On 11/15/2012 04:08 AM, Marcelo Tosatti wrote: > As noted by Gleb, not advertising SSE2 support implies > no RDTSC barriers. > > Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> And this gets a separate patch because? > Index: vsyscall/arch/x86/include/asm/pvclock.h > =================================================================== > --- vsyscall.orig/arch/x86/include/asm/pvclock.h > +++ vsyscall/arch/x86/include/asm/pvclock.h > @@ -74,6 +74,9 @@ unsigned __pvclock_read_cycles(const str > u8 ret_flags; > > version = src->version; > + /* Note: emulated platforms which do not advertise SSE2 support > + * result in kvmclock not using the necessary RDTSC barriers. > + */ And the expected effects are? Will it work in that case? Any precautions one must take? Is it safe for Xen? Is it safe for KVM? Those are the types of things I'd expect to see in a comment for something as subtle as this. > rdtsc_barrier(); > offset = pvclock_get_nsec_offset(src); > ret = src->system_time + offset; > -- 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
