Revision 6e474083f3daf3a3546737f5d7d502ad12eb257c authored by Wei Xu on 01 December 2017, 10:10:36 UTC, committed by David S. Miller on 03 December 2017, 02:31:03 UTC
Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev@vger.kernel.org/msg187936.html Eventually we figured out that it was a skb leak in handle_rx() when sending packets to the VM. This usually happens when a guest can not drain out vq as fast as vhost fills in, afterwards it sets off the traffic jam and leaks skb(s) which occurs as no headcount to send on the vq from vhost side. This can be avoided by making sure we have got enough headcount before actually consuming a skb from the batched rx array while transmitting, which is simply done by moving checking the zero headcount a bit ahead. Signed-off-by: Wei Xu <wexu@redhat.com> Reported-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent fa935ca
crypto_engine.c
/*
* Handle async block request by crypto hardware engine.
*
* Copyright (C) 2016 Linaro, Inc.
*
* Author: Baolin Wang <baolin.wang@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <linux/err.h>
#include <linux/delay.h>
#include <crypto/engine.h>
#include <crypto/internal/hash.h>
#include <uapi/linux/sched/types.h>
#include "internal.h"
#define CRYPTO_ENGINE_MAX_QLEN 10
/**
* crypto_pump_requests - dequeue one request from engine queue to process
* @engine: the hardware engine
* @in_kthread: true if we are in the context of the request pump thread
*
* This function checks if there is any request in the engine queue that
* needs processing and if so call out to the driver to initialize hardware
* and handle each request.
*/
static void crypto_pump_requests(struct crypto_engine *engine,
bool in_kthread)
{
struct crypto_async_request *async_req, *backlog;
struct ahash_request *hreq;
struct ablkcipher_request *breq;
unsigned long flags;
bool was_busy = false;
int ret, rtype;
spin_lock_irqsave(&engine->queue_lock, flags);
/* Make sure we are not already running a request */
if (engine->cur_req)
goto out;
/* If another context is idling then defer */
if (engine->idling) {
kthread_queue_work(engine->kworker, &engine->pump_requests);
goto out;
}
/* Check if the engine queue is idle */
if (!crypto_queue_len(&engine->queue) || !engine->running) {
if (!engine->busy)
goto out;
/* Only do teardown in the thread */
if (!in_kthread) {
kthread_queue_work(engine->kworker,
&engine->pump_requests);
goto out;
}
engine->busy = false;
engine->idling = true;
spin_unlock_irqrestore(&engine->queue_lock, flags);
if (engine->unprepare_crypt_hardware &&
engine->unprepare_crypt_hardware(engine))
dev_err(engine->dev, "failed to unprepare crypt hardware\n");
spin_lock_irqsave(&engine->queue_lock, flags);
engine->idling = false;
goto out;
}
/* Get the fist request from the engine queue to handle */
backlog = crypto_get_backlog(&engine->queue);
async_req = crypto_dequeue_request(&engine->queue);
if (!async_req)
goto out;
engine->cur_req = async_req;
if (backlog)
backlog->complete(backlog, -EINPROGRESS);
if (engine->busy)
was_busy = true;
else
engine->busy = true;
spin_unlock_irqrestore(&engine->queue_lock, flags);
rtype = crypto_tfm_alg_type(engine->cur_req->tfm);
/* Until here we get the request need to be encrypted successfully */
if (!was_busy && engine->prepare_crypt_hardware) {
ret = engine->prepare_crypt_hardware(engine);
if (ret) {
dev_err(engine->dev, "failed to prepare crypt hardware\n");
goto req_err;
}
}
switch (rtype) {
case CRYPTO_ALG_TYPE_AHASH:
hreq = ahash_request_cast(engine->cur_req);
if (engine->prepare_hash_request) {
ret = engine->prepare_hash_request(engine, hreq);
if (ret) {
dev_err(engine->dev, "failed to prepare request: %d\n",
ret);
goto req_err;
}
engine->cur_req_prepared = true;
}
ret = engine->hash_one_request(engine, hreq);
if (ret) {
dev_err(engine->dev, "failed to hash one request from queue\n");
goto req_err;
}
return;
case CRYPTO_ALG_TYPE_ABLKCIPHER:
breq = ablkcipher_request_cast(engine->cur_req);
if (engine->prepare_cipher_request) {
ret = engine->prepare_cipher_request(engine, breq);
if (ret) {
dev_err(engine->dev, "failed to prepare request: %d\n",
ret);
goto req_err;
}
engine->cur_req_prepared = true;
}
ret = engine->cipher_one_request(engine, breq);
if (ret) {
dev_err(engine->dev, "failed to cipher one request from queue\n");
goto req_err;
}
return;
default:
dev_err(engine->dev, "failed to prepare request of unknown type\n");
return;
}
req_err:
switch (rtype) {
case CRYPTO_ALG_TYPE_AHASH:
hreq = ahash_request_cast(engine->cur_req);
crypto_finalize_hash_request(engine, hreq, ret);
break;
case CRYPTO_ALG_TYPE_ABLKCIPHER:
breq = ablkcipher_request_cast(engine->cur_req);
crypto_finalize_cipher_request(engine, breq, ret);
break;
}
return;
out:
spin_unlock_irqrestore(&engine->queue_lock, flags);
}
static void crypto_pump_work(struct kthread_work *work)
{
struct crypto_engine *engine =
container_of(work, struct crypto_engine, pump_requests);
crypto_pump_requests(engine, true);
}
/**
* crypto_transfer_cipher_request - transfer the new request into the
* enginequeue
* @engine: the hardware engine
* @req: the request need to be listed into the engine queue
*/
int crypto_transfer_cipher_request(struct crypto_engine *engine,
struct ablkcipher_request *req,
bool need_pump)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&engine->queue_lock, flags);
if (!engine->running) {
spin_unlock_irqrestore(&engine->queue_lock, flags);
return -ESHUTDOWN;
}
ret = ablkcipher_enqueue_request(&engine->queue, req);
if (!engine->busy && need_pump)
kthread_queue_work(engine->kworker, &engine->pump_requests);
spin_unlock_irqrestore(&engine->queue_lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_transfer_cipher_request);
/**
* crypto_transfer_cipher_request_to_engine - transfer one request to list
* into the engine queue
* @engine: the hardware engine
* @req: the request need to be listed into the engine queue
*/
int crypto_transfer_cipher_request_to_engine(struct crypto_engine *engine,
struct ablkcipher_request *req)
{
return crypto_transfer_cipher_request(engine, req, true);
}
EXPORT_SYMBOL_GPL(crypto_transfer_cipher_request_to_engine);
/**
* crypto_transfer_hash_request - transfer the new request into the
* enginequeue
* @engine: the hardware engine
* @req: the request need to be listed into the engine queue
*/
int crypto_transfer_hash_request(struct crypto_engine *engine,
struct ahash_request *req, bool need_pump)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&engine->queue_lock, flags);
if (!engine->running) {
spin_unlock_irqrestore(&engine->queue_lock, flags);
return -ESHUTDOWN;
}
ret = ahash_enqueue_request(&engine->queue, req);
if (!engine->busy && need_pump)
kthread_queue_work(engine->kworker, &engine->pump_requests);
spin_unlock_irqrestore(&engine->queue_lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_transfer_hash_request);
/**
* crypto_transfer_hash_request_to_engine - transfer one request to list
* into the engine queue
* @engine: the hardware engine
* @req: the request need to be listed into the engine queue
*/
int crypto_transfer_hash_request_to_engine(struct crypto_engine *engine,
struct ahash_request *req)
{
return crypto_transfer_hash_request(engine, req, true);
}
EXPORT_SYMBOL_GPL(crypto_transfer_hash_request_to_engine);
/**
* crypto_finalize_cipher_request - finalize one request if the request is done
* @engine: the hardware engine
* @req: the request need to be finalized
* @err: error number
*/
void crypto_finalize_cipher_request(struct crypto_engine *engine,
struct ablkcipher_request *req, int err)
{
unsigned long flags;
bool finalize_cur_req = false;
int ret;
spin_lock_irqsave(&engine->queue_lock, flags);
if (engine->cur_req == &req->base)
finalize_cur_req = true;
spin_unlock_irqrestore(&engine->queue_lock, flags);
if (finalize_cur_req) {
if (engine->cur_req_prepared &&
engine->unprepare_cipher_request) {
ret = engine->unprepare_cipher_request(engine, req);
if (ret)
dev_err(engine->dev, "failed to unprepare request\n");
}
spin_lock_irqsave(&engine->queue_lock, flags);
engine->cur_req = NULL;
engine->cur_req_prepared = false;
spin_unlock_irqrestore(&engine->queue_lock, flags);
}
req->base.complete(&req->base, err);
kthread_queue_work(engine->kworker, &engine->pump_requests);
}
EXPORT_SYMBOL_GPL(crypto_finalize_cipher_request);
/**
* crypto_finalize_hash_request - finalize one request if the request is done
* @engine: the hardware engine
* @req: the request need to be finalized
* @err: error number
*/
void crypto_finalize_hash_request(struct crypto_engine *engine,
struct ahash_request *req, int err)
{
unsigned long flags;
bool finalize_cur_req = false;
int ret;
spin_lock_irqsave(&engine->queue_lock, flags);
if (engine->cur_req == &req->base)
finalize_cur_req = true;
spin_unlock_irqrestore(&engine->queue_lock, flags);
if (finalize_cur_req) {
if (engine->cur_req_prepared &&
engine->unprepare_hash_request) {
ret = engine->unprepare_hash_request(engine, req);
if (ret)
dev_err(engine->dev, "failed to unprepare request\n");
}
spin_lock_irqsave(&engine->queue_lock, flags);
engine->cur_req = NULL;
engine->cur_req_prepared = false;
spin_unlock_irqrestore(&engine->queue_lock, flags);
}
req->base.complete(&req->base, err);
kthread_queue_work(engine->kworker, &engine->pump_requests);
}
EXPORT_SYMBOL_GPL(crypto_finalize_hash_request);
/**
* crypto_engine_start - start the hardware engine
* @engine: the hardware engine need to be started
*
* Return 0 on success, else on fail.
*/
int crypto_engine_start(struct crypto_engine *engine)
{
unsigned long flags;
spin_lock_irqsave(&engine->queue_lock, flags);
if (engine->running || engine->busy) {
spin_unlock_irqrestore(&engine->queue_lock, flags);
return -EBUSY;
}
engine->running = true;
spin_unlock_irqrestore(&engine->queue_lock, flags);
kthread_queue_work(engine->kworker, &engine->pump_requests);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_engine_start);
/**
* crypto_engine_stop - stop the hardware engine
* @engine: the hardware engine need to be stopped
*
* Return 0 on success, else on fail.
*/
int crypto_engine_stop(struct crypto_engine *engine)
{
unsigned long flags;
unsigned int limit = 500;
int ret = 0;
spin_lock_irqsave(&engine->queue_lock, flags);
/*
* If the engine queue is not empty or the engine is on busy state,
* we need to wait for a while to pump the requests of engine queue.
*/
while ((crypto_queue_len(&engine->queue) || engine->busy) && limit--) {
spin_unlock_irqrestore(&engine->queue_lock, flags);
msleep(20);
spin_lock_irqsave(&engine->queue_lock, flags);
}
if (crypto_queue_len(&engine->queue) || engine->busy)
ret = -EBUSY;
else
engine->running = false;
spin_unlock_irqrestore(&engine->queue_lock, flags);
if (ret)
dev_warn(engine->dev, "could not stop engine\n");
return ret;
}
EXPORT_SYMBOL_GPL(crypto_engine_stop);
/**
* crypto_engine_alloc_init - allocate crypto hardware engine structure and
* initialize it.
* @dev: the device attached with one hardware engine
* @rt: whether this queue is set to run as a realtime task
*
* This must be called from context that can sleep.
* Return: the crypto engine structure on success, else NULL.
*/
struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
{
struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
struct crypto_engine *engine;
if (!dev)
return NULL;
engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL);
if (!engine)
return NULL;
engine->dev = dev;
engine->rt = rt;
engine->running = false;
engine->busy = false;
engine->idling = false;
engine->cur_req_prepared = false;
engine->priv_data = dev;
snprintf(engine->name, sizeof(engine->name),
"%s-engine", dev_name(dev));
crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_QLEN);
spin_lock_init(&engine->queue_lock);
engine->kworker = kthread_create_worker(0, "%s", engine->name);
if (IS_ERR(engine->kworker)) {
dev_err(dev, "failed to create crypto request pump task\n");
return NULL;
}
kthread_init_work(&engine->pump_requests, crypto_pump_work);
if (engine->rt) {
dev_info(dev, "will run requests pump with realtime priority\n");
sched_setscheduler(engine->kworker->task, SCHED_FIFO, ¶m);
}
return engine;
}
EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);
/**
* crypto_engine_exit - free the resources of hardware engine when exit
* @engine: the hardware engine need to be freed
*
* Return 0 for success.
*/
int crypto_engine_exit(struct crypto_engine *engine)
{
int ret;
ret = crypto_engine_stop(engine);
if (ret)
return ret;
kthread_destroy_worker(engine->kworker);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_engine_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Crypto hardware engine framework");
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