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 6c7f4ab955de4a0c0e8457b999fdae141ac14e98..f1db5ba48a2761d2dee625bc797c37ab57243466 100644 (file)
--- 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;