On 3/4/21 6:19 PM, Claudio Fontana wrote: > On 3/4/21 5:39 PM, Philippe Mathieu-Daudé wrote: >> On 3/3/21 7:54 PM, Richard Henderson wrote: >>> On 3/3/21 10:45 AM, Claudio Fontana wrote: >>>> It is a bit weird that qemu-system-aarch64 runs with a cortex-a15 >>>> model tbh, as cortex-a15 is not capable of aarch64. >>> >>> No, but qemu-system-aarch64 is capable of 32-bit emulation (because most >>> 64-bit cpus retain 32-bit mode). It takes no extra effort to run >>> cortex-a15 than it does a cortex-a57. >> >> IIRC qemu-system-arm starts the aa64 cores in 32-bit mode, while >> qemu-system-aarch64 in 64-bit (this gave me trouble because the >> kernels for the raspi 64-bit SoCs are in 32-bit mode -- because >> the GPU starts them in this mode). >> >>> I have wondered if we should have just one qemu-system-arm that does it >>> all and drop the separate qemu-system-aarch64 -- or vice versa. But >>> we've had the separation around so long I'm sure someone would be confused. >> >> That would be great cleanup IMHO. >> > > Would we still be able to configure a lean AARCH64-only qemu that only > contains the cpu models we want, > (via board configuration / KConfig?),
We shouldn't even worry about this IMO. Because ... > for example, a kvm-only build that only has a few 64-bit cpu models in it, > plus max/host and removes all the rest? ... since host word-size becomes irrelevant, you only have to consider the accelerator possibilities. Restricting to KVM directly select a subset of CPUs usable.
