[libvirt] About virtualization, libvirt and xen...

Hello, I have understand that : ---------------------------- guest ---------------------------- driver_device0_guest ---------------------------- hypervisor ---------------------------- driver_device0_hypervisor ---------------------------- device0 ---------------------------- in order to access to a device, a guest use driver_device0_guest The driver_device0_guest is modified to ask the hypervisor instead of the device0 directly. Then the hypervisor uses the driver_device0_hypervisor in order to ask the device0. It's my understant, maybe it's false. I have few questions : 1 - what is the difference between libvirt and virtio. 2 - why developpers for xen, kvm... must develop drivers each time there are new devices ? Because the driver must ask the hypervisor instead of device directly. 3 - The devices presented to the guest are real or emulated ? (for xen and/or kvm) if devices are real, for example, i can use my graphic card with a virtual machine ?? 4 - Can you tell me why kvm is best or xen is best in enterprise. In my understand, in the future, kvm is in good position because the developpment is integrated in the kernel. Also, i feel xen progress because firms like citrix contribute but it's seems there is no big update since few years. My vision is xen is best for production environnement because it takes advantages of minimal hypervisor code while kvm must be install with the kernel. Also, it seems, performance will be better in kvm with virtio. Can we use virtio with xen ? _________________________________________________________________ Vous voulez savoir ce que vous pouvez faire avec le nouveau Windows Live ? Lancez-vous ! http://www.microsoft.com/windows/windowslive/default.aspx