From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Tue, 10 Feb 2009 22:59:45 +0000 (-0200)
Subject: KVM: x86: disable kvmclock on non constant TSC hosts
X-Git-Tag: v2.6.29-rc6~90^2~5
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=abe6655dd699069b53bcccbc65b2717f60203b12;p=linux.git

KVM: x86: disable kvmclock on non constant TSC hosts

This is better.

Currently, this code path is posing us big troubles,
and we won't have a decent patch in time. So, temporarily
disable it.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fc3e329f6ade..758b7a155ae9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -967,7 +967,6 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
 	case KVM_CAP_SET_TSS_ADDR:
 	case KVM_CAP_EXT_CPUID:
-	case KVM_CAP_CLOCKSOURCE:
 	case KVM_CAP_PIT:
 	case KVM_CAP_NOP_IO_DELAY:
 	case KVM_CAP_MP_STATE:
@@ -992,6 +991,9 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_IOMMU:
 		r = iommu_found();
 		break;
+	case KVM_CAP_CLOCKSOURCE:
+		r = boot_cpu_has(X86_FEATURE_CONSTANT_TSC);
+		break;
 	default:
 		r = 0;
 		break;