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I think paravirtualization just means that there are drivers installed on the guest OS that make the interaction with hardware faster (perhaps reduce the numbe
by exacube 11y ago
I think paravirtualization just means that there are drivers installed on the guest OS that make the interaction with hardware faster (perhaps reduce the number of copies and/or interrupts) by being cooperative.
Paravirtualization is just an extension of what you think is "full virtualization"
BTW, In case this article was misleading: I think Xen already has paravirt support that VPS providers already take advantage of.
- cthalupa 11y agoParavirtualization is not an extension of full virtualization. If anything, it's moving in the other direction - instead of virtualizing the parts of the system that are difficult or low performance when virtualized, you instead offer up a software device. In practice, this is generally your IO devices - without SR-IOV support, your IO is quite slow through an emulated device. Paravirtual IO drivers, you have a front end driver in the guest, and a back end driver elsewhere. In Xen, this is a dom0 or stub domain that also includes the actual hardware driver. With Xen the front end and back end are just a shared memory segment using a ring buffer. KVM does things a bit differently, but the core concept is pretty similar. SR-IOV you have a virtual function of the device that is passed through directly to the guest, eliminating the need for the PV IO drivers at all.
- exacube 11y agoThanks for the clarification!