From patchwork Thu May 5 09:24:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: zhenwei pi X-Patchwork-Id: 12839286 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 B1DA0C433EF for ; Thu, 5 May 2022 09:29:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353599AbiEEJcv (ORCPT ); Thu, 5 May 2022 05:32:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354420AbiEEJc2 (ORCPT ); Thu, 5 May 2022 05:32:28 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86A7F53A73 for ; Thu, 5 May 2022 02:28:19 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id cq17-20020a17090af99100b001dc0386cd8fso3586192pjb.5 for ; Thu, 05 May 2022 02:28:19 -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=1l8IF2nuZK7JNFwfctUmwx+e3ubrs2XnEcxOxHD4Ax0=; b=Bf/s7+BJwqAM3h3XFVp+nCGX2Sx9rnNc4m6bDsD9zDkCTVKKhrgOl6uP8wBqebPJbO Jshko5JhvHhK4WLhInBRN1XbjUImpkC5XQk8LBJhEPSOPZHjHnAU2GIIxpqUXXHj6IaD oE9eINo87khzb8cD5wArgbd6u7RbtfpCJswQHOIZ0csWsOLFAz4ZjNWLDQOLCd2HK+IA GH5opDmXnfn3aeDqyOK/EHkeKpkMTLLs3ktTUpAKYbl66wTa9D4bsq3OJl/EgybQAnuN aOTc6Gt7x3Q+D0HHsEOuJbfW2hsaLHN7zUN74SPDLhZvgCUxgIHGnilv3i6DodqbxyJa JaZQ== 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=1l8IF2nuZK7JNFwfctUmwx+e3ubrs2XnEcxOxHD4Ax0=; b=uqHSZrMp3u2578YKkXmmAjsqC8V6L/meRF9//Sz/5erv/xolbI15i+rdFnSfr9X0jM AWVobQbksxBCAdO+mWqmg+HD9vhSo2YyD/LtoUJCg0PlWDG3JNj2n1gqTmNddgvaAsMf 5dVHoXSM74I0CIAhd9skzgnmeaCLtRqHtN4iYkVFZRMWlpsXamSG7RjHYI6hSGCOSw5N KioxIVU+BHWA9SsrfJj5a+tgW5ywd5xFReKoBwb8RnezxZ/0l9zuunyNYktiBkYIhVP6 1xSDm1sZVOoH6JsKRbE2do9Oufeb5x9TmxWFWQN9HHOfuprNDCnPNjchapU5hXAVikPk VOGQ== X-Gm-Message-State: AOAM533QHCyDDCY+gq1U29uCLBHuKtV96/8/EeF+cLhAYEF+NSsc8uHe S8Ahiyq2x5bQSMypEy6YxAdHeQ== X-Google-Smtp-Source: ABdhPJxklYw3bJhRLnHmLUpd0ksLjng4j66bquSzHi7cmKR9OPh0Bon2qfj4wDz72f81juYmTm1g8w== X-Received: by 2002:a17:903:22ce:b0:15e:bd57:5bec with SMTP id y14-20020a17090322ce00b0015ebd575becmr10934475plg.114.1651742898765; Thu, 05 May 2022 02:28:18 -0700 (PDT) Received: from always-x1.www.tendawifi.com ([139.177.225.255]) by smtp.gmail.com with ESMTPSA id t68-20020a625f47000000b0050dc76281dcsm884224pfb.182.2022.05.05.02.28.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 May 2022 02:28:18 -0700 (PDT) From: zhenwei pi To: arei.gonglei@huawei.com, mst@redhat.com Cc: jasowang@redhat.com, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-crypto@vger.kernel.org, helei.sig11@bytedance.com, pizhenwei@bytedance.com, davem@davemloft.net Subject: [PATCH v5 3/5] virtio-crypto: wait ctrl queue instead of busy polling Date: Thu, 5 May 2022 17:24:06 +0800 Message-Id: <20220505092408.53692-4-pizhenwei@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220505092408.53692-1-pizhenwei@bytedance.com> References: <20220505092408.53692-1-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 Reviewed-by: Gonglei --- .../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 698ea57e2649..382ccec9ab12 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) { pr_err("virtio_crypto: Create session failed status: %u\n", @@ -171,7 +161,7 @@ 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; @@ -199,18 +189,9 @@ 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) { pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n", 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",