On Sun, 7 Jun 2020 at 13:03, Heinrich Schuchardt <xypron.g...@gmx.de> wrote: > > Am June 7, 2020 8:59:00 AM UTC schrieb Ard Biesheuvel <a...@kernel.org>: > >On Sat, 6 Jun 2020 at 22:49, Heinrich Schuchardt <xypron.g...@gmx.de> > >wrote: > >> > >> On 6/6/20 10:32 PM, Heinrich Schuchardt wrote: > >> > On 6/6/20 7:15 PM, Ard Biesheuvel wrote: > >> >> QEMU's mach-virt machine only supports selecting CPU models that > >> >> implement the virtualization extensions, and are therefore > >guaranteed > >> >> to support LPAE as well. > >> > > >> > I wonder why > >> > qemu-system-arm -machine virt -cpu help > >> > lists cortex-a9 (which is not LPAE enabled). > >> > > >> > But when I try to use it I get > >> > qemu-system-arm: mach-virt: CPU type cortex-a9-arm-cpu not > >supported > >> > This looks like a missing feature in QEMU. > >> > > > > >This is not a missing feature. The virt board uses PSCI for powerdown > >and reset, and to bring up secondary cores. > >PSCI requires the HVC instruction, which is only available if the virt > >extensions are implemented. > > By missing feature I meant -cpu help output should be filtered according to > the -machine value if provided. >
Ah fair enough. Yes, that would be useful. Unfortunately, ARM does not permit me to contribute to QEMU, so hopefully someone else can take this on.