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

[miaoyubo <miaoyubo@huawei.com>]

> -----Original Message-----
> From: Michael S. Tsirkin [mailto:mst@redhat.com]
> Sent: Monday, May 4, 2020 10:03 PM
> To: miaoyubo <miaoyubo@huawei.com>
> Cc: peter.maydell@linaro.org; shannon.zhaosl@gmail.com;
> lersek@redhat.com; imammedo@redhat.com; qemu-devel@nongnu.org;
> berrange@redhat.com; Xiexiangyou <xiexiangyou@huawei.com>
> Subject: Re: [PATCH v6 2/8] fw_cfg: Write the extra roots into the fw_cfg
> 
> 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?
>

Thanks for your reply. I will add the API in patch v7.
 
> > @@ -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.
> 

Sure. It would be done in patch v7

> >  }
> > --
> > 2.19.1
> >

Regards,
Miao