Re: [Qemu-devel] [PATCH] arm: virt-acpi: each MADT.GICC entry as enabled unconditionally

[Andrew Jones]

On Fri, Jan 29, 2016 at 05:07:31PM +0100, Andrew Jones wrote:
> On Fri, Jan 29, 2016 at 11:44:24PM +0800, Shannon Zhao wrote:
> > >>>And below check in virt.c is not right while it should compare the global
> > >>>max_cpus with the max_cpus GIC supports.
> > >>>
> > >>>     if (smp_cpus > max_cpus) {
> > >>>         error_report("Number of SMP CPUs requested (%d) exceeds max 
> > >>> CPUs "
> > >>>                      "supported by machine 'mach-virt' (%d)",
> > >>>                      smp_cpus, max_cpus);
> > >>>         exit(1);
> > >>>     }
> > >max_cpus is getting set to the number the gic supports just above this
> > >check. So max_cpus == gic_supported_cpus already, and this check is just
> > >confirming the number of cpus the user has selected is OK.
> > No, the global max_cpus (which is defined in vl.c and exported in
> > sysemu/sysemu.h) is not the local variable max_cpus.
> 
> I now see what you mean though. If we don't want something like
> -smp 1,maxcpus=9 to erroneously succeed on a gicv2 machine, then we
> should be checking the global max_cpus here. I agree it should be
> fixed, because, even though it changes nothing atm, we don't want to
> allow invalid command lines.
> 
> Will you send the patch?

I'll send one in a second.

drew