On Sun, Aug 15, 2010 at 06:58:06PM +0300, Avi Kivity wrote: > On 08/15/2010 03:49 PM, Gleb Natapov wrote: > >> > >>True. Can we do it for real mode in general (i.e. X86EMUL_MODE_REAL)? > >If we flush all shadow pages when moving from paged mode to non paged > >checking for X86EMUL_MODE_REAL sounds enough to me, but Avi knows better. > >Or we can add is_big_real_mode() callback to x86_ops and implement it in > >vmx accordingly. > > Neither are possible. We can have one cpu in big real mode and > others in paged mode, so even in real mode we cannot rule out a > spurious page fault due to shadow write protection. > Correct, just checking X86EMUL_MODE_REAL is not enough due to smp, but why checking for big real mode will not work? If instruction can't be emulated while vcpu is in big real mode returning to vcpu is not an option, so kvm will fail anyway. -- Gleb. -- 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
