Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753655Ab0BILxF (ORCPT ); Tue, 9 Feb 2010 06:53:05 -0500 Received: from smtp.citrix.com ([66.165.176.89]:27767 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752602Ab0BILw7 (ORCPT ); Tue, 9 Feb 2010 06:52:59 -0500 X-IronPort-AV: E=Sophos;i="4.49,436,1262581200"; d="scan'208";a="7119844" Subject: Re: [PATCH 5/7] xen: Make event channel work with PV featured HVM From: Ian Campbell To: Sheng Yang CC: Jeremy Fitzhardinge , Keir Fraser , xen-devel , "linux-kernel@vger.kernel.org" In-Reply-To: <1265616354-7384-6-git-send-email-sheng@linux.intel.com> References: <1265616354-7384-1-git-send-email-sheng@linux.intel.com> <1265616354-7384-6-git-send-email-sheng@linux.intel.com> Content-Type: text/plain; charset="UTF-8" Organization: Citrix Systems, Inc. Date: Tue, 9 Feb 2010 11:52:56 +0000 Message-ID: <1265716376.24394.32669.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1176 Lines: 29 On Mon, 2010-02-08 at 08:05 +0000, Sheng Yang wrote: > + if (xen_hvm_pv_evtchn_enabled()) { > + if (enable_hvm_pv(HVM_PV_EVTCHN)) > + return -EINVAL; > +[...] > + callback_via = HVM_CALLBACK_VECTOR(X86_PLATFORM_IPI_VECTOR); > + set_callback_via(callback_via); > + > + x86_platform_ipi_callback = do_hvm_pv_evtchn_intr; Why this indirection via X86_PLATFORM_IPI_VECTOR? Apart from that why not use CALLBACKOP_register subop CALLBACKTYPE_event pointing to xen_hypervisor_callback the same as a full PV guest? This would remove all the evtchn related code from HVMOP_enable_pv which I think should be eventually unnecessary as an independent hypercall since all HVM guests should simply be PV capable by default -- the hypervisor only needs to track if the guest has made use of specific PV functionality, not the umbrella "is PV" state. Ian. -- 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/