Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   zhenwei pi <pizhenwei@bytedance.com>
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,
        davem@davemloft.net, zhenwei pi <pizhenwei@bytedance.com>
Subject: [PATCH 1/4] virtio-crypto: wait ctrl queue instead of busy polling
Date:   Fri, 15 Apr 2022 14:41:33 +0800
Message-Id: <20220415064136.304661-2-pizhenwei@bytedance.com>
In-Reply-To: <20220415064136.304661-1-pizhenwei@bytedance.com>
References: <20220415064136.304661-1-pizhenwei@bytedance.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Originally, after submitting request into virtio crypto control
queue, the guest side polls the result from the virt queue. 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        |                        |

To improve the performance of control queue, wait completion instead
of busy polling without lock race, and get completed by control queue
callback. Test this patch, the guest side get ~200K/s operations with
300% CPU utilization.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 drivers/crypto/virtio/Makefile                |   1 +
 .../virtio/virtio_crypto_akcipher_algs.c      |  87 ++++++------
 drivers/crypto/virtio/virtio_crypto_common.c  |  61 ++++++++
 drivers/crypto/virtio/virtio_crypto_common.h  |  23 ++-
 drivers/crypto/virtio/virtio_crypto_core.c    |   2 +-
 .../virtio/virtio_crypto_skcipher_algs.c      | 134 ++++++++----------
 6 files changed, 183 insertions(+), 125 deletions(-)
 create mode 100644 drivers/crypto/virtio/virtio_crypto_common.c

diff --git a/drivers/crypto/virtio/Makefile b/drivers/crypto/virtio/Makefile
index bfa6cbae342e..49c1fa80e465 100644
--- a/drivers/crypto/virtio/Makefile
+++ b/drivers/crypto/virtio/Makefile
@@ -3,5 +3,6 @@ obj-$(CONFIG_CRYPTO_DEV_VIRTIO) += virtio_crypto.o
 virtio_crypto-objs := \
 	virtio_crypto_skcipher_algs.o \
 	virtio_crypto_akcipher_algs.o \
+	virtio_crypto_common.o \
 	virtio_crypto_mgr.o \
 	virtio_crypto_core.o
diff --git a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
index f3ec9420215e..bf7c1aa4be37 100644
--- a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
@@ -102,107 +102,100 @@ 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;
+	struct virtio_crypto_ctrl_request *vc_ctrl_req = NULL;
 	uint8_t *pkey;
-	unsigned int inlen;
-	int err;
+	int err = -ENOMEM;
 	unsigned int num_out = 0, num_in = 0;
+	int node = dev_to_node(&vcrypto->vdev->dev);
 
 	pkey = kmemdup(key, keylen, GFP_ATOMIC);
 	if (!pkey)
 		return -ENOMEM;
 
-	spin_lock(&vcrypto->ctrl_lock);
-	memcpy(&vcrypto->ctrl.header, header, sizeof(vcrypto->ctrl.header));
-	memcpy(&vcrypto->ctrl.u, para, sizeof(vcrypto->ctrl.u));
-	vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
+	vc_ctrl_req = kzalloc_node(sizeof(*vc_ctrl_req), GFP_KERNEL, node);
+	if (!vc_ctrl_req)
+		goto out;
 
-	sg_init_one(&outhdr_sg, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	memcpy(&vc_ctrl_req->ctrl.header, header, sizeof(vc_ctrl_req->ctrl.header));
+	memcpy(&vc_ctrl_req->ctrl.u, para, sizeof(vc_ctrl_req->ctrl.u));
+	sg_init_one(&outhdr_sg, &vc_ctrl_req->ctrl, sizeof(vc_ctrl_req->ctrl));
 	sgs[num_out++] = &outhdr_sg;
 
 	sg_init_one(&key_sg, pkey, keylen);
 	sgs[num_out++] = &key_sg;
 
-	sg_init_one(&inhdr_sg, &vcrypto->input, sizeof(vcrypto->input));
+	vc_ctrl_req->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
+	sg_init_one(&inhdr_sg, &vc_ctrl_req->input, sizeof(vc_ctrl_req->input));
 	sgs[num_out + num_in++] = &inhdr_sg;
 
-	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out, num_in, vcrypto, GFP_ATOMIC);
+	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();
-
-	if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
+	if (le32_to_cpu(vc_ctrl_req->input.status) != VIRTIO_CRYPTO_OK) {
+		pr_err("virtio_crypto: Create session failed status: %u\n",
+			le32_to_cpu(vc_ctrl_req->input.status));
 		err = -EINVAL;
 		goto out;
 	}
 
-	ctx->session_id = le64_to_cpu(vcrypto->input.session_id);
+	ctx->session_id = le64_to_cpu(vc_ctrl_req->input.session_id);
 	ctx->session_valid = true;
 	err = 0;
 
 out:
-	spin_unlock(&vcrypto->ctrl_lock);
+	kfree_sensitive(vc_ctrl_req);
 	kfree_sensitive(pkey);
 
-	if (err < 0)
-		pr_err("virtio_crypto: Create session failed status: %u\n",
-			le32_to_cpu(vcrypto->input.status));
-
 	return err;
 }
 
 static int virtio_crypto_alg_akcipher_close_session(struct virtio_crypto_akcipher_ctx *ctx)
 {
 	struct scatterlist outhdr_sg, inhdr_sg, *sgs[2];
+	struct virtio_crypto_ctrl_request *vc_ctrl_req = NULL;
 	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;
+	int node = dev_to_node(&vcrypto->vdev->dev);
 
-	spin_lock(&vcrypto->ctrl_lock);
-	if (!ctx->session_valid) {
-		err = 0;
-		goto out;
-	}
-	vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
-	vcrypto->ctrl.header.opcode = cpu_to_le32(VIRTIO_CRYPTO_AKCIPHER_DESTROY_SESSION);
-	vcrypto->ctrl.header.queue_id = 0;
+	if (!ctx->session_valid)
+		return 0;
+
+	vc_ctrl_req = kzalloc_node(sizeof(*vc_ctrl_req), GFP_KERNEL, node);
+	if (!vc_ctrl_req)
+		return -ENOMEM;
 
-	destroy_session = &vcrypto->ctrl.u.destroy_session;
+	vc_ctrl_req->ctrl.header.opcode = cpu_to_le32(VIRTIO_CRYPTO_AKCIPHER_DESTROY_SESSION);
+	vc_ctrl_req->ctrl.header.queue_id = 0;
+
+	destroy_session = &vc_ctrl_req->ctrl.u.destroy_session;
 	destroy_session->session_id = cpu_to_le64(ctx->session_id);
 
-	sg_init_one(&outhdr_sg, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	sg_init_one(&outhdr_sg, &vc_ctrl_req->ctrl, sizeof(vc_ctrl_req->ctrl));
 	sgs[num_out++] = &outhdr_sg;
 
-	sg_init_one(&inhdr_sg, &vcrypto->ctrl_status.status, sizeof(vcrypto->ctrl_status.status));
+	vc_ctrl_req->ctrl_status.status = VIRTIO_CRYPTO_ERR;
+	sg_init_one(&inhdr_sg, &vc_ctrl_req->ctrl_status.status,
+		sizeof(vc_ctrl_req->ctrl_status.status));
 	sgs[num_out + num_in++] = &inhdr_sg;
 
-	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out, num_in, vcrypto, GFP_ATOMIC);
+	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();
-
-	if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
+	if (vc_ctrl_req->ctrl_status.status != VIRTIO_CRYPTO_OK) {
 		err = -EINVAL;
+		pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
+			vc_ctrl_req->ctrl_status.status, destroy_session->session_id);
 		goto out;
 	}
 
-	err = 0;
 	ctx->session_valid = false;
-
+	err = 0;
 out:
-	spin_unlock(&vcrypto->ctrl_lock);
-	if (err < 0) {
-		pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
-			vcrypto->ctrl_status.status, destroy_session->session_id);
-	}
+	kfree_sensitive(vc_ctrl_req);
 
 	return err;
 }
diff --git a/drivers/crypto/virtio/virtio_crypto_common.c b/drivers/crypto/virtio/virtio_crypto_common.c
new file mode 100644
index 000000000000..93df73c40dd3
--- /dev/null
+++ b/drivers/crypto/virtio/virtio_crypto_common.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Common functions and helpers
+ *
+ * Authors: zhenwei pi <pizhenwei@bytedance.com>
+ *
+ * Copyright 2022 Bytedance CO., LTD.
+ */
+
+#include "virtio_crypto_common.h"
+
+static void virtio_crypto_ctrlq_callback(struct virtio_crypto_ctrl_request *vc_ctrl_req)
+{
+	complete(&vc_ctrl_req->compl);
+}
+
+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);
+	vc_ctrl_req->ctrl_cb =  virtio_crypto_ctrlq_callback;
+
+	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;
+}
+
+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);
+			if (vc_ctrl_req->ctrl_cb)
+				vc_ctrl_req->ctrl_cb(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);
+}
diff --git a/drivers/crypto/virtio/virtio_crypto_common.h b/drivers/crypto/virtio/virtio_crypto_common.h
index e693d4ee83a6..125ad2300b83 100644
--- a/drivers/crypto/virtio/virtio_crypto_common.h
+++ b/drivers/crypto/virtio/virtio_crypto_common.h
@@ -13,6 +13,7 @@
 #include <crypto/aead.h>
 #include <crypto/aes.h>
 #include <crypto/engine.h>
+#include <uapi/linux/virtio_crypto.h>
 
 
 /* Internal representation of a data virtqueue */
@@ -65,11 +66,6 @@ struct virtio_crypto {
 	/* Maximum size of per request */
 	u64 max_size;
 
-	/* Control VQ buffers: protected by the ctrl_lock */
-	struct virtio_crypto_op_ctrl_req ctrl;
-	struct virtio_crypto_session_input input;
-	struct virtio_crypto_inhdr ctrl_status;
-
 	unsigned long status;
 	atomic_t ref_count;
 	struct list_head list;
@@ -85,6 +81,18 @@ struct virtio_crypto_sym_session_info {
 	__u64 session_id;
 };
 
+struct virtio_crypto_ctrl_request;
+typedef void (*virtio_crypto_ctrl_callback)
+		(struct virtio_crypto_ctrl_request *vc_ctrl_req);
+
+struct virtio_crypto_ctrl_request {
+	struct virtio_crypto_op_ctrl_req ctrl;
+	struct virtio_crypto_session_input input;
+	struct virtio_crypto_inhdr ctrl_status;
+	virtio_crypto_ctrl_callback ctrl_cb;
+	struct completion compl;
+};
+
 struct virtio_crypto_request;
 typedef void (*virtio_crypto_data_callback)
 		(struct virtio_crypto_request *vc_req, int len);
@@ -135,4 +143,9 @@ 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);
 
+void virtcrypto_ctrlq_callback(struct virtqueue *vq);
+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..e668d4b1bc6a 100644
--- a/drivers/crypto/virtio/virtio_crypto_core.c
+++ b/drivers/crypto/virtio/virtio_crypto_core.c
@@ -73,7 +73,7 @@ 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 a618c46a52b8..b8999dab3e66 100644
--- a/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c
@@ -118,11 +118,14 @@ 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;
+	int err = -ENOMEM;
 	unsigned int num_out = 0, num_in = 0;
+	struct virtio_crypto_ctrl_request *vc_ctrl_req = NULL;
+	struct virtio_crypto_ctrl_header *header;
+	struct virtio_crypto_sym_create_session_req *sym_create_session;
+	int node = dev_to_node(&vcrypto->vdev->dev);
 
 	/*
 	 * Avoid to do DMA from the stack, switch to using
@@ -133,26 +136,25 @@ static int virtio_crypto_alg_skcipher_init_session(
 	if (!cipher_key)
 		return -ENOMEM;
 
-	spin_lock(&vcrypto->ctrl_lock);
+	vc_ctrl_req = kzalloc_node(sizeof(*vc_ctrl_req), GFP_KERNEL, node);
+	if (!vc_ctrl_req)
+		goto out;
+
 	/* Pad ctrl header */
-	vcrypto->ctrl.header.opcode =
-		cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
-	vcrypto->ctrl.header.algo = cpu_to_le32(alg);
+	header = &vc_ctrl_req->ctrl.header;
+	header->opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
+	header->algo = cpu_to_le32(alg);
 	/* Set the default dataqueue id to 0 */
-	vcrypto->ctrl.header.queue_id = 0;
+	header->queue_id = 0;
 
-	vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
 	/* Pad cipher's parameters */
-	vcrypto->ctrl.u.sym_create_session.op_type =
-		cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
-	vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
-		vcrypto->ctrl.header.algo;
-	vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
-		cpu_to_le32(keylen);
-	vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
-		cpu_to_le32(op);
-
-	sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	sym_create_session = &vc_ctrl_req->ctrl.u.sym_create_session;
+	sym_create_session->op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
+	sym_create_session->u.cipher.para.algo = header->algo;
+	sym_create_session->u.cipher.para.keylen = cpu_to_le32(keylen);
+	sym_create_session->u.cipher.para.op = cpu_to_le32(op);
+
+	sg_init_one(&outhdr, &vc_ctrl_req->ctrl, sizeof(vc_ctrl_req->ctrl));
 	sgs[num_out++] = &outhdr;
 
 	/* Set key */
@@ -160,45 +162,34 @@ static int virtio_crypto_alg_skcipher_init_session(
 	sgs[num_out++] = &key_sg;
 
 	/* Return status and session id back */
-	sg_init_one(&inhdr, &vcrypto->input, sizeof(vcrypto->input));
+	vc_ctrl_req->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
+	sg_init_one(&inhdr, &vc_ctrl_req->input, sizeof(vc_ctrl_req->input));
 	sgs[num_out + num_in++] = &inhdr;
 
-	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
-				num_in, vcrypto, GFP_ATOMIC);
-	if (err < 0) {
-		spin_unlock(&vcrypto->ctrl_lock);
-		kfree_sensitive(cipher_key);
-		return err;
-	}
-	virtqueue_kick(vcrypto->ctrl_vq);
+	err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req);
+	if (err < 0)
+		goto out;
 
-	/*
-	 * 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();
-
-	if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
-		spin_unlock(&vcrypto->ctrl_lock);
+	if (le32_to_cpu(vc_ctrl_req->input.status) != VIRTIO_CRYPTO_OK) {
 		pr_err("virtio_crypto: Create session failed status: %u\n",
-			le32_to_cpu(vcrypto->input.status));
-		kfree_sensitive(cipher_key);
-		return -EINVAL;
+			le32_to_cpu(vc_ctrl_req->input.status));
+		err = -EINVAL;
+		goto out;
 	}
 
 	if (encrypt)
 		ctx->enc_sess_info.session_id =
-			le64_to_cpu(vcrypto->input.session_id);
+			le64_to_cpu(vc_ctrl_req->input.session_id);
 	else
 		ctx->dec_sess_info.session_id =
-			le64_to_cpu(vcrypto->input.session_id);
-
-	spin_unlock(&vcrypto->ctrl_lock);
+			le64_to_cpu(vc_ctrl_req->input.session_id);
 
+	err = 0;
+out:
+	kfree_sensitive(vc_ctrl_req);
 	kfree_sensitive(cipher_key);
-	return 0;
+
+	return err;
 }
 
 static int virtio_crypto_alg_skcipher_close_session(
@@ -206,21 +197,25 @@ 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;
 	unsigned int num_out = 0, num_in = 0;
+	struct virtio_crypto_ctrl_request *vc_ctrl_req = NULL;
+	struct virtio_crypto_ctrl_header *header;
+	int node = dev_to_node(&vcrypto->vdev->dev);
+
+	vc_ctrl_req = kzalloc_node(sizeof(*vc_ctrl_req), GFP_KERNEL, node);
+	if (!vc_ctrl_req)
+		return -ENOMEM;
 
-	spin_lock(&vcrypto->ctrl_lock);
-	vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
 	/* Pad ctrl header */
-	vcrypto->ctrl.header.opcode =
-		cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
+	header = &vc_ctrl_req->ctrl.header;
+	header->opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
 	/* Set the default virtqueue id to 0 */
-	vcrypto->ctrl.header.queue_id = 0;
+	header->queue_id = 0;
 
-	destroy_session = &vcrypto->ctrl.u.destroy_session;
+	destroy_session = &vc_ctrl_req->ctrl.u.destroy_session;
 
 	if (encrypt)
 		destroy_session->session_id =
@@ -229,37 +224,32 @@ static int virtio_crypto_alg_skcipher_close_session(
 		destroy_session->session_id =
 			cpu_to_le64(ctx->dec_sess_info.session_id);
 
-	sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	sg_init_one(&outhdr, &vc_ctrl_req->ctrl, sizeof(vc_ctrl_req->ctrl));
 	sgs[num_out++] = &outhdr;
 
 	/* Return status and session id back */
-	sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
-		sizeof(vcrypto->ctrl_status.status));
+	vc_ctrl_req->ctrl_status.status = VIRTIO_CRYPTO_ERR;
+	sg_init_one(&status_sg, &vc_ctrl_req->ctrl_status.status,
+		sizeof(vc_ctrl_req->ctrl_status.status));
 	sgs[num_out + num_in++] = &status_sg;
 
-	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
-			num_in, vcrypto, GFP_ATOMIC);
-	if (err < 0) {
-		spin_unlock(&vcrypto->ctrl_lock);
-		return err;
-	}
-	virtqueue_kick(vcrypto->ctrl_vq);
-
-	while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
-	       !virtqueue_is_broken(vcrypto->ctrl_vq))
-		cpu_relax();
+	err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req);
+	if (err < 0)
+		goto out;
 
-	if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
-		spin_unlock(&vcrypto->ctrl_lock);
+	if (vc_ctrl_req->ctrl_status.status != VIRTIO_CRYPTO_OK) {
 		pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
-			vcrypto->ctrl_status.status,
+			vc_ctrl_req->ctrl_status.status,
 			destroy_session->session_id);
 
-		return -EINVAL;
+		err = -EINVAL;
 	}
-	spin_unlock(&vcrypto->ctrl_lock);
 
-	return 0;
+	err = 0;
+out:
+	kfree_sensitive(vc_ctrl_req);
+
+	return err;
 }
 
 static int virtio_crypto_alg_skcipher_init_sessions(
-- 
2.20.1