Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752964AbbG0Mf0 (ORCPT ); Mon, 27 Jul 2015 08:35:26 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:58976 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412AbbG0MfZ (ORCPT ); Mon, 27 Jul 2015 08:35:25 -0400 X-IronPort-AV: E=Sophos;i="5.15,553,1432598400"; d="scan'208";a="287889470" Message-ID: <55B62588.3050502@citrix.com> Date: Mon, 27 Jul 2015 13:35:20 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: Julien Grall , CC: , , , , "Catalin Marinas" , Will Deacon , "Konrad Rzeszutek Wilk" , Boris Ostrovsky , Thomas Gleixner , "Ingo Molnar" , "H. Peter Anvin" , Subject: Re: [PATCH v2] xen/events: Support event channel rebind on ARM References: <1437996911-18985-1-git-send-email-julien.grall@citrix.com> In-Reply-To: <1437996911-18985-1-git-send-email-julien.grall@citrix.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1902 Lines: 49 On 27/07/15 12:35, Julien Grall wrote: > Currently, the event channel rebind code is gated with the presence of > the vector callback. > > The virtual interrupt controller on ARM has the concept of per-CPU > interrupt (PPI) which allow us to support per-VCPU event channel. > Therefore there is no need of vector callback for ARM. > > Xen is already using a free PPI to notify the guest VCPU of an event. > Furthermore, the xen code initialization in Linux (see > arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ. > > Introduce new helper xen_support_evtchn_rebind to allow architecture > decide whether rebind an event is support or not. It will always return > 1 on ARM and keep the same behavior on x86. > > This is also allow us to drop the usage of xen_have_vector_callback > entirely in the ARM code. This did not apply cleanly. Please always base patches on Linus's master branch. This also breaks the x86 build. /local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h: In function ?xen_support_evtchn_rebind?: /local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h:29:85: error: ?xen_have_vector_callback? undeclared (first use in this function) return (!xen_hvm_domain() || xen_have_vector_callback); > --- a/arch/arm/include/asm/xen/events.h > +++ b/arch/arm/include/asm/xen/events.h > @@ -20,4 +20,10 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) > atomic64_t, \ > counter), (val)) > > +/* Rebind event channel is supported by default */ > +static inline bool xen_support_evtchn_rebind(void) > +{ > + return 1; This should be true (similarly for arm64). David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/