From e08dd1ee49838750a514e83c0aa60cd12ba6ecbb Mon Sep 17 00:00:00 2001 From: Jason Andryuk Date: Wed, 19 Nov 2025 17:47:29 -0500 Subject: [PATCH] xenbus: Use .freeze/.thaw to handle xenbus devices The goal is to fix s2idle and S3 for Xen PV devices. A domain resuming from s3 or s2idle disconnects its PV devices during resume. The backends are not expecting this and do not reconnect. b3e96c0c7562 ("xen: use freeze/restore/thaw PM events for suspend/ resume/chkpt") changed xen_suspend()/do_suspend() from PMSG_SUSPEND/PMSG_RESUME to PMSG_FREEZE/PMSG_THAW/PMSG_RESTORE, but the suspend/resume callbacks remained. .freeze/restore are used with hiberation where Linux restarts in a new place in the future. .suspend/resume are useful for runtime power management for the duration of a boot. The current behavior of the callbacks works for an xl save/restore or live migration where the domain is restored/migrated to a new location and connecting to a not-already-connected backend. Change xenbus_pm_ops to use .freeze/thaw/restore and drop the .suspend/resume hook. This matches the use in drivers/xen/manage.c for save/restore and live migration. With .suspend/resume empty, PV devices are left connected during s2idle and s3, so PV devices are not changed and work after resume. Signed-off-by: Jason Andryuk Acked-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <20251119224731.61497-2-jason.andryuk@amd.com> --- drivers/xen/xenbus/xenbus_probe_frontend.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c index 6d1819269cbe5..199917b6f77ca 100644 --- a/drivers/xen/xenbus/xenbus_probe_frontend.c +++ b/drivers/xen/xenbus/xenbus_probe_frontend.c @@ -148,11 +148,9 @@ static void xenbus_frontend_dev_shutdown(struct device *_dev) } static const struct dev_pm_ops xenbus_pm_ops = { - .suspend = xenbus_dev_suspend, - .resume = xenbus_frontend_dev_resume, .freeze = xenbus_dev_suspend, .thaw = xenbus_dev_cancel, - .restore = xenbus_dev_resume, + .restore = xenbus_frontend_dev_resume, }; static struct xen_bus_type xenbus_frontend = { -- 2.47.3