> +    /* class */
> +    uint16_t class;
> } PCIDeviceInfo;
> 
> void pci_qdev_register(PCIDeviceInfo *info);