Re: [PATCH v3 18/19] hw/arm: Do not build to 'virt' machine on Xen

[Philippe Mathieu-Daudé]

On 3/16/20 6:11 PM, Peter Maydell wrote:
> On Mon, 16 Mar 2020 at 16:08, Philippe Mathieu-Daudé <address@hidden> wrote:
> > Xen on ARM does not use QEMU machines [*]. Disable the 'virt'
> > machine there to avoid odd errors such:
> >
> >      CC      i386-softmmu/hw/cpu/a15mpcore.o
> >    hw/cpu/a15mpcore.c:28:10: fatal error: kvm_arm.h: No such file or directory
> >
> > [*] 
> > https://wiki.xenproject.org/wiki/Xen_ARM_with_Virtualization_Extensions#Use_of_qemu-system-i386_on_ARM
> >
> > Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> > ---
> > Cc: Stefano Stabellini <address@hidden>
> > Cc: Anthony Perard <address@hidden>
> > Cc: Paul Durrant <address@hidden>
> > Cc: address@hidden
> > ---
> >   hw/arm/Kconfig | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> > index 8e801cd15f..69a8e30125 100644
> > --- a/hw/arm/Kconfig
> > +++ b/hw/arm/Kconfig
> > @@ -1,5 +1,6 @@
> >   config ARM_VIRT
> >       bool
> > +    depends on !XEN
> >       default y if KVM
> >       imply PCI_DEVICES
> >       imply TEST_DEVICES
> > --
>
> This seems odd to me:
> (1) the error message you quote is for a15mpcore.c, not virt.c

This is the first device the virt board selects:

config ARM_VIRT
    bool
    imply PCI_DEVICES
    imply TEST_DEVICES
    imply VFIO_AMD_XGBE
    imply VFIO_PLATFORM
    imply VFIO_XGMAC
    imply TPM_TIS_SYSBUS
    select A15MPCORE
    ...

> (2) shouldn't this be prevented by something saying "don't build
> guest architecture X boards into Y-softmmu", rather than a specific
> flag for a specific arm board ?

Yes, agreed. This surgical change was quicker for my testing, but we 
don't need this patch right now, so let's drop it.

> thanks
> -- PMM