diff options
| author | Jason J. Herne <jjherne@us.ibm.com> | 2015-03-09 15:56:08 +0100 |
|---|---|---|
| committer | Cornelia Huck <cornelia.huck@de.ibm.com> | 2015-03-16 10:15:44 +0100 |
| commit | 3f9e59bb5358cd020c5be919129281d202a24058 (patch) | |
| tree | 1ef75941c80fc50fa87f7d5791082ce9794e5cf2 /target-s390x/kvm.c | |
| parent | ae4a2bd759d647dd6146d45e4a59a01cf34d6a4d (diff) | |
s390x/kvm: Guest Migration TOD clock synchronization
Synchronizes the guest TOD clock across a migration by sending the guest TOD
clock value to the destination system. If the guest TOD clock is not preserved
across a migration then the guest's view of time will snap backwards if the
destination host clock is behind the source host clock. This will cause the
guest to hang immediately upon resuming on the destination system.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Message-Id: <1425912968-54387-1-git-send-email-jfrei@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'target-s390x/kvm.c')
| -rw-r--r-- | target-s390x/kvm.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c index 896534bf95..b21a348805 100644 --- a/target-s390x/kvm.c +++ b/target-s390x/kvm.c @@ -486,6 +486,45 @@ int kvm_arch_get_registers(CPUState *cs) return 0; } +int kvm_s390_get_clock(uint8_t *tod_high, uint64_t *tod_low) +{ + int r; + struct kvm_device_attr attr = { + .group = KVM_S390_VM_TOD, + .attr = KVM_S390_VM_TOD_LOW, + .addr = (uint64_t)tod_low, + }; + + r = kvm_vm_ioctl(kvm_state, KVM_GET_DEVICE_ATTR, &attr); + if (r) { + return r; + } + + attr.attr = KVM_S390_VM_TOD_HIGH; + attr.addr = (uint64_t)tod_high; + return kvm_vm_ioctl(kvm_state, KVM_GET_DEVICE_ATTR, &attr); +} + +int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low) +{ + int r; + + struct kvm_device_attr attr = { + .group = KVM_S390_VM_TOD, + .attr = KVM_S390_VM_TOD_LOW, + .addr = (uint64_t)tod_low, + }; + + r = kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr); + if (r) { + return r; + } + + attr.attr = KVM_S390_VM_TOD_HIGH; + attr.addr = (uint64_t)tod_high; + return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr); +} + /* * Legacy layout for s390: * Older S390 KVM requires the topmost vma of the RAM to be |