Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758925Ab2HHQwH (ORCPT ); Wed, 8 Aug 2012 12:52:07 -0400 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:37109 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758912Ab2HHQwE (ORCPT ); Wed, 8 Aug 2012 12:52:04 -0400 X-IronPort-AV: E=Sophos;i="4.77,733,1336348800"; d="scan'208";a="13914482" Date: Wed, 8 Aug 2012 17:51:39 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Daniel De Graaf CC: Konrad Rzeszutek Wilk , Stefano Stabellini , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , Ian Campbell , "Tim (Xen.org)" , "linux-arm-kernel@lists.infradead.org" , "linaro-dev@lists.linaro.org" , "catalin.marinas@arm.com" , "arnd@arndb.de" Subject: Re: [PATCH v2 10/23] xen/arm: compile and run xenbus In-Reply-To: <50216228.7010407@tycho.nsa.gov> Message-ID: References: <1344263246-28036-10-git-send-email-stefano.stabellini@eu.citrix.com> <20120807182157.GN15053@phenom.dumpdata.com> <50216228.7010407@tycho.nsa.gov> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4393 Lines: 132 On Tue, 7 Aug 2012, Daniel De Graaf wrote: > On 08/07/2012 02:21 PM, Konrad Rzeszutek Wilk wrote: > > On Mon, Aug 06, 2012 at 03:27:13PM +0100, Stefano Stabellini wrote: > >> bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not > >> an error. > >> > >> If Linux is running as an HVM domain and is running as Dom0, use > >> xenstored_local_init to initialize the xenstore page and event channel. > >> > >> Changes in v2: > >> > >> - refactor xenbus_init. > > > > Thank you. Lets also CC our friend at NSA who has been doing some work > > in that area. Daniel are you OK with this change - will it still make > > PV initial domain with with the MiniOS XenBus driver? > > > > Thanks. > > That case will work, but what this will break is launching the initial domain > with a Xenstore stub domain already running (see below). > > >> > >> Signed-off-by: Stefano Stabellini > >> --- > >> drivers/xen/xenbus/xenbus_comms.c | 2 +- > >> drivers/xen/xenbus/xenbus_probe.c | 62 +++++++++++++++++++++++++----------- > >> drivers/xen/xenbus/xenbus_xs.c | 1 + > >> 3 files changed, 45 insertions(+), 20 deletions(-) > >> > >> diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c > >> index 52fe7ad..c5aa55c 100644 > >> --- a/drivers/xen/xenbus/xenbus_comms.c > >> +++ b/drivers/xen/xenbus/xenbus_comms.c > >> @@ -224,7 +224,7 @@ int xb_init_comms(void) > >> int err; > >> err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting, > >> 0, "xenbus", &xb_waitq); > >> - if (err <= 0) { > >> + if (err < 0) { > >> printk(KERN_ERR "XENBUS request irq failed %i\n", err); > >> return err; > >> } > > > >> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c > >> index b793723..a67ccc0 100644 > >> --- a/drivers/xen/xenbus/xenbus_probe.c > >> +++ b/drivers/xen/xenbus/xenbus_probe.c > >> @@ -719,37 +719,61 @@ static int __init xenstored_local_init(void) > >> return err; > >> } > >> > >> +enum xenstore_init { > >> + UNKNOWN, > >> + PV, > >> + HVM, > >> + LOCAL, > >> +}; > >> static int __init xenbus_init(void) > >> { > >> int err = 0; > >> + enum xenstore_init usage = UNKNOWN; > >> + uint64_t v = 0; > >> > >> if (!xen_domain()) > >> return -ENODEV; > >> > >> xenbus_ring_ops_init(); > >> > >> - if (xen_hvm_domain()) { > >> - uint64_t v = 0; > >> - err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v); > >> - if (err) > >> - goto out_error; > >> - xen_store_evtchn = (int)v; > >> - err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v); > >> - if (err) > >> - goto out_error; > >> - xen_store_mfn = (unsigned long)v; > >> - xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE); > >> - } else { > >> - xen_store_evtchn = xen_start_info->store_evtchn; > >> - xen_store_mfn = xen_start_info->store_mfn; > >> - if (xen_store_evtchn) > >> - xenstored_ready = 1; > >> - else { > >> + if (xen_pv_domain()) > >> + usage = PV; > >> + if (xen_hvm_domain()) > >> + usage = HVM; > > The above is correct for domUs, and is overridden for dom0s: > > >> + if (xen_hvm_domain() && xen_initial_domain()) > >> + usage = LOCAL; > >> + if (xen_pv_domain() && !xen_start_info->store_evtchn) > >> + usage = LOCAL; > > Instead of these checks, I think it should just be: > > if (!xen_start_info->store_evtchn) > usage = LOCAL; > > Any domain started after xenstore will have store_evtchn set, so if you don't > have this set, you are either going to be running xenstore locally, or will > use the ioctl to change it later (and so should still set up everything as if > it will be running locally). That would be wrong for an HVM dom0 domain (at least on ARM), because we don't have a start_info page at all. > >> + if (xen_pv_domain() && xen_start_info->store_evtchn) > >> + xenstored_ready = 1; > > This part can now just be moved unconditionally into case PV. What about: if (xen_pv_domain()) usage = PV; if (xen_hvm_domain()) usage = HVM; if (!xen_store_evtchn) usage = LOCAL; and moving xenstored_ready in case PV, like you suggested. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/