On Sun, Dec 20, 2009 at 06:17:02PM +0100, Alexander Graf wrote: > > On 20.12.2009, at 17:56, Michael S. Tsirkin wrote: > > > On Sun, Dec 20, 2009 at 05:59:33PM +0200, Avi Kivity wrote: > >> On 12/20/2009 05:51 PM, Michael S. Tsirkin wrote: > >>> > >>>> Maybe we should make -cpu host the default. That will give the best > >>>> performance for casual users, more testing for newer features, and will > >>>> force management apps to treat migration much more seriously. The > >>>> downside is that casual users upgrading their machines might experience > >>>> issues with Windows. Feature compatibility is not just about migration. > >>>> > >>> This seems very aggressive. Can't we whitelist features that we know > >>> about? Further, doesn't KVM already do this? > >>> > >>> > >> > >> It does, but without -cpuid host you're stuck with qemu64 (kvm.ko > >> doesn't add features userspace didn't request). > > > > Hmm, then, shouldn't either kvm or qemu mask features that we do not > > emulate well enough to make windows not crash? > > -cpu host does that already, no? > > Alex
I expected so, but Avi here seems to say windows will crash if you use a new CPU with it ... -- MST
