On Fri, Mar 16, 2007 at 09:03:08AM -0500, Anthony Liguori wrote: > Heiko Carstens wrote: > >On Sun, Mar 11, 2007 at 03:53:12PM +0200, Avi Kivity wrote: > > > >>This patchset updates the kvm userspace interface to what I hope will > >>be the long-term stable interface. Provisions are included for extending > >>the interface later. The patches address performance and cleanliness > >>concerns. > >> > > > >Searching the mailing list I figured that as soons as the interface seems > >to be stable, kvm should/would switch to a system call based interface. > >I assume the userspace interface might still change a lot, especially if > >kvm is ported to new architectures. > >But the general question is: do you still plan to switch to a syscall > >interface? > > > > What benefit would a syscall interface have?
First of all: it's faster and doesn't burn a bunch of additional cpu cycles like sys_ioctl and the large switch statements do. Another thing is that this patch set already introduces a way to pass a sigset. Passing a sigset to a device node is sort of strange. In addition, if we would port kvm to s390, then we would need to make sure that each virtual cpu only gets executed from the thread that created it. That is simply because the upper half of our page tables contain information about the guest page states. This is yet another thing that would be strange to do via an ioctl based interface. Of course everthing can be done via an iotcl interface too, but IMHO that's just the wrong interface. ------------------------------------------------------------------------- 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
