On Tue, Feb 02, 2016 at 01:15:49PM +0000, Peter Maydell wrote:
On 2 February 2016 at 12:59, Andrew Jones <drjones@redhat.com> wrote:
This actually doesn't matter for the v2 vs. v3 case. The gic-version property doesn't exist at all for v2-only QEMU. Although maybe the gic-version property should be reworked. Instead of gic-version=<highest-supported>, we could create one boolean property per version supported, i.e. gicv2, gicv3, gicv4...
QEMU 2.5 released with the gic-version property, so we can't just drop it now; that would break users' command lines. We'd need a strong argument for why it's worth adding new properties that duplicate the legacy syntax.
I agree we should have a good argument to justify messing with it, but until we start versioning mach-virt, then I don't think anybody should depend on mach-virt command lines working everywhere. Every time we add a new property, and a user adds it to their command line, then they've just broken that command line for older QEMU. Yes, I know the upgrade path is a bit different, but still... Anyway, properties are changeable with versioned machines. drew