On Wed, 2007-01-10 at 11:52 +0100, Ingo Molnar wrote: > * Avi Kivity <[EMAIL PROTECTED]> wrote: > > > If you have a CONFIG_PARAVIRT guest, I believe it will always be > > faster to run it without hardware assisted virtualization: > > > > - you cannot eliminate vmexits due to host interrupts > > - a hypercall will (probably) keep being more expensive than a syscall; > > it simply has a lot more work to do > > - cr3 switches for CONFIG_PARAVIRT syscalls (which are necessary on > > x86_64) will probably become very cheap with tagged tlbs > > but irq overhead is nothing in importance compared to basic syscall > overhead. KVM/HVM already runs guest kernel syscalls at native speed. > KVM/LL (or Xen) has to switch cr3s to enter guest kernel context
Err no, this isn't true. See Documentation/lhype.txt or various blog entries on the subject 8) Both Xen and lhype get native syscall speeds (within measurement error). Rusty. ------------------------------------------------------------------------- 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 kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
