From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Mon, 23 Mar 2009 20:51:36 +0000 (-0300)
Subject: KVM: x86: disable kvmclock on non constant TSC hosts
X-Git-Tag: v2.6.28.10~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dfccb2ea806875b9379f72af1a6f86f3811b2e88;p=thirdparty%2Fkernel%2Fstable.git

KVM: x86: disable kvmclock on non constant TSC hosts

(cherry picked from abe6655dd699069b53bcccbc65b2717f60203b12)

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6c7f4ab955de4..f1db5ba48a276 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -906,7 +906,6 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_USER_MEMORY:
 	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:
@@ -931,6 +930,9 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_IOMMU:
 		r = intel_iommu_found();
 		break;
+	case KVM_CAP_CLOCKSOURCE:
+		r = boot_cpu_has(X86_FEATURE_CONSTANT_TSC);
+		break;
 	default:
 		r = 0;
 		break;