On Wed, 2012-07-11 at 10:52 -0600, Chris Friesen wrote: > Hi, > > We're running into a problem where we can't start up a single instance > of kvm-qemu with 5 or more virtual functions (for the ethernet card) > being passed to the guest. It's an Intel I350 NIC if it matters. > > I noticed a discussion in a thread titled "[RFC PATCH 0/2] Expose > available KVM free memory slot count to help avoid aborts" that seemed > to point to the hardcoded definition of KVM_MEMORY_SLOTS as being a > possible problem, and proposed some patches to allow dynamic sizing of > the number of memory slots. It looks like that patch never went through > to mainline though. > > Is this likely the source of my problem? Yes, that's the problem. > Why didn't it ever get submitted to mainline. There were issues with extending the number of available memory slots. By itself, those patches just prevent an abort, but don't really let you add more devices. > What's the proper method of supporting 8 VFs per VM, with possibly > several VMs? The limiting factor to increasing memory slots was searching the array. That's since been fixed by caching mmio page table entries. AIUI, Avi is now willing to accept a patch to bump memory slots to a much higher value. The number of available slots can be queried by qemu using KVM_CAP_NR_MEMSLOTS, then something like the RFC you point at could be used to allow device assignment to take advantage of that. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
