// SPDX-License-Identifier: GPL-2.0-only/* Copyright (C) 2009 Red Hat, Inc. * Author: Michael S. Tsirkin <mst@redhat.com> * * test virtio server in host kernel. */ #include <linux/compat.h>#include <linux/eventfd.h>#include <linux/vhost.h>#include <linux/miscdevice.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/workqueue.h>#include <linux/file.h>#include <linux/slab.h> #include "test.h"#include "vhost.h" /* Max number of bytes transferred before requeueing the job. * Using this limit prevents one virtqueue from starving others. */#define VHOST_TEST_WEIGHT 0x80000 /* Max number of packets transferred before requeueing the job. * Using this limit prevents one virtqueue from starving others with * pkts. */#define VHOST_TEST_PKT_WEIGHT 256 static const int vhost_test_bits[] = {	VHOST_FEATURES}; #define VHOST_TEST_FEATURES VHOST_FEATURES_U64(vhost_test_bits, 0) enum {	VHOST_TEST_VQ = 0,	VHOST_TEST_VQ_MAX = 1,}; struct vhost_test {	struct vhost_dev dev;	struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];}; /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */static void handle_vq(struct vhost_test *n){	struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];	unsigned out, in;	int head;	size_t len, total_len = 0;	void *private; 	mutex_lock(&vq->mutex);	private = vhost_vq_get_backend(vq);	if (!private) {		mutex_unlock(&vq->mutex);		return;	} 	vhost_disable_notify(&n->dev, vq); 	for (;;) {		head = vhost_get_vq_desc(vq, vq->iov,					 ARRAY_SIZE(vq->iov),					 &out, &in,					 NULL, NULL);		/* On error, stop handling until the next kick. */		if (unlikely(head < 0))			break;		/* Nothing new?  Wait for eventfd to tell us they refilled. */		if (head == vq->num) {			if (unlikely(vhost_enable_notify(&n->dev, vq))) {				vhost_disable_notify(&n->dev, vq);				continue;			}			break;		}		if (in) {			vq_err(vq, "Unexpected descriptor format for TX: "			       "out %d, int %d\n", out, in);			break;		}		len = iov_length(vq->iov, out);		/* Sanity check */		if (!len) {			vq_err(vq, "Unexpected 0 len for TX\n");			break;		}		vhost_add_used_and_signal(&n->dev, vq, head, 0);		total_len += len;		if (unlikely(vhost_exceeds_weight(vq, 0, total_len)))			break;	} 	mutex_unlock(&vq->mutex);} static void handle_vq_kick(struct vhost_work *work){	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,						  poll.work);	struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev); 	handle_vq(n);} static int vhost_test_open(struct inode *inode, struct file *f){	struct vhost_test *n = kmalloc_obj(*n);	struct vhost_dev *dev;	struct vhost_virtqueue **vqs; 	if (!n)		return -ENOMEM;	vqs = kmalloc_objs(*vqs, VHOST_TEST_VQ_MAX);	if (!vqs) {		kfree(n);		return -ENOMEM;	} 	dev = &n->dev;	vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;	vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,		       VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT, true, NULL); 	f->private_data = n; 	return 0;} static void *vhost_test_stop_vq(struct vhost_test *n,				struct vhost_virtqueue *vq){	void *private; 	mutex_lock(&vq->mutex);	private = vhost_vq_get_backend(vq);	vhost_vq_set_backend(vq, NULL);	mutex_unlock(&vq->mutex);	return private;} static void vhost_test_stop(struct vhost_test *n, void **privatep){	*privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);} static void vhost_test_flush(struct vhost_test *n){	vhost_dev_flush(&n->dev);} static int vhost_test_release(struct inode *inode, struct file *f){	struct vhost_test *n = f->private_data;	void  *private; 	vhost_test_stop(n, &private);	vhost_test_flush(n);	vhost_dev_stop(&n->dev);	vhost_dev_cleanup(&n->dev);	kfree(n->dev.vqs);	kfree(n);	return 0;} static long vhost_test_run(struct vhost_test *n, int test){	void *priv, *oldpriv;	struct vhost_virtqueue *vq;	int r, index; 	if (test < 0 || test > 1)		return -EINVAL; 	mutex_lock(&n->dev.mutex);	r = vhost_dev_check_owner(&n->dev);	if (r)		goto err; 	for (index = 0; index < n->dev.nvqs; ++index) {		/* Verify that ring has been setup correctly. */		if (!vhost_vq_access_ok(&n->vqs[index])) {			r = -EFAULT;			goto err;		}	} 	for (index = 0; index < n->dev.nvqs; ++index) {		vq = n->vqs + index;		mutex_lock(&vq->mutex);		priv = test ? n : NULL; 		/* start polling new socket */		oldpriv = vhost_vq_get_backend(vq);		vhost_vq_set_backend(vq, priv); 		r = vhost_vq_init_access(&n->vqs[index]); 		mutex_unlock(&vq->mutex); 		if (r)			goto err; 		if (oldpriv) {			vhost_test_flush(n);		}	} 	mutex_unlock(&n->dev.mutex);	return 0; err:	mutex_unlock(&n->dev.mutex);	return r;} static long vhost_test_reset_owner(struct vhost_test *n){	void *priv = NULL;	long err;	struct vhost_iotlb *umem; 	mutex_lock(&n->dev.mutex);	err = vhost_dev_check_owner(&n->dev);	if (err)		goto done;	umem = vhost_dev_reset_owner_prepare();	if (!umem) {		err = -ENOMEM;		goto done;	}	vhost_test_stop(n, &priv);	vhost_test_flush(n);	vhost_dev_stop(&n->dev);	vhost_dev_reset_owner(&n->dev, umem);done:	mutex_unlock(&n->dev.mutex);	return err;} static int vhost_test_set_features(struct vhost_test *n, u64 features){	struct vhost_virtqueue *vq; 	mutex_lock(&n->dev.mutex);	if ((features & (1 << VHOST_F_LOG_ALL)) &&	    !vhost_log_access_ok(&n->dev)) {		mutex_unlock(&n->dev.mutex);		return -EFAULT;	}	vq = &n->vqs[VHOST_TEST_VQ];	mutex_lock(&vq->mutex);	vq->acked_features = features;	mutex_unlock(&vq->mutex);	mutex_unlock(&n->dev.mutex);	return 0;} static long vhost_test_set_backend(struct vhost_test *n, unsigned index, int fd){	static void *backend; 	const bool enable = fd != -1;	struct vhost_virtqueue *vq;	int r; 	mutex_lock(&n->dev.mutex);	r = vhost_dev_check_owner(&n->dev);	if (r)		goto err; 	if (index >= VHOST_TEST_VQ_MAX) {		r = -ENOBUFS;		goto err;	}	vq = &n->vqs[index];	mutex_lock(&vq->mutex); 	/* Verify that ring has been setup correctly. */	if (!vhost_vq_access_ok(vq)) {		r = -EFAULT;		goto err_vq;	}	if (!enable) {		vhost_poll_stop(&vq->poll);		backend = vhost_vq_get_backend(vq);		vhost_vq_set_backend(vq, NULL);	} else {		vhost_vq_set_backend(vq, backend);		r = vhost_vq_init_access(vq);		if (r == 0)			r = vhost_poll_start(&vq->poll, vq->kick);	} 	mutex_unlock(&vq->mutex); 	if (enable) {		vhost_test_flush(n);	} 	mutex_unlock(&n->dev.mutex);	return 0; err_vq:	mutex_unlock(&vq->mutex);err:	mutex_unlock(&n->dev.mutex);	return r;} static long vhost_test_ioctl(struct file *f, unsigned int ioctl,			     unsigned long arg){	struct vhost_vring_file backend;	struct vhost_test *n = f->private_data;	void __user *argp = (void __user *)arg;	u64 __user *featurep = argp;	int test;	u64 features;	int r;	switch (ioctl) {	case VHOST_TEST_RUN:		if (copy_from_user(&test, argp, sizeof test))			return -EFAULT;		return vhost_test_run(n, test);	case VHOST_TEST_SET_BACKEND:		if (copy_from_user(&backend, argp, sizeof backend))			return -EFAULT;		return vhost_test_set_backend(n, backend.index, backend.fd);	case VHOST_GET_FEATURES:		features = VHOST_TEST_FEATURES;		if (copy_to_user(featurep, &features, sizeof features))			return -EFAULT;		return 0;	case VHOST_SET_FEATURES:		if (copy_from_user(&features, featurep, sizeof features))			return -EFAULT;		if (features & ~VHOST_TEST_FEATURES)			return -EOPNOTSUPP;		return vhost_test_set_features(n, features);	case VHOST_RESET_OWNER:		return vhost_test_reset_owner(n);	default:		mutex_lock(&n->dev.mutex);		r = vhost_dev_ioctl(&n->dev, ioctl, argp);                if (r == -ENOIOCTLCMD)                        r = vhost_vring_ioctl(&n->dev, ioctl, argp);		vhost_test_flush(n);		mutex_unlock(&n->dev.mutex);		return r;	}} static const struct file_operations vhost_test_fops = {	.owner          = THIS_MODULE,	.release        = vhost_test_release,	.unlocked_ioctl = vhost_test_ioctl,	.compat_ioctl   = compat_ptr_ioctl,	.open           = vhost_test_open,	.llseek		= noop_llseek,}; static struct miscdevice vhost_test_misc = {	MISC_DYNAMIC_MINOR,	"vhost-test",	&vhost_test_fops,};module_misc_device(vhost_test_misc); MODULE_VERSION("0.0.1");MODULE_LICENSE("GPL v2");MODULE_AUTHOR("Michael S. Tsirkin");MODULE_DESCRIPTION("Host kernel side for virtio simulator");