From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] x86: kvmclock: Do not setup kvmclock vsyscall in the absence of that clock Date: Wed, 27 Feb 2013 13:19:55 +0200 Message-ID: <20130227111955.GC23616@redhat.com> References: <5128E8C9.1050000@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Marcelo Tosatti , kvm To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8760 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758614Ab3B0LT4 (ORCPT ); Wed, 27 Feb 2013 06:19:56 -0500 Content-Disposition: inline In-Reply-To: <5128E8C9.1050000@web.de> Sender: kvm-owner@vger.kernel.org List-ID: On Sat, Feb 23, 2013 at 05:05:29PM +0100, Jan Kiszka wrote: > From: Jan Kiszka > > This fixes boot lockups with "no-kvmclock", when the host is not > exposing this particular feature (QEMU: -cpu ...,-kvmclock) or when > the kvmclock initialization failed for whatever reason. > > Signed-off-by: Jan Kiszka Applied, thanks. > --- > > Should go to 3.8 as well, I presume. > > arch/x86/kernel/kvmclock.c | 9 ++++++++- > 1 files changed, 8 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index 5bedbdd..b730efa 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -160,8 +160,12 @@ int kvm_register_clock(char *txt) > { > int cpu = smp_processor_id(); > int low, high, ret; > - struct pvclock_vcpu_time_info *src = &hv_clock[cpu].pvti; > + struct pvclock_vcpu_time_info *src; > + > + if (!hv_clock) > + return 0; > > + src = &hv_clock[cpu].pvti; > low = (int)__pa(src) | 1; > high = ((u64)__pa(src) >> 32); > ret = native_write_msr_safe(msr_kvm_system_time, low, high); > @@ -276,6 +280,9 @@ int __init kvm_setup_vsyscall_timeinfo(void) > struct pvclock_vcpu_time_info *vcpu_time; > unsigned int size; > > + if (!hv_clock) > + return 0; > + > size = PAGE_ALIGN(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS); > > preempt_disable(); > -- > 1.7.3.4 > -- Gleb.