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Commit e4184aaf authored by Daniel De Graaf's avatar Daniel De Graaf Committed by Konrad Rzeszutek Wilk
Browse files

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: default avatarDaniel De Graaf <dgdegra@tycho.nsa.gov>
Reviewed-by: default avatarIan Campbell <Ian.Campbell@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 77447991

drivers/xen/xenbus/xenbus_probe.c

+53 −48
Original line number Diff line number Diff line
@@ -696,27 +696,19 @@ 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;



	DPRINTK("");



	err = -ENODEV;

	if (!xen_domain())

		return err;



	/*

	 * Domain0 doesn't have a store_evtchn or store_mfn yet.

	 */

	if (xen_initial_domain()) {

	struct evtchn_alloc_unbound alloc_unbound;



	/* Allocate Xenstore page */

	page = get_zeroed_page(GFP_KERNEL);

	if (!page)

			goto out_error;

		goto out_err;



	xen_store_mfn = xen_start_info->store_mfn =

		pfn_to_mfn(virt_to_phys((void *)page) >>
@@ -729,14 +721,27 @@ static int __init xenbus_init(void) 
	err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,

					  &alloc_unbound);

	if (err == -ENOSYS)

			goto out_error;

		goto out_err;



	BUG_ON(err);

	xen_store_evtchn = xen_start_info->store_evtchn =

		alloc_unbound.port;



		xen_store_interface = mfn_to_virt(xen_store_mfn);

	} else {

	return 0;



 out_err:

	if (page != 0)

		free_page(page);

	return err;

}



static int __init xenbus_init(void)

{

	int err = 0;



	if (!xen_domain())

		return -ENODEV;



	if (xen_hvm_domain()) {

		uint64_t v = 0;

		err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
@@ -751,9 +756,14 @@ static int __init xenbus_init(void) 
	} 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);

		if (xen_store_evtchn)

			xenstored_ready = 1;

		else {

			err = xenstored_local_init();

			if (err)

				goto out_error;

		}

		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);



	return err;

}