Hi Alyssa, On 6/17/25 4:17 PM, Alyssa Ross wrote: > Eric Auger <eric.au...@redhat.com> writes: > >> From: Haibo Xu <haibo...@linaro.org> >> >> Up to now virt support on guest has been only supported with TCG. >> Now it becomes feasible to use it with KVM acceleration. >> >> Also check only in-kernel GICv3 is used along with KVM EL2. >> >> Signed-off-by: Haibo Xu <haibo...@linaro.org> >> Signed-off-by: Miguel Luis <miguel.l...@oracle.com> >> Signed-off-by: Eric Auger <eric.au...@redhat.com> >> Reviewed-by: Richard Henderson <richard.hender...@linaro.org> > Hi! From what I can tell, this will produce an error on hosts that > don't support nested virtualization when QEMU is invoked with -accel > kvm:tcg -machine virtualization=on, but I don't think that's the ideal Thanks for reporting this issue. This is not an expected behavior. I will respin hopefully this week so I will have give it a try.
What kind of error msg do you get? Thanks Eric > behaviour. It would make more sense for it to fall back to the first > permitted accel option that does support running the machine as > configured, so if hardware nested virtualization is not supported, it > should fall back to TCG. > > I maintain an OS development environment that includes scripts for > running images in QEMU, where running KVM on those images is a > requirement. Currently, those scripts simply force TCG on aarch64. > With this change, to take advantage of KVM NV support, I'd have to try > to identify in the script whether NV would be supported. QEMU would be > in a much better position to determine this and fall back to TCG if it's > unsupported, like how the -accel option with multiple values usually > works.
