diff options
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe.c | 91 |
1 files changed, 71 insertions, 20 deletions
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index fe360c33ce71..d367f2bd2b93 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -65,6 +65,7 @@ #include "xenbus.h" +static int xs_init_irq; int xen_store_evtchn; EXPORT_SYMBOL_GPL(xen_store_evtchn); @@ -750,6 +751,20 @@ static void xenbus_probe(void) { xenstored_ready = 1; + if (!xen_store_interface) { + xen_store_interface = xen_remap(xen_store_gfn << XEN_PAGE_SHIFT, + XEN_PAGE_SIZE); + /* + * Now it is safe to free the IRQ used for xenstore late + * initialization. No need to unbind: it is about to be + * bound again from xb_init_comms. Note that calling + * unbind_from_irqhandler now would result in xen_evtchn_close() + * being called and the event channel not being enabled again + * afterwards, resulting in missed event notifications. + */ + free_irq(xs_init_irq, &xb_waitq); + } + /* * In the HVM case, xenbus_init() deferred its call to * xs_init() in case callbacks were not operational yet. @@ -798,20 +813,22 @@ static int __init xenbus_probe_initcall(void) { /* * Probe XenBus here in the XS_PV case, and also XS_HVM unless we - * need to wait for the platform PCI device to come up. + * need to wait for the platform PCI device to come up or + * xen_store_interface is not ready. */ if (xen_store_domain_type == XS_PV || (xen_store_domain_type == XS_HVM && - !xs_hvm_defer_init_for_callback())) + !xs_hvm_defer_init_for_callback() && + xen_store_interface != NULL)) xenbus_probe(); /* - * For XS_LOCAL, spawn a thread which will wait for xenstored - * or a xenstore-stubdom to be started, then probe. It will be - * triggered when communication starts happening, by waiting - * on xb_waitq. + * For XS_LOCAL or when xen_store_interface is not ready, spawn a + * thread which will wait for xenstored or a xenstore-stubdom to be + * started, then probe. It will be triggered when communication + * starts happening, by waiting on xb_waitq. */ - if (xen_store_domain_type == XS_LOCAL) { + if (xen_store_domain_type == XS_LOCAL || xen_store_interface == NULL) { struct task_struct *probe_task; probe_task = kthread_run(xenbus_probe_thread, NULL, @@ -907,10 +924,25 @@ static struct notifier_block xenbus_resume_nb = { .notifier_call = xenbus_resume_cb, }; +static irqreturn_t xenbus_late_init(int irq, void *unused) +{ + int err; + uint64_t v = 0; + + err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v); + if (err || !v || !~v) + return IRQ_HANDLED; + xen_store_gfn = (unsigned long)v; + + wake_up(&xb_waitq); + return IRQ_HANDLED; +} + static int __init xenbus_init(void) { int err; uint64_t v = 0; + bool wait = false; xen_store_domain_type = XS_UNKNOWN; if (!xen_domain()) @@ -957,25 +989,44 @@ static int __init xenbus_init(void) * been properly initialized. Instead of attempting to map a * wrong guest physical address return error. * - * Also recognize all bits set as an invalid value. + * Also recognize all bits set as an invalid/uninitialized value. */ - if (!v || !~v) { + if (!v) { err = -ENOENT; goto out_error; } - /* Avoid truncation on 32-bit. */ + if (v == ~0ULL) { + wait = true; + } else { + /* Avoid truncation on 32-bit. */ #if BITS_PER_LONG == 32 - if (v > ULONG_MAX) { - pr_err("%s: cannot handle HVM_PARAM_STORE_PFN=%llx > ULONG_MAX\n", - __func__, v); - err = -EINVAL; - goto out_error; - } + if (v > ULONG_MAX) { + pr_err("%s: cannot handle HVM_PARAM_STORE_PFN=%llx > ULONG_MAX\n", + __func__, v); + err = -EINVAL; + goto out_error; + } #endif - xen_store_gfn = (unsigned long)v; - xen_store_interface = - xen_remap(xen_store_gfn << XEN_PAGE_SHIFT, - XEN_PAGE_SIZE); + xen_store_gfn = (unsigned long)v; + xen_store_interface = + xen_remap(xen_store_gfn << XEN_PAGE_SHIFT, + XEN_PAGE_SIZE); + if (xen_store_interface->connection != XENSTORE_CONNECTED) + wait = true; + } + if (wait) { + err = bind_evtchn_to_irqhandler(xen_store_evtchn, + xenbus_late_init, + 0, "xenstore_late_init", + &xb_waitq); + if (err < 0) { + pr_err("xenstore_late_init couldn't bind irq err=%d\n", + err); + return err; + } + + xs_init_irq = err; + } break; default: pr_warn("Xenstore state unknown\n"); |