On Tue, 2007-09-25 at 19:15 +0200, Dor Laor wrote: > At the moment it's not good enough, there is a potential race were the > guest optimistically turn off > the VRING_AVAIL_F_NO_INTERRUPT in the vring_restart and afterwards > finds there are more_used so > it consume them in the poll function. > If in the middle, packets arrive the host will see the flag is off and > send irq. > In that case the above irq handler will report IRQ_NONE.
Good point. On the one hand, reporting IRQ_NONE occasionally is not fatal. On the other, it'd be nice to get this right. > It's also not trivial to cancel the optimistic approach in the restart > function since then there might be another race > that will result in missing irq reaching the guest. I did it optimistically because otherwise we need two barriers (and still have a window). > I'll try to think of something better than a hypercall for switching > irq on/off. Erk. That would be v. bad... Thanks, Rusty. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
