Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752070AbaABPcg (ORCPT ); Thu, 2 Jan 2014 10:32:36 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:44728 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751769AbaABPcf (ORCPT ); Thu, 2 Jan 2014 10:32:35 -0500 X-IronPort-AV: E=Sophos;i="4.95,591,1384300800"; d="scan'208";a="87065090" Message-ID: <52C58691.4040502@citrix.com> Date: Thu, 2 Jan 2014 15:32:33 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20121215 Iceowl/1.0b1 Icedove/3.0.11 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: , , , , Subject: Re: [PATCH v12 03/18] xen/pvh: Early bootup changes in PV code (v2). References: <1388550945-25499-1-git-send-email-konrad.wilk@oracle.com> <1388550945-25499-4-git-send-email-konrad.wilk@oracle.com> In-Reply-To: <1388550945-25499-4-git-send-email-konrad.wilk@oracle.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.76] X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1850 Lines: 61 On 01/01/14 04:35, Konrad Rzeszutek Wilk wrote: > From: Mukesh Rathor > > In the bootup code for PVH we can trap cpuid via vmexit, so don't > need to use emulated prefix call. We also check for vector callback > early on, as it is a required feature. PVH also runs at default kernel > IOPL. > > Finally, pure PV settings are moved to a separate function that are > only called for pure PV, ie, pv with pvmmu. They are also #ifdef > with CONFIG_XEN_PVMMU. [...] > @@ -331,12 +333,15 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, > break; > } > > - asm(XEN_EMULATE_PREFIX "cpuid" > - : "=a" (*ax), > - "=b" (*bx), > - "=c" (*cx), > - "=d" (*dx) > - : "0" (*ax), "2" (*cx)); > + if (xen_pvh_domain()) > + native_cpuid(ax, bx, cx, dx); > + else > + asm(XEN_EMULATE_PREFIX "cpuid" > + : "=a" (*ax), > + "=b" (*bx), > + "=c" (*cx), > + "=d" (*dx) > + : "0" (*ax), "2" (*cx)); For this one off cpuid call it seems preferrable to me to use the emulate prefix rather than diverge from PV. > @@ -1431,13 +1449,18 @@ asmlinkage void __init xen_start_kernel(void) > > xen_domain_type = XEN_PV_DOMAIN; > > + xen_setup_features(); > + xen_pvh_early_guest_init(); > xen_setup_machphys_mapping(); > > /* Install Xen paravirt ops */ > pv_info = xen_info; > pv_init_ops = xen_init_ops; > - pv_cpu_ops = xen_cpu_ops; > pv_apic_ops = xen_apic_ops; > + if (xen_pvh_domain()) > + pv_cpu_ops.cpuid = xen_cpuid; > + else > + pv_cpu_ops = xen_cpu_ops; If cpuid is trapped for PVH guests why does PVH need non-native cpuid op? 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/