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: kvm-84rc1~3
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=19aaa5d1e4445ee75622463813d10e67f9102217;p=users%2Fdwmw2%2Flinux.git

KVM: x86: disable kvmclock on non constant TSC hosts

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 8cb6e3f3f3103..8f83590b47dd1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1000,7 +1000,6 @@ 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:
@@ -1026,6 +1025,9 @@ 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;