From e4184aaf3b2c4f2b69306f6cfc4bab8733c6c5f1 Mon Sep 17 00:00:00 2001 From: Daniel De Graaf Date: Thu, 13 Oct 2011 16:07:08 -0400 Subject: [PATCH] xenbus: don't rely on xen_initial_domain to detect local xenstore The xenstore daemon does not have to run in the xen initial domain; however, Linux currently uses xen_initial_domain to test if a loopback event channel should be used instead of the event channel provided in Xen's start_info structure. Instead, if the event channel passed in the start_info structure is not valid, assume that this domain will run xenstored locally and set up the event channel. Signed-off-by: Daniel De Graaf Reviewed-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/xenbus/xenbus_probe.c | 101 ++++++++++++++++++++------------------ 1 file changed, 53 insertions(+), 48 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index d5347fe..13b0f05 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -696,64 +696,74 @@ static int __init xenbus_probe_initcall(void) device_initcall(xenbus_probe_initcall); -static int __init xenbus_init(void) +/* Set up event channel for xenstored which is run as a local process + * (this is normally used only in dom0) + */ +static int __init xenstored_local_init(void) { int err = 0; unsigned long page = 0; + struct evtchn_alloc_unbound alloc_unbound; - DPRINTK(""); + /* Allocate Xenstore page */ + page = get_zeroed_page(GFP_KERNEL); + if (!page) + goto out_err; - err = -ENODEV; - if (!xen_domain()) - return err; + xen_store_mfn = xen_start_info->store_mfn = + pfn_to_mfn(virt_to_phys((void *)page) >> + PAGE_SHIFT); - /* - * Domain0 doesn't have a store_evtchn or store_mfn yet. - */ - if (xen_initial_domain()) { - struct evtchn_alloc_unbound alloc_unbound; + /* Next allocate a local port which xenstored can bind to */ + alloc_unbound.dom = DOMID_SELF; + alloc_unbound.remote_dom = DOMID_SELF; - /* Allocate Xenstore page */ - page = get_zeroed_page(GFP_KERNEL); - if (!page) - goto out_error; + err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, + &alloc_unbound); + if (err == -ENOSYS) + goto out_err; - xen_store_mfn = xen_start_info->store_mfn = - pfn_to_mfn(virt_to_phys((void *)page) >> - PAGE_SHIFT); + BUG_ON(err); + xen_store_evtchn = xen_start_info->store_evtchn = + alloc_unbound.port; - /* Next allocate a local port which xenstored can bind to */ - alloc_unbound.dom = DOMID_SELF; - alloc_unbound.remote_dom = DOMID_SELF; + return 0; - err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, - &alloc_unbound); - if (err == -ENOSYS) - goto out_error; + out_err: + if (page != 0) + free_page(page); + return err; +} - BUG_ON(err); - xen_store_evtchn = xen_start_info->store_evtchn = - alloc_unbound.port; +static int __init xenbus_init(void) +{ + int err = 0; - xen_store_interface = mfn_to_virt(xen_store_mfn); + if (!xen_domain()) + return -ENODEV; + + 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 { - 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); + xen_store_evtchn = xen_start_info->store_evtchn; + xen_store_mfn = xen_start_info->store_mfn; + if (xen_store_evtchn) + xenstored_ready = 1; + else { + err = xenstored_local_init(); 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; - xen_store_interface = mfn_to_virt(xen_store_mfn); - xenstored_ready = 1; } + xen_store_interface = mfn_to_virt(xen_store_mfn); } /* Initialize the interface to xenstore. */ @@ -772,12 +782,7 @@ static int __init xenbus_init(void) proc_mkdir("xen", NULL); #endif - return 0; - - out_error: - if (page != 0) - free_page(page); - + out_error: return err; } -- 2.7.4