Re: [Qemu-devel] [kvm-unit-tests PATCH v5 09/11] arm: query /dev/kvm for maximum vcpus

From: Andrew Jones <drjones@redhat.com>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: mttcg@greensocs.com, mark.burton@greensocs.com,
	fred.konrad@greensocs.com, peter.maydell@linaro.org,
	"Alex Bennée" <alex@bennee.com>,
	kvm@vger.kernel.org, a.spyridakis@virtualopensystems.com,
	claudio.fontana@huawei.com, a.rigo@virtualopensystems.com,
	qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [kvm-unit-tests PATCH v5 09/11] arm: query /dev/kvm for maximum vcpus
Date: Sun, 2 Aug 2015 18:40:16 +0200	[thread overview]
Message-ID: <20150802164016.GC3441@hawk.localdomain> (raw)
In-Reply-To: <20150731191712.GI3680@hawk.localdomain>

On Fri, Jul 31, 2015 at 09:17:12PM +0200, Andrew Jones wrote:
> On Fri, Jul 31, 2015 at 04:53:59PM +0100, Alex Bennée wrote:
> > From: Alex Bennée <alex@bennee.com>
> > 
> > The previous $(getconf _NPROCESSORS_CONF) isn't correct as the default
> > maximum VCPU configuration is 4 on arm64 machines which typically have
> > more actual cores.
> 
> The kernel should probably bump that up to 8, but that's an aside,
> as it wouldn't resolve the general issue.
> 
> For this patch, I don't think we need a C utility as we can probe
> with QEMU, and thus just need a script.
> 
>   $QEMU -machine virt,accel=kvm -smp 9
>   Number of SMP cpus requested (9), exceeds max cpus supported by machine `virt' (8)
> 
> The script can live in $root/scripts/, which is a directory recently
> created for standalone test support.

I decided to take a stab at this and came up with

https://github.com/rhdrjones/kvm-unit-tests/commit/336d87338da86a0e7f2018a1e509b606b9a2baa2

Thanks,
drew