* Andi Kleen <ak@xxxxxxx> wrote:
I think we would need to have a paravirt ops callback to decide this first. But it doesn't look critical to me anyways.
well, it's critical to me in two ways: 1) to make the i386 paravirt code clean 2) to have a proper VDSO for a KVM paravirtual guest. The original change is also bad because it changes how a Linux guest behaves: it turns off the vdso by default, and disables the compat VDSO. I.e. it's a bad performance step backwards if CONFIG_PARAVIRT is enabled (uses int $0x80 instead of sysenter), which hurts only KVM and basically none of the other hypervisors. It also muddifies the VDSO picture wrt. virtualization.