Re: [Qemu-devel] [PATCH v4] hw/arm: Add arm SBSA reference machine

[Hongbo Zhang]

On Wed, 5 Dec 2018 at 18:36, Leif Lindholm <address@hidden> wrote:
>
> On Wed, Dec 05, 2018 at 05:50:23PM +0800, Hongbo Zhang wrote:
> > > > +static
> > > > +void sbsa_ref_machine_done(Notifier *notifier, void *data)
> > > > +{
> > > > +    VirtMachineState *vms = container_of(notifier, VirtMachineState,
> > > > +                                         machine_done);
> > > > +    ARMCPU *cpu = ARM_CPU(first_cpu);
> > > > +    struct arm_boot_info *info = &vms->bootinfo;
> > > > +    AddressSpace *as = arm_boot_address_space(cpu, info);
> > > > +
> > > > +    if (arm_load_dtb(info->dtb_start, info, info->dtb_limit, as) < 0) {
> > > > +        exit(1);
> > > > +    }
> > > > +}
> > >
> > > The virt board needs a machine-done notifier because it has
> > > to add extra things to the DTB here. You don't, so you don't
> > > need one. Don't set bootinfo.skip_dtb_autoload to true, and
> > > then the boot.c code will do the arm_load_dtb() call for you.
> > >
> > After test and check, I think we still need this machine_done callback
> > to call arm_load_dtb().
> > If only kernel loaded via -kernel but without any firmware, it should
> > work to let arm_load_kernel() call the arm_load_dtb(), while in our
> > case, we have have firmware loaded but no kernel, so the
> > arm_load_kernel() returns before calling arm_load_dtb(),  that is,
> > firmware runs and there is no chance to call arm_load_dtb(), then we
> > get error message and qemu quits.
> > Moving arm_load_dtb() to earlier place in arm_load_kernel() cannot fix
> > this issue either.
>
> I don't see the value in using -kernel on the SBSA machine.
> If it causes complexity, can we drop the functionality?
>
We don't use -kernel parameter on SBSA machine.
It doesn't cause complexity,  we were suggested to drop the previous
machine_done() callback to reduce code lines, but I think we have to
use it still.

> Regards,
>
> Leif