Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753964AbdHUOqK (ORCPT ); Mon, 21 Aug 2017 10:46:10 -0400 Received: from mx2.suse.de ([195.135.220.15]:52223 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753245AbdHUOqI (ORCPT ); Mon, 21 Aug 2017 10:46:08 -0400 Subject: Re: [PATCH v06 27/36] uapi xen/gntdev.h: include xen/privcmd.h and define grant_ref_t To: Boris Ostrovsky , Mikko Rapeli , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Cc: xen-devel@lists.xenproject.org, Andrew Morton , Masahiro Yamada References: <20170806164428.2273-1-mikko.rapeli@iki.fi> <20170806164428.2273-28-mikko.rapeli@iki.fi> From: Juergen Gross Message-ID: Date: Mon, 21 Aug 2017 16:46:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2971 Lines: 87 On 21/08/17 16:31, Boris Ostrovsky wrote: > On 08/21/2017 09:33 AM, Juergen Gross wrote: >> On 06/08/17 18:44, Mikko Rapeli wrote: >>> Both are needed to compile in userspace. Fixes these >>> userspace compile errors: >>> >>> xen/gntdev.h:151:4: error: unknown type name ‘grant_ref_t’ >>> grant_ref_t ref; >>> ^ >>> xen/gntdev.h:153:4: error: unknown type name ‘domid_t’ >>> domid_t domid; >>> ^ >>> >>> Signed-off-by: Mikko Rapeli >>> Cc: Boris Ostrovsky >>> Cc: Juergen Gross >>> Cc: xen-devel@lists.xenproject.org >>> --- >>> include/uapi/xen/gntdev.h | 6 ++++++ >>> include/xen/interface/grant_table.h | 6 +----- >>> 2 files changed, 7 insertions(+), 5 deletions(-) >>> >>> diff --git a/include/uapi/xen/gntdev.h b/include/uapi/xen/gntdev.h >>> index d0661977667e..f208706b07c9 100644 >>> --- a/include/uapi/xen/gntdev.h >>> +++ b/include/uapi/xen/gntdev.h >>> @@ -34,6 +34,12 @@ >>> #define __LINUX_PUBLIC_GNTDEV_H__ >>> >>> #include >>> +#include >>> + >>> +/* >>> + * Reference to a grant entry in a specified domain's grant table. >>> + */ >>> +typedef __u32 grant_ref_t; >>> >>> struct ioctl_gntdev_grant_ref { >>> /* The domain ID of the grant to be mapped. */ >>> diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h >>> index 7fb7112d667c..29b3724aec2c 100644 >>> --- a/include/xen/interface/grant_table.h >>> +++ b/include/xen/interface/grant_table.h >>> @@ -29,6 +29,7 @@ >>> #define __XEN_PUBLIC_GRANT_TABLE_H__ >>> >>> #include >>> +#include /* for grant_ref_t */ >> Hmm, I really don't like this. We import the Xen headers from the Xen >> source repository. The Xen specific types shouldn't be taken from >> non-Xen headers. >> >>> >>> /*********************************** >>> * GRANT TABLE REPRESENTATION >>> @@ -85,11 +86,6 @@ >>> */ >>> >>> /* >>> - * Reference to a grant entry in a specified domain's grant table. >>> - */ >>> -typedef uint32_t grant_ref_t; >>> - >>> -/* >>> * A grant table comprises a packed array of grant entries in one or more >>> * page frames shared between Xen and a guest. >>> * [XEN]: This field is written by Xen and read by the sharing guest. >>> >> I'd rather use __u32 instead of grant_ref_t in the uapi headers. >> >> Boris, what do you think? > > I agree that including a non-Xen file into include/xen/interface is not > especially desirable. > > Can we ifdef __KERNEL__grant_ref_t usage in uapi header, with else > clause using __u32? And maybe stick BUILD_BUG_ON somewhere to check that > sizes are still the same ? I'd rather use __u32 unconditionally and have the BUILD_BUG_ON in the grant or privcmd driver. Otherwise we'd depend on the sequence of #includes (what happens if a driver includes the uapi header before xen/interface/xen.h?) Juergen