On Mon, 2008-09-22 at 15:15 -0700, David Miller wrote: > From: Hollis Blanchard <hollisb@xxxxxxxxxx> > Date: Mon, 22 Sep 2008 16:27:40 -0500 > > > On Mon, 2008-09-22 at 15:31 -0500, Javier Guerra wrote: > > > On Mon, Sep 22, 2008 at 3:18 PM, Hollis Blanchard <hollisb@xxxxxxxxxx> wrote: > > > > It would be even more interesting to implement host support on the Sparc > > > > processors with hardware virtualization support. > > > > > > Does Sparc processors also have 'virtualization support' as an extra > > > feature? i thought that 'non virtualizationability' was an > > > intel-specific limitation. (come on... creating a privileged mode and > > > not trapping violations? who else would design like that?) > > > > Trapping on privileged instructions is enough to get you virtualization > > functionality, but for good performance you really want additional > > hardware support to avoid those traps in the first place. > > That's not really available on sparc. As far as I can see, you have a hypervisor privilege mode which allows your guests to execute privileged instructions like WRPR without trapping. Without that hardware support (with only 2 privilege levels), you'd be forced to run the guest kernel in user mode, trapping on every WRPR (for example). That's what I mean by hardware helping you to avoid traps. -- Hollis Blanchard IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
