From patchwork Sun Apr 24 10:41:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: zhenwei pi X-Patchwork-Id: 12824855 X-Patchwork-Delegate: herbert@gondor.apana.org.au 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E922EC433FE for ; Sun, 24 Apr 2022 10:46:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239117AbiDXKtD (ORCPT ); Sun, 24 Apr 2022 06:49:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236966AbiDXKtC (ORCPT ); Sun, 24 Apr 2022 06:49:02 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17A2122B03 for ; Sun, 24 Apr 2022 03:45:50 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id n18so20824328plg.5 for ; Sun, 24 Apr 2022 03:45:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=apUEf+EzBMbf1428+G4F3xeQ1aPIlddSTbIvkpGqC5w=; b=FngY3yqrzabvD/vuacUhlAn1J8NpUUinNeZzIt2T5wCHW3Sy0Kl/Y409vF0FIFNTpi +0YfeS3OYwpHT45QBeS1QieVSkwbA5ObJAhlJEDaOrPDz0J4Kb9oC+aipahZLqKivlPv gmC+Kh0UN8n64HPsLZSJ1b4KJConLmGm/ZveTvYn91MiubkNeua8hmNjC5AFsugCbMqU NdxPNI4HAABL7KoLWYoWp9oPkmKZ3OE9KOC1IYhHUY3JC3ikEq94R3B//HhoVzD7JK7U SkQPoD6yfGJDszULVthoNJgtuvvs1nIjRu7PnCvXl/AxrBCMY4fAUSP1PLkqv8+vDrEF 1OTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=apUEf+EzBMbf1428+G4F3xeQ1aPIlddSTbIvkpGqC5w=; b=bXYWxNrqRUnbftjrGn4C3NIiQfUcWgu/FSfBHzJryVWS/pLDDjAlOF9qrS9QiW6J6O JnU0AmVt+waki3WYnPgALRAa6Mxk+mWDc5jXovhOw50gu20qNmkDNYFSg4MgkkhQoFwz s1PE9R3k4eoiyDX8DLz7CmDn203WfD+ROCO1rDVF60PP0vbJ7TWi0dURYhS/brd6eKah 65PvaMs/sd88pM98ybbeaZum6QnSFoM20Poq14vn6D9D1X6XnOWVJhbOwTkRcE9wyYVc tjh9g6PuGWukXiK9QqbiTNrXkmqQKiF/txIQVkG8pFZXRso0DdXdqr+9LF6NvxuOAzmq nXAw== X-Gm-Message-State: AOAM531Pk0i7E9cB20DG/eMeRouq1nBfHvzMr8z2sOAi89qgjkFXUoSU GnjK0lTaEeQ7ggY6hA2tphaGvw== X-Google-Smtp-Source: ABdhPJw5tSMenUvXwvNJ2sg0MUqVtoTzn/dzDU3c5kJs4cn50ytjtpzIU9gIGra6dulic/qFQbW2RQ== X-Received: by 2002:a17:902:f787:b0:152:157:eb7 with SMTP id q7-20020a170902f78700b0015201570eb7mr12677644pln.109.1650797149603; Sun, 24 Apr 2022 03:45:49 -0700 (PDT) Received: from always-x1.bytedance.net ([61.120.150.70]) by smtp.gmail.com with ESMTPSA id y2-20020a056a00190200b004fa865d1fd3sm8287295pfi.86.2022.04.24.03.45.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 24 Apr 2022 03:45:49 -0700 (PDT) From: zhenwei pi To: arei.gonglei@huawei.com, mst@redhat.com, jasowang@redhat.com Cc: herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-crypto@vger.kernel.org, helei.sig11@bytedance.com, davem@davemloft.net, zhenwei pi Subject: [PATCH v4 3/5] virtio-crypto: wait ctrl queue instead of busy polling Date: Sun, 24 Apr 2022 18:41:38 +0800 Message-Id: <20220424104140.44841-4-pizhenwei@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220424104140.44841-1-pizhenwei@bytedance.com> References: <20220424104140.44841-1-pizhenwei@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Originally, after submitting request into virtio crypto control queue, the guest side polls the result from the virt queue. This works like following: CPU0 CPU1 ... CPUx CPUy | | | | \ \ / / \--------spin_lock(&vcrypto->ctrl_lock)-------/ | virtqueue add & kick | busy poll virtqueue | spin_unlock(&vcrypto->ctrl_lock) ... There are two problems: 1, The queue depth is always 1, the performance of a virtio crypto device gets limited. Multi user processes share a single control queue, and hit spin lock race from control queue. Test on Intel Platinum 8260, a single worker gets ~35K/s create/close session operations, and 8 workers get ~40K/s operations with 800% CPU utilization. 2, The control request is supposed to get handled immediately, but in the current implementation of QEMU(v6.2), the vCPU thread kicks another thread to do this work, the latency also gets unstable. Tracking latency of virtio_crypto_alg_akcipher_close_session in 5s: usecs : count distribution 0 -> 1 : 0 | | 2 -> 3 : 7 | | 4 -> 7 : 72 | | 8 -> 15 : 186485 |************************| 16 -> 31 : 687 | | 32 -> 63 : 5 | | 64 -> 127 : 3 | | 128 -> 255 : 1 | | 256 -> 511 : 0 | | 512 -> 1023 : 0 | | 1024 -> 2047 : 0 | | 2048 -> 4095 : 0 | | 4096 -> 8191 : 0 | | 8192 -> 16383 : 2 | | This means that a CPU may hold vcrypto->ctrl_lock as long as 8192~16383us. To improve the performance of control queue, a request on control queue waits completion instead of busy polling to reduce lock racing, and gets completed by control queue callback. CPU0 CPU1 ... CPUx CPUy | | | | \ \ / / \--------spin_lock(&vcrypto->ctrl_lock)-------/ | virtqueue add & kick | ---------spin_unlock(&vcrypto->ctrl_lock)------ / / \ \ | | | | wait wait wait wait Test this patch, the guest side get ~200K/s operations with 300% CPU utilization. Cc: Michael S. Tsirkin Cc: Jason Wang Cc: Gonglei Signed-off-by: zhenwei pi --- .../virtio/virtio_crypto_akcipher_algs.c | 29 ++--------- drivers/crypto/virtio/virtio_crypto_common.h | 4 ++ drivers/crypto/virtio/virtio_crypto_core.c | 52 ++++++++++++++++++- .../virtio/virtio_crypto_skcipher_algs.c | 34 ++---------- 4 files changed, 64 insertions(+), 55 deletions(-) diff --git a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c index 509884e8b201..1e98502830cf 100644 --- a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c +++ b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c @@ -103,7 +103,6 @@ static int virtio_crypto_alg_akcipher_init_session(struct virtio_crypto_akcipher struct scatterlist outhdr_sg, key_sg, inhdr_sg, *sgs[3]; struct virtio_crypto *vcrypto = ctx->vcrypto; uint8_t *pkey; - unsigned int inlen; int err; unsigned int num_out = 0, num_in = 0; struct virtio_crypto_op_ctrl_req *ctrl; @@ -135,18 +134,9 @@ static int virtio_crypto_alg_akcipher_init_session(struct virtio_crypto_akcipher sg_init_one(&inhdr_sg, input, sizeof(*input)); sgs[num_out + num_in++] = &inhdr_sg; - spin_lock(&vcrypto->ctrl_lock); - err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out, num_in, vcrypto, GFP_ATOMIC); - if (err < 0) { - spin_unlock(&vcrypto->ctrl_lock); + err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req); + if (err < 0) goto out; - } - - virtqueue_kick(vcrypto->ctrl_vq); - while (!virtqueue_get_buf(vcrypto->ctrl_vq, &inlen) && - !virtqueue_is_broken(vcrypto->ctrl_vq)) - cpu_relax(); - spin_unlock(&vcrypto->ctrl_lock); if (le32_to_cpu(input->status) != VIRTIO_CRYPTO_OK) { err = -EINVAL; @@ -173,7 +163,7 @@ static int virtio_crypto_alg_akcipher_close_session(struct virtio_crypto_akciphe struct scatterlist outhdr_sg, inhdr_sg, *sgs[2]; struct virtio_crypto_destroy_session_req *destroy_session; struct virtio_crypto *vcrypto = ctx->vcrypto; - unsigned int num_out = 0, num_in = 0, inlen; + unsigned int num_out = 0, num_in = 0; int err; struct virtio_crypto_op_ctrl_req *ctrl; struct virtio_crypto_inhdr *ctrl_status; @@ -205,18 +195,9 @@ static int virtio_crypto_alg_akcipher_close_session(struct virtio_crypto_akciphe sg_init_one(&inhdr_sg, &ctrl_status->status, sizeof(ctrl_status->status)); sgs[num_out + num_in++] = &inhdr_sg; - spin_lock(&vcrypto->ctrl_lock); - err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out, num_in, vcrypto, GFP_ATOMIC); - if (err < 0) { - spin_unlock(&vcrypto->ctrl_lock); + err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req); + if (err < 0) goto out; - } - - virtqueue_kick(vcrypto->ctrl_vq); - while (!virtqueue_get_buf(vcrypto->ctrl_vq, &inlen) && - !virtqueue_is_broken(vcrypto->ctrl_vq)) - cpu_relax(); - spin_unlock(&vcrypto->ctrl_lock); if (ctrl_status->status != VIRTIO_CRYPTO_OK) { err = -EINVAL; diff --git a/drivers/crypto/virtio/virtio_crypto_common.h b/drivers/crypto/virtio/virtio_crypto_common.h index 2422237ec4e6..59a4c0259456 100644 --- a/drivers/crypto/virtio/virtio_crypto_common.h +++ b/drivers/crypto/virtio/virtio_crypto_common.h @@ -90,6 +90,7 @@ struct virtio_crypto_ctrl_request { struct virtio_crypto_op_ctrl_req ctrl; struct virtio_crypto_session_input input; struct virtio_crypto_inhdr ctrl_status; + struct completion compl; }; struct virtio_crypto_request; @@ -141,5 +142,8 @@ int virtio_crypto_skcipher_algs_register(struct virtio_crypto *vcrypto); void virtio_crypto_skcipher_algs_unregister(struct virtio_crypto *vcrypto); int virtio_crypto_akcipher_algs_register(struct virtio_crypto *vcrypto); void virtio_crypto_akcipher_algs_unregister(struct virtio_crypto *vcrypto); +int virtio_crypto_ctrl_vq_request(struct virtio_crypto *vcrypto, struct scatterlist *sgs[], + unsigned int out_sgs, unsigned int in_sgs, + struct virtio_crypto_ctrl_request *vc_ctrl_req); #endif /* _VIRTIO_CRYPTO_COMMON_H */ diff --git a/drivers/crypto/virtio/virtio_crypto_core.c b/drivers/crypto/virtio/virtio_crypto_core.c index c6f482db0bc0..60490ffa3df1 100644 --- a/drivers/crypto/virtio/virtio_crypto_core.c +++ b/drivers/crypto/virtio/virtio_crypto_core.c @@ -22,6 +22,56 @@ virtcrypto_clear_request(struct virtio_crypto_request *vc_req) } } +static void virtio_crypto_ctrlq_callback(struct virtio_crypto_ctrl_request *vc_ctrl_req) +{ + complete(&vc_ctrl_req->compl); +} + +static void virtcrypto_ctrlq_callback(struct virtqueue *vq) +{ + struct virtio_crypto *vcrypto = vq->vdev->priv; + struct virtio_crypto_ctrl_request *vc_ctrl_req; + unsigned long flags; + unsigned int len; + + spin_lock_irqsave(&vcrypto->ctrl_lock, flags); + do { + virtqueue_disable_cb(vq); + while ((vc_ctrl_req = virtqueue_get_buf(vq, &len)) != NULL) { + spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags); + virtio_crypto_ctrlq_callback(vc_ctrl_req); + spin_lock_irqsave(&vcrypto->ctrl_lock, flags); + } + if (unlikely(virtqueue_is_broken(vq))) + break; + } while (!virtqueue_enable_cb(vq)); + spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags); +} + +int virtio_crypto_ctrl_vq_request(struct virtio_crypto *vcrypto, struct scatterlist *sgs[], + unsigned int out_sgs, unsigned int in_sgs, + struct virtio_crypto_ctrl_request *vc_ctrl_req) +{ + int err; + unsigned long flags; + + init_completion(&vc_ctrl_req->compl); + + spin_lock_irqsave(&vcrypto->ctrl_lock, flags); + err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, out_sgs, in_sgs, vc_ctrl_req, GFP_ATOMIC); + if (err < 0) { + spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags); + return err; + } + + virtqueue_kick(vcrypto->ctrl_vq); + spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags); + + wait_for_completion(&vc_ctrl_req->compl); + + return 0; +} + static void virtcrypto_dataq_callback(struct virtqueue *vq) { struct virtio_crypto *vcrypto = vq->vdev->priv; @@ -73,7 +123,7 @@ static int virtcrypto_find_vqs(struct virtio_crypto *vi) goto err_names; /* Parameters for control virtqueue */ - callbacks[total_vqs - 1] = NULL; + callbacks[total_vqs - 1] = virtcrypto_ctrlq_callback; names[total_vqs - 1] = "controlq"; /* Allocate/initialize parameters for data virtqueues */ diff --git a/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c b/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c index 6aaf0869b211..e553ccadbcbc 100644 --- a/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c +++ b/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c @@ -118,7 +118,6 @@ static int virtio_crypto_alg_skcipher_init_session( int encrypt) { struct scatterlist outhdr, key_sg, inhdr, *sgs[3]; - unsigned int tmp; struct virtio_crypto *vcrypto = ctx->vcrypto; int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT; int err; @@ -170,23 +169,9 @@ static int virtio_crypto_alg_skcipher_init_session( sg_init_one(&inhdr, input, sizeof(*input)); sgs[num_out + num_in++] = &inhdr; - spin_lock(&vcrypto->ctrl_lock); - err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out, - num_in, vcrypto, GFP_ATOMIC); - if (err < 0) { - spin_unlock(&vcrypto->ctrl_lock); + err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req); + if (err < 0) goto out; - } - virtqueue_kick(vcrypto->ctrl_vq); - - /* - * Trapping into the hypervisor, so the request should be - * handled immediately. - */ - while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) && - !virtqueue_is_broken(vcrypto->ctrl_vq)) - cpu_relax(); - spin_unlock(&vcrypto->ctrl_lock); if (le32_to_cpu(input->status) != VIRTIO_CRYPTO_OK) { pr_err("virtio_crypto: Create session failed status: %u\n", @@ -212,7 +197,6 @@ static int virtio_crypto_alg_skcipher_close_session( int encrypt) { struct scatterlist outhdr, status_sg, *sgs[2]; - unsigned int tmp; struct virtio_crypto_destroy_session_req *destroy_session; struct virtio_crypto *vcrypto = ctx->vcrypto; int err; @@ -247,19 +231,9 @@ static int virtio_crypto_alg_skcipher_close_session( sg_init_one(&status_sg, &ctrl_status->status, sizeof(ctrl_status->status)); sgs[num_out + num_in++] = &status_sg; - spin_lock(&vcrypto->ctrl_lock); - err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out, - num_in, vcrypto, GFP_ATOMIC); - if (err < 0) { - spin_unlock(&vcrypto->ctrl_lock); + err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req); + if (err < 0) goto out; - } - virtqueue_kick(vcrypto->ctrl_vq); - - while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) && - !virtqueue_is_broken(vcrypto->ctrl_vq)) - cpu_relax(); - spin_unlock(&vcrypto->ctrl_lock); if (ctrl_status->status != VIRTIO_CRYPTO_OK) { pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",