From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [RFC 9/9] KVM: KVM_VFIO: ARM: implement irq forwarding control Date: Wed, 27 Aug 2014 17:24:26 +0200 Message-ID: <53FDF82A.4090606@linaro.org> References: <1408973264-30384-1-git-send-email-eric.auger@linaro.org> <1408973264-30384-10-git-send-email-eric.auger@linaro.org> <1409079769.2906.131.camel@ul30vt.home> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: eric.auger@st.com, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, joel.schopp@amd.com, kim.phillips@freescale.com, linux-kernel@vger.kernel.org, patches@linaro.org, will.deacon@arm.com, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, john.liuli@huawei.com To: Alex Williamson Return-path: Received: from mail-we0-f175.google.com ([74.125.82.175]:36834 "EHLO mail-we0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935482AbaH0PYx (ORCPT ); Wed, 27 Aug 2014 11:24:53 -0400 Received: by mail-we0-f175.google.com with SMTP id t60so373843wes.20 for ; Wed, 27 Aug 2014 08:24:49 -0700 (PDT) In-Reply-To: <1409079769.2906.131.camel@ul30vt.home> Sender: kvm-owner@vger.kernel.org List-ID: On 08/26/2014 09:02 PM, Alex Williamson wrote: > On Mon, 2014-08-25 at 15:27 +0200, Eric Auger wrote: >> Implements ARM specific KVM-VFIO device group commands: >> - KVM_DEV_VFIO_DEVICE_ASSIGN_IRQ >> - KVM_DEV_VFIO_DEVICE_DEASSIGN_IRQ >> capability can be queried using KVM_HAS_DEVICE_ATTR. >> >> The new commands enable to set IRQ forwarding on/off for a given >> IRQ index of a VFIO platform device. >> >> as soon as a forwarded irq is set, a reference to the VFIO device >> is taken by the kvm-vfio device. >> >> The kvm-vfio device stores in the kvm_vfio_arch_data the list >> of "assigned" devices (kvm_vfio_device). Each kvm_vfio_device >> stores the list of assigned IRQs (potentially allowed a subset of >> IRQ to be forwarded) >> >> The kvm-vfio device programs both the GIC and vGIC. Also it >> clears the active bit on destruction, in case the guest did not >> do it itself. >> >> Changing the forwarded state is not allowed in the critical >> section starting from VFIO IRQ handler to LR programming. It is >> up to the client to take care of this. >> >> Signed-off-by: Eric Auger >> --- >> arch/arm/include/asm/kvm_host.h | 2 + >> arch/arm/kvm/Makefile | 2 +- >> arch/arm/kvm/kvm_vfio_arm.c | 599 ++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 602 insertions(+), 1 deletion(-) >> create mode 100644 arch/arm/kvm/kvm_vfio_arm.c > > I'm really happy that it seems like the kvm-vfio device is going to work > for you, but I think too much stuff is being pushed out to arch code > here. Exporting the interfaces in patches 7 & 8 are setting the stage > for duplicate code for anyone wanting to implement device attributes. > Instead, I think the core code should support the list of > kvm_vfio_devices with proper cleanup, and we should attempt to access > the kvm_vfio_ callbacks as little as possible from arch code. Thanks, OK. my next iteration will feature much more generic code. Thanks for the review Best Regards Eric > > Alex >