[PATCH 05/18] Warn about unstable TSC

From: Zachary Amsden
Date: Mon Jul 12 2010 - 22:26:00 EST


If creating an SMP guest with unstable host TSC, issue a warning

Signed-off-by: Zachary Amsden <zamsden@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2d5b97a..36ef649 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5449,6 +5449,10 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
unsigned int id)
{
+ if (check_tsc_unstable() && id != 0)
+ printk_once(KERN_WARNING
+ "kvm: SMP vm created on host with unstable TSC; "
+ "guest TSC will not be reliable\n");
return kvm_x86_ops->vcpu_create(kvm, id);
}

--
1.7.1

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