Avi Kivity wrote: > On 09/09/2012 05:54 PM, Liu, Jinsong wrote: >>> >>> hrtimers is an intrusive feature, I don't think we should >>> force-enable it. Please change it to a depends on. >> >> Hmm, if it changed as >> config KVM >> depends on HIGH_RES_TIMERS >> The item 'Kernel-based Virtual Machine (KVM) support (NEW)' even >> didn't appear to user when make menuconfig (when HIGH_RES_TIMERS >> disable) >> >> Is it good? I just have a little concern here:) > > It's not good, but that's what we have. > > It's okay to force-enable low-impact features (like preempt notifies). > > hrimers, on the other hand, change kernel behaviour quite deeply. > > Maybe over time someone will fix the config tools to unhide features > that can be enabled by turning on a dependency. OK, updated as attached. Thanks, Jinsong =============== >From e6c2a80d3111cc6fb992d78b242619706d99bc6b Mon Sep 17 00:00:00 2001 From: Liu, Jinsong <jinsong.liu@xxxxxxxxx> Date: Mon, 10 Sep 2012 06:55:39 +0800 Subject: [PATCH] KVM: KVM enable depends on HIGH_RES_TIMERS KVM lapic timer and tsc deadline timer based on hrtimer, setting a leftmost node to rb tree and then do hrtimer reprogram. If hrtimer not configured as high resolution, hrtimer_enqueue_reprogram do nothing and then make kvm lapic timer and tsc deadline timer fail. Signed-off-by: Liu, Jinsong <jinsong.liu@xxxxxxxxx> --- arch/x86/kvm/Kconfig | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index a28f338..65657ec 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -20,6 +20,7 @@ if VIRTUALIZATION config KVM tristate "Kernel-based Virtual Machine (KVM) support" depends on HAVE_KVM + depends on HIGH_RES_TIMERS # for device assignment: depends on PCI # for TASKSTATS/TASK_DELAY_ACCT: -- 1.7.1
Attachment:
0001-KVM-KVM-enable-depends-on-HIGH_RES_TIMERS.patch
Description: 0001-KVM-KVM-enable-depends-on-HIGH_RES_TIMERS.patch
