From patchwork Thu Jul 11 21:52:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yichen Wang X-Patchwork-Id: 1959563 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=bytedance.com header.i=@bytedance.com header.a=rsa-sha256 header.s=google header.b=XCJ961Jx; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4WKpQl0R1Tz1xqc for ; Fri, 12 Jul 2024 07:54:06 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sS1is-0004Ek-4p; Thu, 11 Jul 2024 17:53:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sS1iq-0004Ag-WD for qemu-devel@nongnu.org; Thu, 11 Jul 2024 17:53:05 -0400 Received: from mail-ot1-x332.google.com ([2607:f8b0:4864:20::332]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sS1io-0005Zh-Mp for qemu-devel@nongnu.org; Thu, 11 Jul 2024 17:53:04 -0400 Received: by mail-ot1-x332.google.com with SMTP id 46e09a7af769-70368b53cc0so662244a34.1 for ; Thu, 11 Jul 2024 14:53:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1720734780; x=1721339580; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=lAClVOPjaYmAqeHOJnomznCPk2DbCytJlAbJtT0EBcU=; b=XCJ961Jxo5Q9tgv5PF01oPBtPyCBkYhApIjoMErVBb0r/d1WuHE7i/W0hXpK2/fWpp doFfqowKum1tDy6K71BwFVuEcwPi7lwXrZSciStwepMP7rv6VNz7YI5JaM0nEPNQ2ETL TMlADwDCiR/moYcexdg15GceN0QKeOWJlGNpUpnVRycJ5n4Eys4ILZK8n8JzXSkpl//X gYnYCRaWimN6w1LDixru6dxxoQ1qUvu1RcK3X+Wf20QNxEs+YgYN3NQFFeZVzpbBq59S Vt/sanZ1zUxa5EoR0dbNDjnjo+9dRA1tLZWpBwMAAdR2Qs9ZmIc5DgCUrhXCtO2qRsjL pAJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720734780; x=1721339580; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=lAClVOPjaYmAqeHOJnomznCPk2DbCytJlAbJtT0EBcU=; b=ntu0jfRlf9104CMJYuKTjkWMuVtSbiwj1Zeg/SjjVDIn9VliCsqtavjVz0icO3nr1w yXee1y/2YcTIxctefxCLH96uQna6VvHQCxGssw2fohXmOCaHUNlbjMv0ZWbc2o0fGA90 VfWDd2vOfPJmAMWwukYOAYXK0JUc4bhzRPOgAlBqI9q+Pzuf4Ce/TA/Ym1PFZMzOPX4j AVpcoBjM4OOm5Hsva68Q6F3H067pjpnIxv+YoXu9DC7oL0JxN6aSxI1bhDxdUXcHSkWY ENZUO11g4h2oiSAmHHaL6KW0KlIB2OvGAI+sOsFTFa1vfle2Tc8SYMCH/Jp8fUfDDhOo Bm6A== X-Forwarded-Encrypted: i=1; AJvYcCXr89t9XPHTzSa0QpOfyWPT0az8rGdGHQPhn5cQOeTL/awJhN9Cm8UyrOgDWITXl3S1g2/86X6uVHefrW5o2VAmsAP8pUo= X-Gm-Message-State: AOJu0YzZEzNs8dDdRvh04xPbknY1SaCN46D7A9vnz0lVwRFWJ5MYSUnl YHOGEaRaQJMx6qtQKYOOuyglE/uSEYQ1cRVUdly/lHL0iFMsUOWVikEHD4F6Z/I= X-Google-Smtp-Source: AGHT+IHhGaHZPvsOOFoJBlZC6j7jksJpDnEgjxRqPRRvjpMOSkZgwavxCc6jUd++pCbDbuTy3E32aQ== X-Received: by 2002:a05:6830:3b84:b0:703:7051:4018 with SMTP id 46e09a7af769-70375a4634dmr10897638a34.28.1720734780412; Thu, 11 Jul 2024 14:53:00 -0700 (PDT) Received: from DY4X0N7X05.bytedance.net ([208.184.112.130]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-7044ac2876dsm713125a34.2.2024.07.11.14.52.57 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 11 Jul 2024 14:53:00 -0700 (PDT) From: Yichen Wang To: Paolo Bonzini , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Thomas Huth , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Peter Xu , Fabiano Rosas , Eric Blake , Markus Armbruster , "Michael S. Tsirkin" , Cornelia Huck , qemu-devel@nongnu.org Cc: "Hao Xiang" , "Liu, Yuan1" , "Shivam Kumar" , "Ho-Ren (Jack) Chuang" , "Yichen Wang" Subject: [PATCH v5 05/13] util/dsa: Implement DSA task asynchronous completion thread model. Date: Thu, 11 Jul 2024 14:52:40 -0700 Message-Id: <20240711215244.19237-6-yichen.wang@bytedance.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20240711215244.19237-1-yichen.wang@bytedance.com> References: <20240711215244.19237-1-yichen.wang@bytedance.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::332; envelope-from=yichen.wang@bytedance.com; helo=mail-ot1-x332.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Hao Xiang * Create a dedicated thread for DSA task completion. * DSA completion thread runs a loop and poll for completed tasks. * Start and stop DSA completion thread during DSA device start stop. User space application can directly submit task to Intel DSA accelerator by writing to DSA's device memory (mapped in user space). Once a task is submitted, the device starts processing it and write the completion status back to the task. A user space application can poll the task's completion status to check for completion. This change uses a dedicated thread to perform DSA task completion checking. Signed-off-by: Hao Xiang Signed-off-by: Yichen Wang --- include/qemu/dsa.h | 1 + util/dsa.c | 274 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 274 insertions(+), 1 deletion(-) diff --git a/include/qemu/dsa.h b/include/qemu/dsa.h index 9cc836b64c..d46a9f42a5 100644 --- a/include/qemu/dsa.h +++ b/include/qemu/dsa.h @@ -69,6 +69,7 @@ typedef struct QemuDsaBatchTask { QemuDsaTaskType task_type; QemuDsaTaskStatus status; int batch_size; + bool *results; QSIMPLEQ_ENTRY(QemuDsaBatchTask) entry; } QemuDsaBatchTask; diff --git a/util/dsa.c b/util/dsa.c index 43280b31cd..1eb85f37f1 100644 --- a/util/dsa.c +++ b/util/dsa.c @@ -33,9 +33,20 @@ #define DSA_WQ_PORTAL_SIZE 4096 #define DSA_WQ_DEPTH 128 #define MAX_DSA_DEVICES 16 +#define DSA_COMPLETION_THREAD "qemu_dsa_completion" + +typedef struct { + bool stopping; + bool running; + QemuThread thread; + int thread_id; + QemuSemaphore sem_init_done; + QemuDsaDeviceGroup *group; +} QemuDsaCompletionThread; uint32_t max_retry_count; static QemuDsaDeviceGroup dsa_group; +static QemuDsaCompletionThread completion_thread; /** @@ -409,6 +420,265 @@ submit_batch_wi_async(QemuDsaBatchTask *batch_task) return dsa_task_enqueue(device_group, batch_task); } +/** + * @brief Poll for the DSA work item completion. + * + * @param completion A pointer to the DSA work item completion record. + * @param opcode The DSA opcode. + * + * @return Zero if successful, non-zero otherwise. + */ +static int +poll_completion(struct dsa_completion_record *completion, + enum dsa_opcode opcode) +{ + uint8_t status; + uint64_t retry = 0; + + while (true) { + /* The DSA operation completes successfully or fails. */ + status = completion->status; + if (status == DSA_COMP_SUCCESS || + status == DSA_COMP_PAGE_FAULT_NOBOF || + status == DSA_COMP_BATCH_PAGE_FAULT || + status == DSA_COMP_BATCH_FAIL) { + break; + } else if (status != DSA_COMP_NONE) { + error_report("DSA opcode %d failed with status = %d.", + opcode, status); + return 1; + } + retry++; + if (retry > max_retry_count) { + error_report("DSA wait for completion retry %lu times.", retry); + return 1; + } + _mm_pause(); + } + + return 0; +} + +/** + * @brief Complete a single DSA task in the batch task. + * + * @param task A pointer to the batch task structure. + * + * @return Zero if successful, otherwise non-zero. + */ +static int +poll_task_completion(QemuDsaBatchTask *task) +{ + assert(task->task_type == QEMU_DSA_TASK); + + struct dsa_completion_record *completion = &task->completions[0]; + uint8_t status; + int ret; + + ret = poll_completion(completion, task->descriptors[0].opcode); + if (ret != 0) { + goto exit; + } + + status = completion->status; + if (status == DSA_COMP_SUCCESS) { + task->results[0] = (completion->result == 0); + goto exit; + } + + assert(status == DSA_COMP_PAGE_FAULT_NOBOF); + +exit: + return ret; +} + +/** + * @brief Poll a batch task status until it completes. If DSA task doesn't + * complete properly, use CPU to complete the task. + * + * @param batch_task A pointer to the DSA batch task. + * + * @return Zero if successful, otherwise non-zero. + */ +static int +poll_batch_task_completion(QemuDsaBatchTask *batch_task) +{ + struct dsa_completion_record *batch_completion = + &batch_task->batch_completion; + struct dsa_completion_record *completion; + uint8_t batch_status; + uint8_t status; + bool *results = batch_task->results; + uint32_t count = batch_task->batch_descriptor.desc_count; + int ret; + + ret = poll_completion(batch_completion, + batch_task->batch_descriptor.opcode); + if (ret != 0) { + goto exit; + } + + batch_status = batch_completion->status; + + if (batch_status == DSA_COMP_SUCCESS) { + if (batch_completion->bytes_completed == count) { + /* + * Let's skip checking for each descriptors' completion status + * if the batch descriptor says all succedded. + */ + for (int i = 0; i < count; i++) { + assert(batch_task->completions[i].status == DSA_COMP_SUCCESS); + results[i] = (batch_task->completions[i].result == 0); + } + goto exit; + } + } else { + assert(batch_status == DSA_COMP_BATCH_FAIL || + batch_status == DSA_COMP_BATCH_PAGE_FAULT); + } + + for (int i = 0; i < count; i++) { + + completion = &batch_task->completions[i]; + status = completion->status; + + if (status == DSA_COMP_SUCCESS) { + results[i] = (completion->result == 0); + continue; + } + + assert(status == DSA_COMP_PAGE_FAULT_NOBOF); + + if (status != DSA_COMP_PAGE_FAULT_NOBOF) { + error_report("Unexpected DSA completion status = %u.", status); + ret = 1; + goto exit; + } + } + +exit: + return ret; +} + +/** + * @brief Handles an asynchronous DSA batch task completion. + * + * @param task A pointer to the batch buffer zero task structure. + */ +static void +dsa_batch_task_complete(QemuDsaBatchTask *batch_task) +{ + batch_task->status = QEMU_DSA_TASK_COMPLETION; + batch_task->completion_callback(batch_task); +} + +/** + * @brief The function entry point called by a dedicated DSA + * work item completion thread. + * + * @param opaque A pointer to the thread context. + * + * @return void* Not used. + */ +static void * +dsa_completion_loop(void *opaque) +{ + QemuDsaCompletionThread *thread_context = + (QemuDsaCompletionThread *)opaque; + QemuDsaBatchTask *batch_task; + QemuDsaDeviceGroup *group = thread_context->group; + int ret; + + rcu_register_thread(); + + thread_context->thread_id = qemu_get_thread_id(); + qemu_sem_post(&thread_context->sem_init_done); + + while (thread_context->running) { + batch_task = dsa_task_dequeue(group); + assert(batch_task != NULL || !group->running); + if (!group->running) { + assert(!thread_context->running); + break; + } + if (batch_task->task_type == QEMU_DSA_TASK) { + ret = poll_task_completion(batch_task); + } else { + assert(batch_task->task_type == QEMU_DSA_BATCH_TASK); + ret = poll_batch_task_completion(batch_task); + } + + if (ret != 0) { + goto exit; + } + + dsa_batch_task_complete(batch_task); + } + +exit: + if (ret != 0) { + error_report("DSA completion thread exited due to internal error."); + } + rcu_unregister_thread(); + return NULL; +} + +/** + * @brief Initializes a DSA completion thread. + * + * @param completion_thread A pointer to the completion thread context. + * @param group A pointer to the DSA device group. + */ +static void +dsa_completion_thread_init( + QemuDsaCompletionThread *completion_thread, + QemuDsaDeviceGroup *group) +{ + completion_thread->stopping = false; + completion_thread->running = true; + completion_thread->thread_id = -1; + qemu_sem_init(&completion_thread->sem_init_done, 0); + completion_thread->group = group; + + qemu_thread_create(&completion_thread->thread, + DSA_COMPLETION_THREAD, + dsa_completion_loop, + completion_thread, + QEMU_THREAD_JOINABLE); + + /* Wait for initialization to complete */ + qemu_sem_wait(&completion_thread->sem_init_done); +} + +/** + * @brief Stops the completion thread (and implicitly, the device group). + * + * @param opaque A pointer to the completion thread. + */ +static void dsa_completion_thread_stop(void *opaque) +{ + QemuDsaCompletionThread *thread_context = + (QemuDsaCompletionThread *)opaque; + + QemuDsaDeviceGroup *group = thread_context->group; + + qemu_mutex_lock(&group->task_queue_lock); + + thread_context->stopping = true; + thread_context->running = false; + + /* Prevent the compiler from setting group->running first. */ + barrier(); + dsa_device_group_stop(group); + + qemu_cond_signal(&group->task_queue_cond); + qemu_mutex_unlock(&group->task_queue_lock); + + qemu_thread_join(&thread_context->thread); + + qemu_sem_destroy(&thread_context->sem_init_done); +} + /** * @brief Check if DSA is running. * @@ -416,7 +686,7 @@ submit_batch_wi_async(QemuDsaBatchTask *batch_task) */ bool qemu_dsa_is_running(void) { - return false; + return completion_thread.running; } static void @@ -452,6 +722,7 @@ void qemu_dsa_start(void) return; } dsa_device_group_start(&dsa_group); + dsa_completion_thread_init(&completion_thread, &dsa_group); } /** @@ -466,6 +737,7 @@ void qemu_dsa_stop(void) return; } + dsa_completion_thread_stop(&completion_thread); dsa_empty_task_queue(group); }