Re: [Qemu-devel] [PATCH] spapr-pci: change the default PCI bus naming

[Paolo Bonzini <pbonzini@redhat.com>]

Il 06/03/2014 04:11, Alexey Kardashevskiy ha scritto:
> Previously libvirt required the first/default PCI bus to have name "pci".
> Since QEMU can support multiple buses now, libvirt wants "pci.0" now.
>
> This removes custom busname and lets QEMU make up default names.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>
> I tested this with:
>   -netdev tap,id=id0,ifname=tapqemu-tap-00,script=ifup.sh,downscript=ifdown.sh \
>   -device e1000,id=id1,netdev=id0,mac=C0:41:49:4b:00:00 \
>   -device \
>   spapr-pci-host-bridge,index=5,id=aikbus \
>   -netdev tap,id=id2,ifname=tap-1,script=ifup.sh,downscript=ifdown.sh \
>   -device rtl8139,id=id3,netdev=id2,bus=aikbus.0,mac=C0:41:49:4b:00:01 \
>   -device spapr-pci-vfio-host-bridge,id=id4,index=10,iommu=4 \
>
> This creates a default PCI, an additional emulated PCI bus (named aikbus,
> if I omit the name, it is pci.1 which is also fine) and VFIO bus (which is
> not in upstream yet but still), this all works fine and I cannot see any flaw.

Thanks!

Andreas, are you taking this patch?

Paolo

>
> ---
>  hw/ppc/spapr_pci.c | 23 ++---------------------
>  1 file changed, 2 insertions(+), 21 deletions(-)
>
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 66ddf10..7ecb3df 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -499,7 +499,6 @@ static int spapr_phb_init(SysBusDevice *s)
>      DeviceState *dev = DEVICE(s);
>      sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
>      PCIHostState *phb = PCI_HOST_BRIDGE(s);
> -    const char *busname;
>      char *namebuf;
>      int i;
>      PCIBus *bus;
> @@ -583,26 +582,8 @@ static int spapr_phb_init(SysBusDevice *s)
>                               get_system_io(), 0, SPAPR_PCI_IO_WIN_SIZE);
>      memory_region_add_subregion(get_system_memory(), sphb->io_win_addr,
>                                  &sphb->iowindow);
> -    /*
> -     * Selecting a busname is more complex than you'd think, due to
> -     * interacting constraints.  If the user has specified an id
> -     * explicitly for the phb , then we want to use the qdev default
> -     * of naming the bus based on the bridge device (so the user can
> -     * then assign devices to it in the way they expect).  For the
> -     * first / default PCI bus (index=0) we want to use just "pci"
> -     * because libvirt expects there to be a bus called, simply,
> -     * "pci".  Otherwise, we use the same name as in the device tree,
> -     * since it's unique by construction, and makes the guest visible
> -     * BUID clear.
> -     */
> -    if (dev->id) {
> -        busname = NULL;
> -    } else if (sphb->index == 0) {
> -        busname = "pci";
> -    } else {
> -        busname = sphb->dtbusname;
> -    }
> -    bus = pci_register_bus(dev, busname,
> +
> +    bus = pci_register_bus(dev, NULL,
>                             pci_spapr_set_irq, pci_spapr_map_irq, sphb,
>                             &sphb->memspace, &sphb->iospace,
>                             PCI_DEVFN(0, 0), PCI_NUM_PINS, TYPE_PCI_BUS);
>