Re: [Qemu-devel] [PATCH V2] hw/pxb: add chassis_nr property

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

On Mon, Oct 12, 2015 at 01:09:37PM +0300, Marcel Apfelbaum wrote:
> Add a chassis_nr property instead of using PXB bus number
> as internal bridge's chassis nr.
> 
> Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>

OK, but we need to be compatible with old systems.
So you need to use bus nr if chassis nr is 0.

> ---
> v1->v2:
>  - Rebased on master
> 
>  docs/pci_expander_bridge.txt        | 7 +++----
>  hw/pci-bridge/pci_expander_bridge.c | 5 ++++-
>  2 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/docs/pci_expander_bridge.txt b/docs/pci_expander_bridge.txt
> index d7913fb..fed2bbe 100644
> --- a/docs/pci_expander_bridge.txt
> +++ b/docs/pci_expander_bridge.txt
> @@ -23,9 +23,9 @@ A detailed command line would be:
>  -m 2G
>  -object memory-backend-ram,size=1024M,policy=bind,host-nodes=0,id=ram-node0 -numa node,nodeid=0,cpus=0,memdev=ram-node0
>  -object memory-backend-ram,size=1024M,policy=bind,host-nodes=1,id=ram-node1 -numa node,nodeid=1,cpus=1,memdev=ram-node1
> --device pxb,id=bridge1,bus=pci.0,numa_node=1,bus_nr=4 -netdev user,id=nd-device e1000,bus=bridge1,addr=0x4,netdev=nd
> --device pxb,id=bridge2,bus=pci.0,numa_node=0,bus_nr=8,bus=pci.0 -device e1000,bus=bridge2,addr=0x3
> --device pxb,id=bridge3,bus=pci.0,bus_nr=40,bus=pci.0 -drive if=none,id=drive0,file=[img] -device virtio-blk-pci,drive=drive0,scsi=off,bus=bridge3,addr=1
> +-device pxb,id=bridge1,bus=pci.0,numa_node=1,bus_nr=4,chassis_nr=1 -netdev user,id=nd-device e1000,bus=bridge1,addr=0x4,netdev=nd
> +-device pxb,id=bridge2,bus=pci.0,numa_node=0,bus_nr=8,bus=pci.0,chassis_nr=2 -device e1000,bus=bridge2,addr=0x3
> +-device pxb,id=bridge3,bus=pci.0,bus_nr=40,bus=pci.0,chassis_nr=3 -drive if=none,id=drive0,file=[img] -device virtio-blk-pci,drive=drive0,scsi=off,bus=bridge3,addr=1
>  
>  Here you have:
>   - 2 NUMA nodes for the guest, 0 and 1. (both mapped to the same NUMA node in host, but you can and should put it in different host NUMA nodes)
> @@ -55,4 +55,3 @@ The PXB is composed by:
>    - Using the bridge will enable hotplug support
>    - All the devices behind the bridge will use bridge's IO/MEM windows compacting
>      the PCI address space.
> -
> diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
> index 57f8a37..8645650 100644
> --- a/hw/pci-bridge/pci_expander_bridge.c
> +++ b/hw/pci-bridge/pci_expander_bridge.c
> @@ -39,6 +39,7 @@ typedef struct PXBDev {
>      PCIDevice parent_obj;
>      /*< public >*/
>  
> +    uint8_t chassis_nr;
>      uint8_t bus_nr;
>      uint16_t numa_node;
>  } PXBDev;
> @@ -220,7 +221,7 @@ static int pxb_dev_initfn(PCIDevice *dev)
>  
>      bds = qdev_create(BUS(bus), "pci-bridge");
>      bds->id = dev_name;
> -    qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
> +    qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->chassis_nr);
>      qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
>  
>      PCI_HOST_BRIDGE(ds)->bus = bus;
> @@ -248,6 +249,8 @@ static void pxb_dev_exitfn(PCIDevice *pci_dev)
>  }
>  
>  static Property pxb_dev_properties[] = {
> +    /* Note: 0 is not a legal chassis number. */
> +    DEFINE_PROP_UINT8("chassis_nr", PXBDev, chassis_nr, 0),
>      /* Note: 0 is not a legal a PXB bus number. */
>      DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
>      DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
> -- 
> 2.1.0