Avi Kivity wrote: >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index 148ed66..0e64997 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -2210,7 +2210,11 @@ int kvm_dev_ioctl_check_extension(long ext) >> r = kvm_has_tsc_control; break; >> case KVM_CAP_TSC_DEADLINE_TIMER: >> +#ifdef CONFIG_HIGH_RES_TIMERS >> r = boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER); +#else >> + r = 0; >> +#endif >> break; > > I prefer a patch making kvm for x86 depend on hrtimers. kvm already > provides a high resolution timer to the guest in the local apic, > backing it with the jiffies event source will likely cause some > guests to malfunction. Yep, I did a draft test for kvm lapic timer, it also worked fail when CONFIG_HIGH_RES_TIMERS disabled. Attached is the udpated patch. Thanks, Jinsong ==================== >From 64d0458ec50a7d6917adf1e9735ba6e6ae6024ad Mon Sep 17 00:00:00 2001 From: Liu, Jinsong <jinsong.liu@xxxxxxxxx> Date: Sat, 8 Sep 2012 03:32:31 +0800 Subject: [PATCH] KVM: select HIGH_RES_TIMERS when KVM enabled This is for 2 reasons: 1. it's pointless for kvm lapic timer and tsc deadline timer when kernel hrtimer not configured as high resolution, since that would be not accurate based on wheel; 2. 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 | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index a28f338..5f861ca 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -24,6 +24,8 @@ config KVM depends on PCI # for TASKSTATS/TASK_DELAY_ACCT: depends on NET + # for HIGH_RES_TIMERS + depends on !ARCH_USES_GETTIMEOFFSET select PREEMPT_NOTIFIERS select MMU_NOTIFIER select ANON_INODES @@ -37,6 +39,8 @@ config KVM select TASK_DELAY_ACCT select PERF_EVENTS select HAVE_KVM_MSI + select GENERIC_CLOCKEVENTS + select HIGH_RES_TIMERS ---help--- Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent -- 1.7.1
Attachment:
0001-KVM-select-HIGH_RES_TIMERS-when-KVM-enabled.patch
Description: 0001-KVM-select-HIGH_RES_TIMERS-when-KVM-enabled.patch
