On Wed, Aug 03, 2011 at 11:41:42AM +0200, Andre Przywara wrote: > Hi, > > while looking through the code I found commit > f79116867ec80ed5d1d10043a3fd9ac8afd182c1 (upstream QEMU: enable > SMEP) which unconditionally propagates the bits from CPUID leaf 0x7 > to the guest. Though there is the KVM module in the line, this > currently whitelists three feature bits. > Doesn't that break migration? The result of the CPUID instruction > the guess issues only depends on the host and the KVM module's > policy, not on the CPU model QEMU uses. So I guess migrating from a > newer CPU to an older one breaks despite a rather conservative CPU > model has been chosen intentionally by the user. > The same is probably true for the VIA CPUID leaf. > > Is that considered OK now or is that a bug? Shall the new feature > bits be made known to QEMU like the other ones on only enabled > explicitly (+smep) or by -cpu host? > I can make a patch for that if that is the right way to address this. Or if the CPU type supports it, yes. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
