From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH 0/3] KVM: arm: Implement software vGICv2 emulation Date: Mon, 29 Jun 2015 14:52:13 +0200 Message-ID: <20150629125213.GK11332@cbox> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, Marc Zyngier , Andre Przywara To: Pavel Fedin Return-path: Received: from mail-la0-f52.google.com ([209.85.215.52]:35690 "EHLO mail-la0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752918AbbF2MwQ (ORCPT ); Mon, 29 Jun 2015 08:52:16 -0400 Received: by lagh6 with SMTP id h6so52324975lag.2 for ; Mon, 29 Jun 2015 05:52:15 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: Hi Pavel, [Please cc the kvm/arm list for such patches according to the MAINTAINERS file in the future] On Mon, Jun 29, 2015 at 12:53:46PM +0300, Pavel Fedin wrote: > Some hardware (like Raspberry Pi 2) is capable of running KVM, however lacks > functional vGIC registers. This series introduces software vGIC emulation for > such machines, allowing to fully use virtualization capabilities Is this rather esoteric use case really worth the extra code in the kernel? I really feel that pure emulation should happen in userspace unless there's a very good reason for doing it in the kernel, such as a clearly measureable difference in performance, etc. I would much rather see a version of this where a userspace provided GIC works with the in-kernel arch timers support. -Christoffer