From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yang, Sheng" Subject: Re: [PATCH 2/2] [PATCH] disable kvm clock unless addr's LSB is set. Date: Sat, 8 Mar 2008 11:39:17 +0800 Message-ID: <200803081139.17367.sheng.yang@intel.com> References: <1204814744-12595-1-git-send-email-gcosta@redhat.com> <1204814744-12595-2-git-send-email-gcosta@redhat.com> <1204814744-12595-3-git-send-email-gcosta@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: chrisw@sous-sol.org, avi@qumranet.com, Glauber Costa To: kvm-devel@lists.sourceforge.net Return-path: In-Reply-To: <1204814744-12595-3-git-send-email-gcosta@redhat.com> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org On Thursday 06 March 2008 22:45:44 Glauber Costa wrote: > Use LSB of the address passed through the msr to enable/disable > the clock. Setting it to 1 enables it, setting it to 0 disables it. > > As the guest data structures are aligned anyway, this > won't be a problem, as this bit is free. > > Guest is changed accordingly > > Signed-off-by: Glauber Costa > --- > arch/x86/kernel/kvmclock.c | 2 +- > arch/x86/kvm/x86.c | 9 ++++++++- > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index 7c481a3..f654a12 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -125,7 +125,7 @@ static int kvm_register_clock(void) > { > int cpu = smp_processor_id(); > int low, high; > - low = (int)__pa(&per_cpu(hv_clock, cpu)); > + low = (int)__pa(&per_cpu(hv_clock, cpu)) | 1; > high = ((u64)__pa(&per_cpu(hv_clock, cpu)) >> 32); > > return native_write_msr_safe(MSR_KVM_SYSTEM_TIME, low, high); > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 6abd784..64beff6 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -591,8 +591,15 @@ int kvm_set_msr_common(struct kvm_vcpu * > if (vcpu->arch.time_page) > kvm_release_page_dirty(vcpu->arch.time_page); > > + /* we verify if the enable bit is set... */ > + if (!(data & 1)) { > + vcpu->arch.time = NULL; This line made compiler complaining... Thanks Yang, Sheng ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/