From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v7] arm/arm64: KVM: Detect vGIC presence at runtime Date: Fri, 18 Dec 2015 12:34:08 +0000 Message-ID: <20151218123408.77b0dd12@arm.com> References: <01b201d13988$a73a3400$f5ae9c00$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org To: Pavel Fedin Return-path: Received: from foss.arm.com ([217.140.101.70]:39729 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752670AbbLRMeN (ORCPT ); Fri, 18 Dec 2015 07:34:13 -0500 In-Reply-To: <01b201d13988$a73a3400$f5ae9c00$@samsung.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, 18 Dec 2015 14:38:43 +0300 Pavel Fedin wrote: > Before commit 662d9715840aef44dcb573b0f9fab9e8319c868a > ("arm/arm64: KVM: Kill CONFIG_KVM_ARM_{VGIC,TIMER}") is was possible to > compile the kernel without vGIC and vTimer support. Commit message says > about possibility to detect vGIC support in runtime, but this has never > been implemented. > > This patch introduces runtime check, restoring the lost functionality. > It again allows to use KVM on hardware without vGIC. Interrupt > controller has to be emulated in userspace in this case. > > -ENODEV return code from probe function means there's no GIC at all. > -ENXIO happens when, for example, there is GIC node in the device tree, > but it does not specify vGIC resources. Any other error code is still > treated as full stop because it might mean some really serious problems. > > Signed-off-by: Pavel Fedin > Reviewed-by: Christoffer Dall Applied. Thanks, M. -- Jazz is not dead. It just smells funny.