From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755299AbdABGNj (ORCPT ); Mon, 2 Jan 2017 01:13:39 -0500 Received: from mx2.suse.de ([195.135.220.15]:54116 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750808AbdABGNi (ORCPT ); Mon, 2 Jan 2017 01:13:38 -0500 Subject: Re: [PATCH V2] Xen: ARM: Zero reserved fields of xatp before making hypervisor call To: Jiandi An , boris.ostrovsky@oracle.com, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, sstabellini@kernel.org, julien.grall@arm.com References: <1482886052-30111-1-git-send-email-anjiandi@codeaurora.org> From: Juergen Gross Message-ID: Date: Mon, 2 Jan 2017 07:13:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <1482886052-30111-1-git-send-email-anjiandi@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/12/16 01:47, Jiandi An wrote: > Ensure all reserved fields of xatp are zero before making > hypervisor call to XEN in xen_map_device_mmio(). > xenmem_add_to_physmap_one() in XEN fails the mapping request if > extra.res reserved field in xatp is not zero for XENMAPSPACE_dev_mmio > request. > > Signed-off-by: Jiandi An > --- > Changed zeroing xatp to a static initialization > of .domid and .space for xatp. > > drivers/xen/arm-device.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/xen/arm-device.c b/drivers/xen/arm-device.c > index 778acf8..85dd20e 100644 > --- a/drivers/xen/arm-device.c > +++ b/drivers/xen/arm-device.c > @@ -58,9 +58,13 @@ static int xen_map_device_mmio(const struct resource *resources, > xen_pfn_t *gpfns; > xen_ulong_t *idxs; > int *errs; > - struct xen_add_to_physmap_range xatp; > > for (i = 0; i < count; i++) { > + struct xen_add_to_physmap_range xatp = { > + .domid = DOMID_SELF, > + .space = XENMAPSPACE_dev_mmio > + }; > + I still don't see the need to re-initialize the input parts of xatp on each loop iteration unless you can show the need for it (e.g. a buggy hypervisor version not conforming to the interface specification). OTOH I don't feel really strong about it and let Stefano being the maintainer for the ARM parts decide. Juergen > r = &resources[i]; > nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE); > if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0)) > @@ -87,9 +91,7 @@ static int xen_map_device_mmio(const struct resource *resources, > idxs[j] = XEN_PFN_DOWN(r->start) + j; > } > > - xatp.domid = DOMID_SELF; > xatp.size = nr; > - xatp.space = XENMAPSPACE_dev_mmio; > > set_xen_guest_handle(xatp.gpfns, gpfns); > set_xen_guest_handle(xatp.idxs, idxs); >