On Mon, 1 Feb 2021 at 08:18, Luc Michel <l...@lmichel.fr> wrote: > On 16:14 Sun 31 Jan , Philippe Mathieu-Daudé wrote: > > KVM requires the target cpu to be at least ARMv8 architecture > > (support on ARMv7 has been dropped in commit 82bf7ae84ce: > > "target/arm: Remove KVM support for 32-bit Arm hosts"). > Wow, is there absolutely no way to do that then? What about using an > ARMv8 and starting in AArch32 mode? Is that possible with KVM? I guess > it might not be strictly identical as spawning the "real" CPU...
"Support hardware-accelerated emulation of older v7 CPUs" is not a design goal of the virtualization extensions; you can't do it. KVM does support having a guest CPU which is AArch32 for EL1, but that will never be a v7 CPU, because it will be the same as the host CPU, which will always be v8. In general I would prefer that we don't try to do stuff to make KVM kinda-sorta-work on random 32-bit boards by stuffing in a not-the-right-type CPU, because this increases our security boundary massively. At the moment we can reasonably say "only the 'virt' board and one of the Xilinx boards are security-critical". thanks -- PMM