From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCHv1] xen-blkback: default to X86_32 ABI on x86 Date: Thu, 5 Feb 2015 14:44:50 -0500 Message-ID: <20150205194449.GH11646@x230.dumpdata.com> References: <1423156196-27117-1-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YJSME-0007gA-LK for xen-devel@lists.xenproject.org; Thu, 05 Feb 2015 19:44:58 +0000 Content-Disposition: inline In-Reply-To: <1423156196-27117-1-git-send-email-david.vrabel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: David Vrabel Cc: xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On Thu, Feb 05, 2015 at 05:09:56PM +0000, David Vrabel wrote: > Prior to the existance of 64-bit backends using the X86_64 ABI, > frontends used the X86_32 ABI. These old frontends do not specify the > ABI and when used with a 64-bit backend do not work. Whoa. How old are we talking? I had been using RHEL5 guests and those work OK (64bit dom0, 32-bit domU). > > On x86, default to the X86_32 ABI if one is not specified. Backends > on ARM continue to default to their NATIVE ABI. > > Signed-off-by: David Vrabel > --- > drivers/block/xen-blkback/common.h | 9 +++++++++ > drivers/block/xen-blkback/xenbus.c | 4 ++-- > 2 files changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h > index f65b807..78b0411 100644 > --- a/drivers/block/xen-blkback/common.h > +++ b/drivers/block/xen-blkback/common.h > @@ -214,6 +214,15 @@ enum blkif_protocol { > BLKIF_PROTOCOL_X86_64 = 3, > }; > > +/* > + * Default protocol if the frontend doesn't specify one. > + */ > +#ifdef CONFIG_X86 > +# define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_X86_32 > +#else > +# define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_NATIVE > +#endif > + > struct xen_vbd { > /* What the domain refers to this vbd as. */ > blkif_vdev_t handle; > diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c > index 630a489..e3afe97 100644 > --- a/drivers/block/xen-blkback/xenbus.c > +++ b/drivers/block/xen-blkback/xenbus.c > @@ -868,11 +868,11 @@ static int connect_ring(struct backend_info *be) > return err; > } > > - be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; > + be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; > err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", > "%63s", protocol, NULL); > if (err) > - strcpy(protocol, "unspecified, assuming native"); > + strcpy(protocol, "unspecified, assuming default"); > else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) > be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; > else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) > -- > 1.7.10.4 >