From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: [patch 02/16] x86: pvclock: make sure rdtsc doesnt speculate out of region Date: Wed, 31 Oct 2012 20:46:58 -0200 Message-ID: <20121031224823.907464421@redhat.com> References: <20121031224656.417434866@redhat.com> Cc: johnstul@us.ibm.com, jeremy@goop.org, glommer@parallels.com, zamsden@gmail.com, gleb@redhat.com, avi@redhat.com, pbonzini@redhat.com, Marcelo Tosatti To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33825 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760981Ab2JaWrD (ORCPT ); Wed, 31 Oct 2012 18:47:03 -0400 Content-Disposition: inline; filename=01-pvclock-read-rdtsc-barrier Sender: kvm-owner@vger.kernel.org List-ID: Originally from Jeremy Fitzhardinge. pvclock_get_time_values, which contains the memory barriers will be removed by next patch. Signed-off-by: Marcelo Tosatti Index: vsyscall/arch/x86/kernel/pvclock.c =================================================================== --- vsyscall.orig/arch/x86/kernel/pvclock.c +++ vsyscall/arch/x86/kernel/pvclock.c @@ -97,10 +97,10 @@ cycle_t pvclock_clocksource_read(struct do { version = pvclock_get_time_values(&shadow, src); - barrier(); + rdtsc_barrier(); offset = pvclock_get_nsec_offset(&shadow); ret = shadow.system_timestamp + offset; - barrier(); + rdtsc_barrier(); } while (version != src->version); if ((valid_flags & PVCLOCK_TSC_STABLE_BIT) &&