From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 22845EA4FC2 for ; Mon, 23 Feb 2026 14:04:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D20D510E432; Mon, 23 Feb 2026 14:04:09 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="PqxGeH35"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 834A610E42B for ; Mon, 23 Feb 2026 14:04:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1771855440; x=1803391440; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TOXZhx8tvOHkbQkOIxLjWcu/kjXOSY4YGQ40ylbu5Uc=; b=PqxGeH35wn5MN4R55nPhNQD3lwoBIwE6zllO7KjuA60rt1JB4UrVTrqw mO9jnYLS1yzRAGfOs1rQo3Z3SinNbCdEXHpiP/TV4PDo7UXWmNzs/t8io ijGBDco/G5Zpgl3xNE+mBalr2kWX9NVopu3Qjg8THNn2H4JC7m4OEPjrJ WnMmecVE9Mn7GUWsDDBRgH5pidBsTaU4ZT1fQXihCLdP8orrWsi6MChz2 VB+3Afq4LvsDM+1XWP7bs3bzqUYK6C49DOHT88uq2q0cZSZP5KqxQAr0f qOM8u/iBKTQgPmcODkmmjodfotMw9NkmPMO5hEFzzKcsyzbbmvhahaGpu g==; X-CSE-ConnectionGUID: JGJ9XYIfSjuFxIUUIzBCUA== X-CSE-MsgGUID: OV+mVqUKTq6CjEVs5gl8fg== X-IronPort-AV: E=McAfee;i="6800,10657,11709"; a="76460849" X-IronPort-AV: E=Sophos;i="6.21,306,1763452800"; d="scan'208";a="76460849" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2026 06:03:51 -0800 X-CSE-ConnectionGUID: U7DYQK0jSRut7jN0eRPPwA== X-CSE-MsgGUID: p+VOYQ2fSdClIaaK2a4H7A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,306,1763452800"; d="scan'208";a="214656276" Received: from ettammin-mobl3.ger.corp.intel.com (HELO mkuoppal-desk.intel.com) ([10.245.246.3]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2026 06:03:47 -0800 From: Mika Kuoppala To: intel-xe@lists.freedesktop.org Cc: simona.vetter@ffwll.ch, matthew.brost@intel.com, christian.koenig@amd.com, thomas.hellstrom@linux.intel.com, joonas.lahtinen@linux.intel.com, christoph.manszewski@intel.com, rodrigo.vivi@intel.com, andrzej.hajda@intel.com, matthew.auld@intel.com, maciej.patelczyk@intel.com, gwan-gyeong.mun@intel.com, Mika Kuoppala , Dominik Grzegorzek Subject: [PATCH 04/22] drm/xe/eudebug: Introduce discovery for resources Date: Mon, 23 Feb 2026 16:02:59 +0200 Message-ID: <20260223140318.1822138-5-mika.kuoppala@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260223140318.1822138-1-mika.kuoppala@linux.intel.com> References: <20260223140318.1822138-1-mika.kuoppala@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" A debugger connection can occur after a client has created and destroyed an arbitrary number of resources. To support this, we need to relay all currently existing resources to the debugger. The client is held on selected ioctls until this discovery process, executed by a workqueue, is complete. This patch is based on discovery work by Maciej Patelczyk for the i915 driver. v2: - use rw_semaphore to block DRM ioctls during discovery (Matthew) - only lock according to ioctl at play (Dominik) v4: - s/discovery_lock/ioctl_lock - change lock to be per xe_file as is connections Cc: Matthew Brost Cc: Dominik Grzegorzek Co-developed-by: Maciej Patelczyk Signed-off-by: Maciej Patelczyk Signed-off-by: Mika Kuoppala Acked-by: Matthew Brost #locking --- drivers/gpu/drm/xe/xe_device.c | 13 +++- drivers/gpu/drm/xe/xe_device.h | 42 +++++++++++ drivers/gpu/drm/xe/xe_device_types.h | 6 ++ drivers/gpu/drm/xe/xe_eudebug.c | 100 +++++++++++++++++++++++++- drivers/gpu/drm/xe/xe_eudebug_types.h | 7 ++ 5 files changed, 164 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c index 0e7b978d7efb..39a70aaaa253 100644 --- a/drivers/gpu/drm/xe/xe_device.c +++ b/drivers/gpu/drm/xe/xe_device.c @@ -111,6 +111,7 @@ static int xe_file_open(struct drm_device *dev, struct drm_file *file) #if IS_ENABLED(CONFIG_DRM_XE_EUDEBUG) mutex_init(&xef->eudebug.lock); INIT_LIST_HEAD(&xef->eudebug.target_link); + init_rwsem(&xef->eudebug.ioctl_lock); #endif file->driver_priv = xef; @@ -236,8 +237,12 @@ static long xe_drm_ioctl(struct file *file, unsigned int cmd, unsigned long arg) ACQUIRE(xe_pm_runtime_ioctl, pm)(xe); ret = ACQUIRE_ERR(xe_pm_runtime_ioctl, &pm); - if (ret >= 0) + if (ret >= 0) { + bool lock = xe_eudebug_discovery_lock(file, cmd); ret = drm_ioctl(file, cmd, arg); + if (lock) + xe_eudebug_discovery_unlock(file, cmd); + } return ret; } @@ -254,8 +259,12 @@ static long xe_drm_compat_ioctl(struct file *file, unsigned int cmd, unsigned lo ACQUIRE(xe_pm_runtime_ioctl, pm)(xe); ret = ACQUIRE_ERR(xe_pm_runtime_ioctl, &pm); - if (ret >= 0) + if (ret >= 0) { + bool lock = xe_eudebug_discovery_lock(file, cmd); ret = drm_compat_ioctl(file, cmd, arg); + if (lock) + xe_eudebug_discovery_unlock(file, cmd); + } return ret; } diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h index 39464650533b..79fbaf01dad7 100644 --- a/drivers/gpu/drm/xe/xe_device.h +++ b/drivers/gpu/drm/xe/xe_device.h @@ -7,6 +7,7 @@ #define _XE_DEVICE_H_ #include +#include #include "xe_device_types.h" #include "xe_gt_types.h" @@ -220,4 +221,45 @@ struct xe_vm *xe_device_asid_to_vm(struct xe_device *xe, u32 asid); #define LNL_FLUSH_WORK(wrk__) \ flush_work(wrk__) +#if IS_ENABLED(CONFIG_DRM_XE_EUDEBUG) +static inline int xe_eudebug_needs_ioctl_lock(const unsigned int cmd) +{ + const unsigned int xe_cmd = DRM_IOCTL_NR(cmd) - DRM_COMMAND_BASE; + + switch (xe_cmd) { + case DRM_XE_VM_CREATE: + case DRM_XE_VM_DESTROY: + case DRM_XE_VM_BIND: + case DRM_XE_EXEC_QUEUE_CREATE: + case DRM_XE_EXEC_QUEUE_DESTROY: + return 1; + } + + return 0; +} + +static inline bool xe_eudebug_discovery_lock(struct file *file, unsigned int cmd) +{ + struct drm_file *file_priv = file->private_data; + struct xe_file *xef = file_priv->driver_priv; + + if (!xe_eudebug_needs_ioctl_lock(cmd)) + return false; + + down_read(&xef->eudebug.ioctl_lock); + return true; +} + +static inline void xe_eudebug_discovery_unlock(struct file *file, unsigned int cmd) +{ + struct drm_file *file_priv = file->private_data; + struct xe_file *xef = file_priv->driver_priv; + + up_read(&xef->eudebug.ioctl_lock); +} +#else +static inline bool xe_eudebug_discovery_lock(struct file *file, unsigned int cmd) { return false; } +static inline void xe_eudebug_discovery_unlock(struct file *file, unsigned int cmd) { } +#endif /* CONFIG_DRM_XE_EUDEBUG */ + #endif diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h index 1a2beffa9498..21e749c6a635 100644 --- a/drivers/gpu/drm/xe/xe_device_types.h +++ b/drivers/gpu/drm/xe/xe_device_types.h @@ -582,6 +582,9 @@ struct xe_device { /** @eudebug.lock: protects state and targets */ struct mutex lock; + + /** @wq: used for client discovery */ + struct workqueue_struct *wq; } eudebug; #endif }; @@ -657,6 +660,9 @@ struct xe_file { /** @target_link: link into xe_device.eudebug.targets */ struct list_head target_link; + + /** @eudebug.ioctl_lock syncing ioctl access */ + struct rw_semaphore ioctl_lock; } eudebug; #endif }; diff --git a/drivers/gpu/drm/xe/xe_eudebug.c b/drivers/gpu/drm/xe/xe_eudebug.c index fa81b7a314f6..48f1e218aa63 100644 --- a/drivers/gpu/drm/xe/xe_eudebug.c +++ b/drivers/gpu/drm/xe/xe_eudebug.c @@ -35,6 +35,10 @@ * :ref:`File Descriptor Acquisition Methods ` for * details on how to obtain the target's fd. * + * After a successful connection, all existing resources that the target Xe DRM + * client already has are sent as events, as if they had been + * created right after the connection. This is referred to as discovery. + * */ /** @@ -242,6 +246,8 @@ static void xe_eudebug_free(struct kref *ref) struct xe_eudebug *d = container_of(ref, typeof(*d), ref); struct drm_xe_eudebug_event *event; + WARN_ON(work_pending(&d->discovery_work)); + xe_assert(d->xe, xe_eudebug_detached(d)); while (kfifo_get(&d->events.fifo, &event)) @@ -303,6 +309,8 @@ static bool xe_eudebug_detach(struct xe_device *xe, } mutex_unlock(&d->target.lock); + flush_work(&d->discovery_work); + if (!target) return false; @@ -334,7 +342,7 @@ static int _xe_eudebug_disconnect(struct xe_eudebug *d, }) static struct xe_eudebug * -xe_eudebug_get(struct xe_file *xef) +xe_eudebug_get_nolock(struct xe_file *xef) { struct xe_eudebug *d; @@ -347,7 +355,8 @@ xe_eudebug_get(struct xe_file *xef) if (!d) return NULL; - if (xe_eudebug_detached(d)) { + if (xe_eudebug_detached(d) || + !completion_done(&d->discovery)) { xe_eudebug_put(d); return NULL; } @@ -355,6 +364,14 @@ xe_eudebug_get(struct xe_file *xef) return d; } +static struct xe_eudebug * +xe_eudebug_get(struct xe_file *xef) +{ + lockdep_assert_held(&xef->eudebug.ioctl_lock); + + return xe_eudebug_get_nolock(xef); +} + static int xe_eudebug_queue_event(struct xe_eudebug *d, struct drm_xe_eudebug_event *event) { @@ -578,6 +595,8 @@ static int xe_eudebug_remove_handle(struct xe_eudebug *d, int type, void *p, { int ret; + XE_WARN_ON(!completion_done(&d->discovery)); + ret = _xe_eudebug_remove_handle(d, type, p, seqno); eu_dbg(d, "handle type %d handle %p removed: %d\n", type, p, ret); @@ -709,6 +728,66 @@ void xe_eudebug_vm_destroy(struct xe_file *xef, struct xe_vm *vm) xe_eudebug_event_put(d, vm_destroy_event(d, xef, vm)); } +static struct xe_file *xe_eudebug_target_get(struct xe_eudebug *d) +{ + struct xe_file *xef = NULL; + + mutex_lock(&d->target.lock); + if (d->target.xef) + xef = xe_file_get(d->target.xef); + mutex_unlock(&d->target.lock); + + return xef; +} + +static void discover_client(struct xe_eudebug *d) +{ + struct xe_file *xef; + struct xe_vm *vm; + unsigned long i; + unsigned int vm_count = 0; + int err = 0; + + xef = xe_eudebug_target_get(d); + if (!xef) + return; + + down_write(&xef->eudebug.ioctl_lock); + + eu_dbg(d, "Discovery start for %lld", d->session); + + xa_for_each(&xef->vm.xa, i, vm) { + err = vm_create_event(d, xef, vm); + if (err) + break; + vm_count++; + } + + complete_all(&d->discovery); + + eu_dbg(d, "Discovery end for %lld: %d", d->session, err); + + up_write(&xef->eudebug.ioctl_lock); + + if (vm_count) + eu_dbg(d, "Discovery found %u vms", vm_count); + + xe_file_put(xef); +} + +static void discovery_work_fn(struct work_struct *work) +{ + struct xe_eudebug *d = container_of(work, typeof(*d), + discovery_work); + + if (xe_eudebug_detached(d)) + complete_all(&d->discovery); + else + discover_client(d); + + xe_eudebug_put(d); +} + static int add_debugger(struct xe_device *xe, struct xe_eudebug *d, struct drm_file *target) { @@ -919,6 +998,10 @@ static long xe_eudebug_ioctl(struct file *file, struct xe_eudebug * const d = file->private_data; long ret; + if (cmd != DRM_XE_EUDEBUG_IOCTL_READ_EVENT && + !completion_done(&d->discovery)) + return -EBUSY; + switch (cmd) { case DRM_XE_EUDEBUG_IOCTL_READ_EVENT: ret = xe_eudebug_read_event(d, arg, @@ -980,9 +1063,11 @@ xe_eudebug_connect(struct xe_device *xe, mutex_init(&d->target.lock); init_waitqueue_head(&d->events.write_done); init_waitqueue_head(&d->events.read_done); + init_completion(&d->discovery); spin_lock_init(&d->events.lock); INIT_KFIFO(d->events.fifo); + INIT_WORK(&d->discovery_work, discovery_work_fn); err = xe_eudebug_resources_init(d); if (XE_IOCTL_DBG(xe, err)) @@ -998,6 +1083,9 @@ xe_eudebug_connect(struct xe_device *xe, goto err_detach; } + kref_get(&d->ref); + queue_work(xe->eudebug.wq, &d->discovery_work); + eu_dbg(d, "connected session %lld", d->session); return fd; @@ -1089,6 +1177,7 @@ static void xe_eudebug_sysfs_fini(void *arg) void xe_eudebug_init(struct xe_device *xe) { struct drm_device *dev = &xe->drm; + struct workqueue_struct *wq; int err; INIT_LIST_HEAD(&xe->eudebug.targets); @@ -1099,6 +1188,13 @@ void xe_eudebug_init(struct xe_device *xe) if (err) goto out_err; + wq = drmm_alloc_ordered_workqueue(dev, "xe-eudebug", 0); + if (IS_ERR(wq)) { + err = PTR_ERR(wq); + goto out_err; + } + xe->eudebug.wq = wq; + err = sysfs_create_file(&dev->dev->kobj, &dev_attr_enable_eudebug.attr); if (err) diff --git a/drivers/gpu/drm/xe/xe_eudebug_types.h b/drivers/gpu/drm/xe/xe_eudebug_types.h index a73eb6c98b02..d7625e55d711 100644 --- a/drivers/gpu/drm/xe/xe_eudebug_types.h +++ b/drivers/gpu/drm/xe/xe_eudebug_types.h @@ -17,6 +17,7 @@ struct xe_device; struct task_struct; +struct workqueue_struct; /** * enum xe_eudebug_state - eudebug capability state @@ -96,6 +97,12 @@ struct xe_eudebug { /** @session: session number for this connection (for logs) */ u64 session; + /** @discovery: completion to wait for discovery */ + struct completion discovery; + + /** @discovery_work: worker to discover resources for target_task */ + struct work_struct discovery_work; + /** @events: kfifo queue of to-be-delivered events */ struct { /** @lock: guards access to fifo */ -- 2.43.0