On 2/18/21 5:51 AM, Roger Pau Monné wrote: > On Wed, Jan 20, 2021 at 05:49:10PM -0500, Boris Ostrovsky wrote: >> When toolstack updates MSR policy, this MSR offset (which is the last >> index in the hypervisor MSR range) is used to indicate hypervisor >> behavior when guest accesses an MSR which is not explicitly emulated. > It's kind of weird to use an MSR to store this. I assume this is done > for migration reasons?
Not really. It just seemed to me that MSR policy is the logical place to do that. Because it *is* a policy of how to deal with such accesses, isn't it? > Isn't is possible to convey this data in the xl migration stream > instead of having to pack it with MSRs? I haven't looked at this but again --- the feature itself has nothing to do with migration. The fact that folding it into policy makes migration of this information "just work" is just a nice side benefit of this implementation. -boris
