diff --git a/sys/amd64/vmm/vmm.c b/sys/amd64/vmm/vmm.c --- a/sys/amd64/vmm/vmm.c +++ b/sys/amd64/vmm/vmm.c @@ -2804,10 +2804,12 @@ static int vm_snapshot_vcpus(struct vm *vm, struct vm_snapshot_meta *meta) { + uint64_t tsc, now; int ret; int i; struct vcpu *vcpu; + now = rdtsc(); for (i = 0; i < VM_MAXCPU; i++) { vcpu = &vm->vcpu[i]; @@ -2819,13 +2821,15 @@ SNAPSHOT_VAR_OR_LEAVE(vcpu->guest_xcr0, meta, ret, done); SNAPSHOT_VAR_OR_LEAVE(vcpu->exitinfo, meta, ret, done); SNAPSHOT_VAR_OR_LEAVE(vcpu->nextrip, meta, ret, done); - /* XXX we're cheating here, since the value of tsc_offset as - * saved here is actually the value of the guest's TSC value. + + /* + * Save the absolute TSC value by adding now to tsc_offset. * * It will be turned turned back into an actual offset when the * TSC restore function is called */ - SNAPSHOT_VAR_OR_LEAVE(vcpu->tsc_offset, meta, ret, done); + tsc = now + vcpu->tsc_offset; + SNAPSHOT_VAR_OR_LEAVE(tsc, meta, ret, done); } done: @@ -2836,33 +2840,10 @@ vm_snapshot_vm(struct vm *vm, struct vm_snapshot_meta *meta) { int ret; - int i; - uint64_t now; - - ret = 0; - now = rdtsc(); - - if (meta->op == VM_SNAPSHOT_SAVE) { - /* XXX make tsc_offset take the value TSC proper as seen by the - * guest - */ - for (i = 0; i < VM_MAXCPU; i++) - vm->vcpu[i].tsc_offset += now; - } ret = vm_snapshot_vcpus(vm, meta); - if (ret != 0) { - printf("%s: failed to copy vm data to user buffer", __func__); + if (ret != 0) goto done; - } - - if (meta->op == VM_SNAPSHOT_SAVE) { - /* XXX turn tsc_offset back into an offset; actual value is only - * required for restore; using it otherwise would be wrong - */ - for (i = 0; i < VM_MAXCPU; i++) - vm->vcpu[i].tsc_offset -= now; - } done: return (ret);