6.6-stable review patch. If anyone has any objections, please let me know.
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From: Henry Wang xin.wang2@amd.com
[ Upstream commit a3607581cd49c17128a486a526a36a97bafcb2bb ]
Currently, the late XenStore init protocol is only triggered properly for the case that HVM_PARAM_STORE_PFN is ~0ULL (invalid). For the case that XenStore interface is allocated but not ready (the connection status is not XENSTORE_CONNECTED), Linux should also wait until the XenStore is set up properly.
Introduce a macro to describe the XenStore interface is ready, use it in xenbus_probe_initcall() to select the code path of doing the late XenStore init protocol or not. Since now we have more than one condition for XenStore late init, rework the check in xenbus_probe() for the free_irq().
Take the opportunity to enhance the check of the allocated XenStore interface can be properly mapped, and return error early if the memremap() fails.
Fixes: 5b3353949e89 ("xen: add support for initializing xenstore later as HVM domain") Signed-off-by: Henry Wang xin.wang2@amd.com Signed-off-by: Michal Orzel michal.orzel@amd.com Reviewed-by: Stefano Stabellini sstabellini@kernel.org Link: https://lore.kernel.org/r/20240517011516.1451087-1-xin.wang2@amd.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/xen/xenbus/xenbus_probe.c | 36 ++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 13 deletions(-)
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 3205e5d724c8c..1a9ded0cddcb0 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -65,13 +65,17 @@ #include "xenbus.h"
-static int xs_init_irq; +static int xs_init_irq = -1; int xen_store_evtchn; EXPORT_SYMBOL_GPL(xen_store_evtchn);
struct xenstore_domain_interface *xen_store_interface; EXPORT_SYMBOL_GPL(xen_store_interface);
+#define XS_INTERFACE_READY \ + ((xen_store_interface != NULL) && \ + (xen_store_interface->connection == XENSTORE_CONNECTED)) + enum xenstore_init xen_store_domain_type; EXPORT_SYMBOL_GPL(xen_store_domain_type);
@@ -751,19 +755,19 @@ static void xenbus_probe(void) { xenstored_ready = 1;
- if (!xen_store_interface) { + if (!xen_store_interface) xen_store_interface = memremap(xen_store_gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE, MEMREMAP_WB); - /* - * 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. - */ + /* + * 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. + */ + if (xs_init_irq >= 0) free_irq(xs_init_irq, &xb_waitq); - }
/* * In the HVM case, xenbus_init() deferred its call to @@ -822,7 +826,7 @@ static int __init xenbus_probe_initcall(void) if (xen_store_domain_type == XS_PV || (xen_store_domain_type == XS_HVM && !xs_hvm_defer_init_for_callback() && - xen_store_interface != NULL)) + XS_INTERFACE_READY)) xenbus_probe();
/* @@ -831,7 +835,7 @@ static int __init xenbus_probe_initcall(void) * started, then probe. It will be triggered when communication * starts happening, by waiting on xb_waitq. */ - if (xen_store_domain_type == XS_LOCAL || xen_store_interface == NULL) { + if (xen_store_domain_type == XS_LOCAL || !XS_INTERFACE_READY) { struct task_struct *probe_task;
probe_task = kthread_run(xenbus_probe_thread, NULL, @@ -1014,6 +1018,12 @@ static int __init xenbus_init(void) xen_store_interface = memremap(xen_store_gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE, MEMREMAP_WB); + if (!xen_store_interface) { + pr_err("%s: cannot map HVM_PARAM_STORE_PFN=%llx\n", + __func__, v); + err = -EINVAL; + goto out_error; + } if (xen_store_interface->connection != XENSTORE_CONNECTED) wait = true; }