On Tue, 10 Sep 2024 08:16:49 +0100, Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> wrote: > > And now to the elephant in the room, handling MIDR differences and associated errata > management 😊 > > Marc, you mentioned about a prototype solution you have a while back[0], > has that been shared public? Nah, and I didn't have any time to get back to it. But maybe that's a KVM Forum hackathon project! To be honest, this has little to do with KVM itself. It is mostly guest enlightenment and a bit of infrastructure to communicate the constraints back to the guest. > Also not sure ARM has any plans to make this a specification soon. Probably not until we come up with a decent prototype that solves the problem. > I was thinking of handling this in userspace for now by ignoring the MIDR write > error on Migration and keeping the host MIDR value for destination VM. This is > for use cases where we know that the hosts doesn't have any MIDR based errata or > errata difference doesn't matter and assuming the user knows what they are doing. If you know of *any* host that doesn't have errata to be mitigated in the guest, send it to me, and I'll find you one pretty quickly! :D But yes, you can always play that game (which is what I do for big-little by letting the guest migrating between CPU types). But it is ultimately doomed. > Please let me know, if there are any other suggestions or work in progress on this one. I don't have much free time at the moment, but I'll do what I can. Thanks, M. -- Without deviation from the norm, progress is not possible.
