On Sat, Nov 20, 2021 at 03:20:45 -0500, huangy81@xxxxxxxxxxxxxxx wrote: > From: Hyman Huang(黄勇) <huangy81@xxxxxxxxxxxxxxx> > > since the "-machine" option for accelerators is legacy, "-accel" option > may be a better mechanism. following are details: > https://lore.kernel.org/qemu-devel/3aa73987-40e8-3619-0723-9f17f73850bd@xxxxxxxxxx/ > > this patch introduce QEMU_CAPS_ACCEL capability to tell if we're dealing > new enough QEMU so that we can replace '-machine accel' with '-accel'. > > there were two phases of -accel support in QEMU: > - 2.9 to 4.2: only one -accel option supported; specifying a fallback > couldn't be done with -accel and required the older "-machine accel=tcg:kvm" > instead. > > - 5.0 or newer: multiple -accel options supported, e.g. "-accel tcg > -accel kvm" > and it would be possible to distinguish them, for example using QOM > properties. > > however libvirt only ever specifies one accelerator so it makes no > difference. > > since the oldest supported qemu by libvirt is qemu-2.11, so modify > capability test cases with QEMU version >= 2.11.0 carefully. Well, this actually means we don't need the capability at all, we can just unconditionally switch to -accel. Michal attempted the same: https://listman.redhat.com/archives/libvir-list/2021-November/msg00196.html This patch should be dropped, the capability can be removed from any subsequent patches.
