On Wed, Jan 20, 2010 at 12:04:31AM +0200, Etzion Bar-Noy wrote: > PV drivers were released by Oracle, who run their own virtualization > platform based on XenCommunity. > > KVM is wasteful and requires VT support even for Linux machines. Not > only that, but its virtualized hardware is legacy old hardware > supplied by QEMU.
Sorry Etzion, but that's wrong on multiple levels. First, VT support isn't "wasteful", it's using the processor to do what it does best (compared to software)---virtualize the machine. Second, KVM uses para-virtualization judiciously *in addition* to VT to get an additional performance boost where it makes sense. There aren't too many such places, surprisingly enough. C.f.'s VMware's recent request to remove their para-virtualization (VMI) layer from the Linux kernel, because "new hardware is fast enough that it doesn't buy you anything". Second, the virtualized hardware for *both* Xen and KVM is provided by QEMU. One difference between them is that he KVM developers are actively improving QEMU (in fact, the current QEMU maintainer is one of the main KVM developer). Third, the "virtualized hardware" provided by QEMU is not very interesting---for anything performance sensitive both Xen and QEMU provide para-virtualized drivers and PCI device assignment. > KVM was designed, and is focused on VDI - desktop virtualization, > being the focus of Kumranet in the past. RedHat cannot maintain two > virtualization platforms. Again, that's wrong. KVM was not designed for VDI, although at its earliest days that was the primary use case. It was designed and is continuing to be designed by the Linux/KVM community as a general purpose, server and desktop, hypervisor. Can you show a specific technical area in which Xen is better today? I worked on both Xen and KVM, and KVM is better architected, better designed, better implemented, and has a better community. Cheers, Muli _______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
