Tomasz Chmielewski wrote: > As I understand, fully virtualized KVM guests (on Intel VT or AMD-V) can > perform with near native speeds only when it comes to the CPU - because > the things like network or block device are basically emulated. > > > Among many changes, KVM in 2.6.21 has "Initial paravirtualization > support, which has much faster performance", and is based on KVM-15. > > > At least two PV drivers are needed: > - network > - block device >
I don't believe a PV block driver is actually necessary. Disk devices are actually quite slow (unless you have a large array). With a few small changes (bump MMU cache up to 1024 and actually enable the aio subsystem), SCSI emulation does as well as Xen's PV block driver (about 210 mb/sec whereas native is around 250 mb/sec). There's a lot of room to optimize the SCSI emulation too since there are a number of copies in that path. The SCSI emulation is a lot like what one would design in a PV driver. It supports multiple outstanding requests and doesn't require a whole lot of exits to submit a request (it uses scripts). Regards, Anthony Liguori > > What is the state of these PV drivers now? Is it usable on Linux now? > > Are Windows PV drivers planned, too? If yes, who is going to take the > lead here (Qumranet, community, not decided yet etc.?). > > > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ kvm-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/kvm-devel
