Improvement suggestion, an option for manual fallback to TCG

[CryptoManiac]

Hi. It would seem that Lima provides user with no other option but to use the hardware virtualization in some cases, despite technically being able to function without it.

lima/pkg/driver/qemu/qemu.go

Line 1110 in b9e8140

func Accel(arch limatype.Arch) string {

I believe it would be prudent to let the user alter the detection behavior here. This would make it possible to use Lima on those platforms which have no hardware virtualization. Like Ryzen hackintoshes or the virtual machines with no VMX instructions exposed to the guest.

I made a quick test by substitute the real qemu with a simple wrapper and everything works smoothly.

qemu_wrap.cc.txt

Or is there another way to this in a less invasive manner?

P.S. Note for those who might try this. Lima is using the qemu directory as a starting path to search for firmware files. Better to have the wrapper in the same directory with the qemu binary.

[AkihiroSuda]

I think automatically falling back to TCG is fine, as long as a clear warning is shown

[afbjorklund]

I think the shell wrapper was the preferred approach?

• Make it possible to set the accelerator for qemu #3173

[CryptoManiac]

@afbjorklund I can see that the said discussion implies the debugging while in fact it is anything but. There's a plenty of use cases when the hardware virtualization is unavailable. Like, for instance, running in a guest system. A plenty of hypervisors (e.g. Apple's own hypervisor framework) are not allowing the nested virtualization, making it impossible to use Lima without wrappers, patches or whatever other invasive solutions.

[afbjorklund]

Yeah well, I thought adding an accelType was reasonable.

• Ability to run aarch64 guests on Linux without KVM #3156