From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Evans Subject: Re: [PATCH V2 0/2] kvm tools: PPC64 basic support Date: Wed, 14 Dec 2011 11:34:00 +1100 Message-ID: <4EE7EEF8.9090804@ozlabs.org> References: <1323759627-12752-1-git-send-email-matt@ozlabs.org> <1323771792.3263.1.camel@lappy> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, penberg@kernel.org, asias.hejun@gmail.com, gorcunov@gmail.com, Alexander Graf To: Sasha Levin Return-path: In-Reply-To: <1323771792.3263.1.camel@lappy> Sender: kvm-ppc-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 13/12/11 21:23, Sasha Levin wrote: > On Tue, 2011-12-13 at 18:00 +1100, Matt Evans wrote: >> The second patch is a small fix for generic virtio code (now that we have a >> PPC build) which removes reliance on ioeventfds for PPC, which doesn't provide >> them. > > Hm... ioeventfds are located in the generic code and should be available > on all archs (it doesn't use any arch specific code at all afaik). > > Why don't they work on ppc? > Well, there are two problems: you're right that it's generic code, but it's configurable and CONFIG_HAVE_KVM_EVENTFD isn't set for PPC KVM (thus the ioctl fails). That's probably off because ioevents won't work anyway-- the in-kernel MMIO exit route isn't wired up to kvm_io_bus_read/write() yet. (It looks like KVM_IRQFD will also fail, which virtio-pci /would/ use if I supported MSIs, which I currently don't.) Yes, this can be fixed, but relying on it means that virtio on kvmtool/PPC won't work on today's kernels. :( Cheers, Matt