Re: [Qemu-devel] [PATCH 13/13] qdev-properties: Add pci-devaddr property

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jun 04, 2012 at 10:52:21AM +0200, Jan Kiszka wrote:
> Add a property to receive a fully qualified PCI device address.
> 
> Will be used by KVM device assignment.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

I'd like to ponder this a bit more.  What bothers me is that this mixes
two things:
	- addressing of qemu devices
		Using full device addresses there is a legacy feature,
		users really should supply the parent bus and
		the bus local address.
	- addressing devices on the linux host for assignment
		It so happens that the syntax matches
		the legacy naming very closely,
		but conceptually is completely unrelated

> ---
>  hw/qdev-properties.c |   48 ++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/qdev.h            |    3 +++
>  2 files changed, 51 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
> index 32e41f1..6634f22 100644
> --- a/hw/qdev-properties.c
> +++ b/hw/qdev-properties.c
> @@ -946,6 +946,54 @@ PropertyInfo qdev_prop_pci_devfn = {
>      .max   = 0xFFFFFFFFULL,
>  };
>  
> +static void get_pci_devaddr(Object *obj, Visitor *v, void *opaque,
> +                            const char *name, Error **errp)
> +{
> +    DeviceState *dev = DEVICE(obj);
> +    Property *prop = opaque;
> +    PCIDeviceAddress *addr = qdev_get_prop_ptr(dev, prop);
> +    char buffer[10 + 3 + 1];
> +    char *p = buffer;
> +
> +    snprintf(buffer, sizeof(buffer), "%04x:%02x:%02x.%02x",
> +             addr->domain, addr->bus, addr->slot, addr->function);
> +
> +    visit_type_str(v, &p, name, errp);
> +}
> +
> +static void set_pci_devaddr(Object *obj, Visitor *v, void *opaque,
> +                            const char *name, Error **errp)
> +{
> +    DeviceState *dev = DEVICE(obj);
> +    Property *prop = opaque;
> +    PCIDeviceAddress *addr = qdev_get_prop_ptr(dev, prop);
> +    Error *local_err = NULL;
> +    char *str;
> +
> +    if (dev->state != DEV_STATE_CREATED) {
> +        error_set(errp, QERR_PERMISSION_DENIED);
> +        return;
> +    }
> +
> +    visit_type_str(v, &str, name, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    if (qemu_parse_pci_devaddr(str, addr,
> +                               PCI_DEVADDR_WITH_DOM_BUS_OPT |
> +                               PCI_DEVADDR_WITH_FUNC) < 0) {
> +        error_set_from_qdev_prop_error(errp, EINVAL, dev, prop, str);
> +    }
> +}
> +
> +PropertyInfo qdev_prop_pci_devaddr = {
> +    .name  = "pci-devaddr",

This is a very confusing name.  Something like host-pci-address?
This also should be built on linux only.
Can this be part of device assignment code instead of qdev?



> +    .get   = get_pci_devaddr,
> +    .set   = set_pci_devaddr,
> +};
> +
>  /* --- blocksize --- */
>  
>  static void set_blocksize(Object *obj, Visitor *v, void *opaque,
> diff --git a/hw/qdev.h b/hw/qdev.h
> index 15acfca..d2c87a0 100644
> --- a/hw/qdev.h
> +++ b/hw/qdev.h
> @@ -224,6 +224,7 @@ extern PropertyInfo qdev_prop_drive;
>  extern PropertyInfo qdev_prop_netdev;
>  extern PropertyInfo qdev_prop_vlan;
>  extern PropertyInfo qdev_prop_pci_devfn;
> +extern PropertyInfo qdev_prop_pci_devaddr;
>  extern PropertyInfo qdev_prop_blocksize;
>  
>  #define DEFINE_PROP(_name, _state, _field, _prop, _type) { \
> @@ -288,6 +289,8 @@ extern PropertyInfo qdev_prop_blocksize;
>                          LostTickPolicy)
>  #define DEFINE_PROP_BLOCKSIZE(_n, _s, _f, _d) \
>      DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_blocksize, uint16_t)
> +#define DEFINE_PROP_PCI_DEVADDR(_n, _s, _f) \
> +    DEFINE_PROP(_n, _s, _f, qdev_prop_pci_devaddr, PCIDeviceAddress)
>  
>  #define DEFINE_PROP_END_OF_LIST()               \
>      {}
> -- 
> 1.7.3.4