Marcelo Tosatti wrote: > On Fri, May 09, 2008 at 10:40:47AM +0300, Avi Kivity wrote: > > >>> Unfortunately it can't use wait_event_interruptible() due to >>> vcpu_put/vcpu_load. >>> >>> >>> >> schedule() will call vcpu_put()/vcpu_load() for us through preempt >> notifiers. I feel a little uneasy about it, but no concreate reason why >> not to rely on it. >> > > The preempt notifiers hook call kvm_arch_vcpu_load / kvm_arch_vcpu_put, > which won't unlock the vcpu mutex, right? > >
Yes. > I worry about a possible deadlock where some other operation that > requires the vcpu mutex happens but the vcpu thread itself is in hlt. > Suppose the guest executed a busy-spin waiting for an interrupt instead of a hlt? We need to be able to handle that too. The best practice is to issue all vcpu ioctls from the thread that created the vcpu; this becomes mandatory if we ever switch to a syscall interface and remove the mutex. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
