From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:35686 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753455Ab3LDEzz (ORCPT ); Tue, 3 Dec 2013 23:55:55 -0500 Message-ID: <529EB629.1020605@oracle.com> Date: Wed, 04 Dec 2013 12:57:13 +0800 From: DuanZhenzhong MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: Bjorn Helgaas , xen-devel@lists.xenproject.org, "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , Sucheta Chakraborty , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "x86@kernel.org" Subject: Re: [PATCH] PCI: Introduce two new MSI infrastructure calls for masking/unmasking. References: <1383772616-23060-1-git-send-email-konrad.wilk@oracle.com> <527C41E9.6040002@oracle.com> <20131108153507.GA24755@phenom.dumpdata.com> In-Reply-To: <20131108153507.GA24755@phenom.dumpdata.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: Konrad Rzeszutek Wilk wrote: > On Fri, Nov 08, 2013 at 09:44:09AM +0800, Zhenzhong Duan wrote: > >> On 2013-11-07 07:51, Bjorn Helgaas wrote: >> >>> [+cc Thomas, Ingo, Peter, x86 list] >>> >>> On Wed, Nov 6, 2013 at 2:16 PM, Konrad Rzeszutek Wilk >>> wrote: >>> >>>> Certain platforms do not allow writes in the MSI-X bars >>>> to setup or tear down vector values. To combat against >>>> the generic code trying to write to that and either silently >>>> being ignored or crashing due to the pagetables being marked r/o >>>> this patch introduces a platform over-write. >>>> >>>> Note that we keep two separate, non-weak, functions >>>> default_mask_msi_irqs() and default_mask_msix_irqs() for the >>>> behavior of the arch_mask_msi_irqs() and arch_mask_msix_irqs(), >>>> as the default behavior is needed by x86 PCI code. >>>> >>>> For Xen, which does not allow the guest to write to MSI-X >>>> tables - as the hypervisor is solely responsible for setting >>>> the vector values - we implement two nops. >>>> >>>> CC: Bjorn Helgaas >>>> CC: Sucheta Chakraborty >>>> CC: Zhenzhong Duan >>>> Signed-off-by: Konrad Rzeszutek Wilk >>>> >>> I think this is safe, and I'd like to squeeze it into the v3.13 merge >>> window next week, since it supersedes three patches Zhenzhong has been >>> trying to get in since July [1], and this patch is much simpler to >>> understand. >>> >> This patch could replace the first two. >> I think the third patch of mine is still needed as it does a >> different thing. >> It optimizes restore path in dom0. >> > > I tried to rebase it on top of this patch but it ended up that > you still need the two arguments (for restore_... operation). > > But perhaps there is a better way. If you can rebase on top > of this patch - and send it out - that would be great! > Ok, I'll send one rebased on your patch later. -- Regards zhenzhong -- Oracle Building, No.24 Building, Zhongguancun Software Park Haidian District, Beijing 100193, China