Re: [PATCH v6 2/8] fw_cfg: Write the extra roots into the fw_cfg

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

On Wed, Apr 08, 2020 at 08:58:10PM +0800, Yubo Miao wrote:
> From: miaoyubo <miaoyubo@huawei.com>
> 
> Write the extra roots into the fw_cfg therefore the uefi could
> get the extra roots. Only if the uefi know there are extra roots,
> the config space of devices behind the root could be obtained.
> 
> Signed-off-by: miaoyubo <miaoyubo@huawei.com>
> ---
>  hw/arm/virt.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 7dc96abf72..0fdfe4129c 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -77,6 +77,7 @@
>  #include "hw/acpi/generic_event_device.h"
>  #include "hw/virtio/virtio-iommu.h"
>  #include "hw/char/pl011.h"
> +#include "hw/pci/pci_bus.h"
>  
>  #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
>      static void virt_##major##_##minor##_class_init(ObjectClass *oc, \
> @@ -1435,6 +1436,12 @@ void virt_machine_done(Notifier *notifier, void *data)
>      ARMCPU *cpu = ARM_CPU(first_cpu);
>      struct arm_boot_info *info = &vms->bootinfo;
>      AddressSpace *as = arm_boot_address_space(cpu, info);
> +    PCIHostState *s = OBJECT_CHECK(PCIHostState,
> +                                   object_resolve_path_type("",
> +                                   "pcie-host-bridge", NULL),
> +                                   TYPE_PCI_HOST_BRIDGE);
> +
> +    PCIBus *bus = s->bus;
>  
>      /*
>       * If the user provided a dtb, we assume the dynamic sysbus nodes


Seems duplicated all over the place. Add an API for that?

> @@ -1453,6 +1460,22 @@ void virt_machine_done(Notifier *notifier, void *data)
>          exit(1);
>      }
>  
> +    if (bus) {
> +        int extra_hosts = 0;
> +        QLIST_FOREACH(bus, &bus->child, sibling) {
> +            /* look for expander root buses */
> +            if (pci_bus_is_root(bus)) {
> +                extra_hosts++;
> +            }
> +        }
> +        if (extra_hosts && vms->fw_cfg) {
> +            uint64_t *val = g_malloc(sizeof(*val));
> +            *val = cpu_to_le64(extra_hosts);
> +            fw_cfg_add_file(vms->fw_cfg,
> +                   "etc/extra-pci-roots", val, sizeof(*val));
> +        }
> +    }
> +
>      virt_acpi_setup(vms);
>      virt_build_smbios(vms);


Duplicated from pc. Pls refactor.

>  }
> -- 
> 2.19.1
>