Hypervisors are moving in the direction that soon they will be built into the maintstream Mobo, in fact Dell and HP, and I think IBM, have XenServer built into the BIOS already. This means that in addition to the usual boot commands: C:>CDROM>USB>PXE, you now have an option to boot directly into Xen. A security concern could be that the virus somehow brings up a malicious VM; but the chances are really small....
So, not sure what the security issues you talking of: another industry concern is that the Hypervisor could be compromised by a virus and thus impact all the VMs. Of course the Hypervisor is Linux
As to the rewriting of the kernel, it is not necessary to make any modifications to the OS (one of the huge benefits of virtualisation). The Hypervisor is used to paravirtualise the underlying hardware, so the OS should not know the difference. In fact, as mentioned above, the Hypervisor is quickly becoming a hardware component; as apposed to software component....
So, not sure what the security issues you talking of: another industry concern is that the Hypervisor could be compromised by a virus and thus impact all the VMs. Of course the Hypervisor is Linux
As to the rewriting of the kernel, it is not necessary to make any modifications to the OS (one of the huge benefits of virtualisation). The Hypervisor is used to paravirtualise the underlying hardware, so the OS should not know the difference. In fact, as mentioned above, the Hypervisor is quickly becoming a hardware component; as apposed to software component....