From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757338Ab2HQRJV (ORCPT ); Fri, 17 Aug 2012 13:09:21 -0400 Received: from smtp.eu.citrix.com ([62.200.22.115]:37181 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754100Ab2HQRJK (ORCPT ); Fri, 17 Aug 2012 13:09:10 -0400 X-IronPort-AV: E=Sophos;i="4.77,785,1336348800"; d="scan'208";a="14064569" Date: Fri, 17 Aug 2012 18:08:51 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Konrad Rzeszutek Wilk CC: "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" Subject: Re: [Xen-devel] [PATCH 1/5] xen/swiotlb: Simplify the logic. In-Reply-To: <1345132488-27323-2-git-send-email-konrad.wilk@oracle.com> Message-ID: References: <1345132488-27323-1-git-send-email-konrad.wilk@oracle.com> <1345132488-27323-2-git-send-email-konrad.wilk@oracle.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 16 Aug 2012, Konrad Rzeszutek Wilk wrote: > Its pretty easy: > 1). We only check to see if we need Xen SWIOTLB for PV guests. > 2). If swiotlb=force or iommu=soft is set, then Xen SWIOTLB will > be enabled. > 3). If it is an initial domain, then Xen SWIOTLB will be enabled. > 4). Native SWIOTLB must be disabled for PV guests. > > Signed-off-by: Konrad Rzeszutek Wilk Acked-by: Stefano Stabellini > arch/x86/xen/pci-swiotlb-xen.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c > index 967633a..b6a5340 100644 > --- a/arch/x86/xen/pci-swiotlb-xen.c > +++ b/arch/x86/xen/pci-swiotlb-xen.c > @@ -34,19 +34,20 @@ static struct dma_map_ops xen_swiotlb_dma_ops = { > int __init pci_xen_swiotlb_detect(void) > { > > + if (!xen_pv_domain()) > + return 0; > + > /* If running as PV guest, either iommu=soft, or swiotlb=force will > * activate this IOMMU. If running as PV privileged, activate it > * irregardless. > */ > - if ((xen_initial_domain() || swiotlb || swiotlb_force) && > - (xen_pv_domain())) > + if ((xen_initial_domain() || swiotlb || swiotlb_force)) > xen_swiotlb = 1; > > /* If we are running under Xen, we MUST disable the native SWIOTLB. > * Don't worry about swiotlb_force flag activating the native, as > * the 'swiotlb' flag is the only one turning it on. */ > - if (xen_pv_domain()) > - swiotlb = 0; > + swiotlb = 0; > > return xen_swiotlb; > } > -- > 1.7.7.6 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel >