From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54428) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UgihY-0007LI-Td for qemu-devel@nongnu.org; Sun, 26 May 2013 17:42:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UgihS-0002yG-0U for qemu-devel@nongnu.org; Sun, 26 May 2013 17:42:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17807) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UgihR-0002y7-NL for qemu-devel@nongnu.org; Sun, 26 May 2013 17:41:57 -0400 Date: Mon, 27 May 2013 00:42:13 +0300 From: "Michael S. Tsirkin" Message-ID: <20130526214213.GB4828@redhat.com> References: <20130526175110.GA3115@redhat.com> <20130526181017.GB3115@redhat.com> <51A253C6.7060303@redhat.com> <20130526183747.GB3427@redhat.com> <51A25A2D.8030700@redhat.com> <20130526200251.GA4305@redhat.com> <51A26E95.5000207@redhat.com> <878v314gb2.fsf@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <878v314gb2.fsf@codemonkey.ws> Subject: Re: [Qemu-devel] [PATCH v2 00/11] qemu: use virtio linux headers in portable code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Paolo Bonzini , Rusty Russell , virtualization , qemu-devel@nongnu.org, Peter Maydell On Sun, May 26, 2013 at 03:49:53PM -0500, Anthony Liguori wrote: > Paolo Bonzini writes: > > > Il 26/05/2013 22:02, Michael S. Tsirkin ha scritto: > >> > My fault. I should have looked at linux/types.h (actually asm-generic/). > >> > >> Not really, __uX appear in the headers that were posted. > > Which is a problem because this is a reserved namespace in C99. > > >> What I'm saying is - a chance of a conflict is very remote, > >> if it happens it's a build failure so easy to debug. > > > > I'm sure that others will complain, :) but you can go ahead. > > I think we should clean up the virtio headers in the kernel first. > Seems like a good thing to do given the standardization effort too. > There are lots of headers in uapi that use the C99 int types I found 4: $ grep -l uint include/uapi/linux/*h include/uapi/linux/dm-log-userspace.h include/uapi/linux/fuse.h include/uapi/linux/jffs2.h include/uapi/linux/pps.h include/uapi/linux/rds.h include/uapi/linux/sctp.h That's not really lots. > so there > doesn't seem to be a reason they couldn't be used in virtio. fuse.h > even has a: > > #ifdef __KERNEL__ > #include > #else > #include > #endif > > Which seems like a reasonable thing to do. In kernel, we really want to use things like endian-ness checks (and, we really should have them in userspace too!). So we want __le32 and other kernel goodies like that. stdint.h won't cut it. > The only other kernel dependency is linux/if_ether.h to define > ETH_ALEN. But it seems completely reasonable to define a > VIRTIO_NET_MAC_ALEN or something like that. Ugh. Not really reasonable IMO. We also use ETH_P_IP in code, would like to get rid of redefining that too. But we can have our own linux/if_ether.h for non-linux hosts, just with a couple of macros like that, it's not a big deal. > This would make the virtio headers completely stand alone and includable > in userspace (without violating C99). > > Perhaps it's even worth moving the headers from uapi/linux to > uapi/virtio. Rusty, what do you think? > > Regards, > > Anhtony Liguori > > > > > Paolo