Re: [PATCH 16/17] pnv_phb4.c: do not set 'root-bus' as bus name

[Cédric Le Goater]

On 12/28/21 20:38, Daniel Henrique Barboza wrote:
> This change has the same motivation as the one done for pnv-phb3-root-bus
> buses previously. Defaulting every bus to 'root-bus' makes it impossible to 
> attach
> root ports to specific buses and it doesn't allow for custom bus
> naming because we're ignoring the 'id' value when registering the root
> bus.
>
> After this patch, creating pnv-phb4 devices with 'id' being set will
> result in the following qtree:
>
> qemu-system-ppc64 -m 4G -machine powernv9,accel=tcg \
>     -device pnv-phb4,chip-id=0,index=0,id=pcie.0 \
>     -device pnv-phb4,chip-id=1,index=4,id=pcie.1
>
> bus: main-system-bus
>    type System
>    dev: pnv-phb4, id "pcie.1"
>      index = 4 (0x4)
>      chip-id = 1 (0x1)
>      version = 704374636546 (0xa400000002)
>      device-id = 1217 (0x4c1)
>      x-config-reg-migration-enabled = true
>      bypass-iommu = false
>      bus: pcie.1
>        type pnv-phb4-root-bus
>    dev: pnv-phb4, id "pcie.0"
>      index = 0 (0x0)
>      chip-id = 0 (0x0)
>      version = 704374636546 (0xa400000002)
>      device-id = 1217 (0x4c1)
>      x-config-reg-migration-enabled = true
>      bypass-iommu = false
>      bus: pcie.0
>        type pnv-phb4-root-bus
>
> And without setting any ids:
>
> qemu-system-ppc64 -m 4G -machine powernv9,accel=tcg \
>     -device pnv-phb4,chip-id=0,index=0,id=pcie.0 \
>     -device pnv-phb4,chip-id=1,index=4,id=pcie.1
>
> bus: main-system-bus
>    type System
>    dev: pnv-phb4, id ""
>      index = 4 (0x4)
>      chip-id = 1 (0x1)
>      version = 704374636546 (0xa400000002)
>      device-id = 1217 (0x4c1)
>      x-config-reg-migration-enabled = true
>      bypass-iommu = false
>      bus: pnv-phb4-root-bus.1
>        type pnv-phb4-root-bus
>    dev: pnv-phb4, id ""
>      index = 0 (0x0)
>      chip-id = 0 (0x0)
>      version = 704374636546 (0xa400000002)
>      device-id = 1217 (0x4c1)
>      x-config-reg-migration-enabled = true
>      bypass-iommu = false
>      bus: pnv-phb4-root-bus.0
>        type pnv-phb4-root-bus
>
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.


> ---
>   hw/pci-host/pnv_phb4.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
> index 7b53c12b7c..982a61ebc0 100644
> --- a/hw/pci-host/pnv_phb4.c
> +++ b/hw/pci-host/pnv_phb4.c
> @@ -1354,7 +1354,7 @@ static void pnv_phb4_realize(DeviceState *dev, Error 
> **errp)
>       memory_region_init(&phb->pci_mmio, OBJECT(phb), name,
>                          PCI_MMIO_TOTAL_SIZE);
>   
> -    pci->bus = pci_register_root_bus(dev, "root-bus",
> +    pci->bus = pci_register_root_bus(dev, dev->id,
>                                        pnv_phb4_set_irq, pnv_phb4_map_irq, phb,
>                                        &phb->pci_mmio, &phb->pci_io,
>                                        0, 4, TYPE_PNV_PHB4_ROOT_BUS);