DR7_GD
if (ctxt->ops->get_effective_dr7(ctxt) & DR7_GD)
if (vcpu->arch.dr7 & DR7_GD) {
vcpu->arch.dr7 &= ~DR7_GD;
if (dr7 & DR7_GD) {
vcpu->arch.dr7 & DR7_GD) {
vcpu->arch.dr7 &= ~DR7_GD;
debug.arch.debugreg[7] = 0x400 | DR7_GD;