[$] Direct host system calls from KVM

As a general rule, virtualization mechanisms are designed to provide strongisolation between a host and the guest systems that it runs. The guestsare not trusted, and their ability to access or influence anything outsideof their virtual machines must be tightly controlled. So a patch seriesallowing guests to execute arbitrary system calls in the host context mightbe expected to be the cause of significantly elevated eyebrows across thenet. Andrei Vagin has posted such aseries with the expected results.