On Feb 03 15:26, Peter Maydell wrote: > On Wed, 3 Feb 2021 at 15:11, Dr. David Alan Gilbert <dgilb...@redhat.com> > wrote: > > It's interesting that on x86 we've got a longterm request to *add* cpu > > features to the stream to detect screwups caused by using mismatched > > CPUs; so it's not necessarily a bad idea to include it once you realise > > it's there. > > I think we would want to do that by checking the ID registers, > not the legacy ad-hoc feature-flags word. In fact I think for > KVM at least we already perform the check on the ID registers, > in that the kernel will return an error if we pass it a value > for an ID register and it's not the value it should be. > I forget whether we try to check this for TCG (the mechanism > for handling sysreg migration there is different).
Ah, I sent my reply where I mentioned attempting to find a way to selectively check env.features before I saw this. I'll just send the patch for `VMSTATE_UNUSED(sizeof(uint64_t))`. -Aaron
