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| author | Marcelo Tosatti | 2008-12-11 20:45:05 +0100 |
|---|---|---|
| committer | Avi Kivity | 2009-03-24 10:02:53 +0100 |
| commit | 53f658b3c33616a4997ee254311b335e59063289 (patch) | |
| tree | fbef1e51bfa096dd28a00b2449d567f2c3ab6fb9 /arch/x86/kvm/x86.c | |
| parent | KVM: MMU: Drop walk_shadow() (diff) | |
| download | kernel-qcow2-linux-53f658b3c33616a4997ee254311b335e59063289.tar.gz kernel-qcow2-linux-53f658b3c33616a4997ee254311b335e59063289.tar.xz kernel-qcow2-linux-53f658b3c33616a4997ee254311b335e59063289.zip | |
KVM: VMX: initialize TSC offset relative to vm creation time
VMX initializes the TSC offset for each vcpu at different times, and
also reinitializes it for vcpus other than 0 on APIC SIPI message.
This bug causes the TSC's to appear unsynchronized in the guest, even if
the host is good.
Older Linux kernels don't handle the situation very well, so
gettimeofday is likely to go backwards in time:
http://www.mail-archive.com/kvm@vger.kernel.org/msg02955.html
http://sourceforge.net/tracker/index.php?func=detail&aid=2025534&group_id=180599&atid=893831
Fix it by initializating the offset of each vcpu relative to vm creation
time, and moving it from vmx_vcpu_reset to vmx_vcpu_setup, out of the
APIC MP init path.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 873602b5edfd..3b2acfd72d7f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4170,6 +4170,8 @@ struct kvm *kvm_arch_create_vm(void) /* Reserve bit 0 of irq_sources_bitmap for userspace irq source */ set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap); + rdtscll(kvm->arch.vm_init_tsc); + return kvm; } |