From 71ccc212e5b28dfcc870b6db6589c2df264fdc6a Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 29 Nov 2010 19:09:01 +0200 Subject: vhost test module This adds a test module for vhost infrastructure. Intentionally not tied to kbuild to prevent people from installing and loading it accidentally. Signed-off-by: Michael S. Tsirkin --- drivers/vhost/test.c | 320 +++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/vhost/test.h | 7 ++ 2 files changed, 327 insertions(+) create mode 100644 drivers/vhost/test.c create mode 100644 drivers/vhost/test.h (limited to 'drivers/vhost') diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c new file mode 100644 index 0000000..099f302 --- /dev/null +++ b/drivers/vhost/test.c @@ -0,0 +1,320 @@ +/* Copyright (C) 2009 Red Hat, Inc. + * Author: Michael S. Tsirkin + * + * This work is licensed under the terms of the GNU GPL, version 2. + * + * test virtio server in host kernel. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "test.h" +#include "vhost.c" + +/* Max number of bytes transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others. */ +#define VHOST_TEST_WEIGHT 0x80000 + +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->dev.vqs[VHOST_TEST_VQ]; + unsigned out, in; + int head; + size_t len, total_len = 0; + void *private; + + private = rcu_dereference_check(vq->private_data, 1); + if (!private) + return; + + mutex_lock(&vq->mutex); + vhost_disable_notify(vq); + + for (;;) { + head = vhost_get_vq_desc(&n->dev, 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(vq))) { + vhost_disable_notify(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(total_len >= VHOST_TEST_WEIGHT)) { + vhost_poll_queue(&vq->poll); + 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(sizeof *n, GFP_KERNEL); + struct vhost_dev *dev; + int r; + + if (!n) + return -ENOMEM; + + dev = &n->dev; + n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick; + r = vhost_dev_init(dev, n->vqs, VHOST_TEST_VQ_MAX); + if (r < 0) { + kfree(n); + return r; + } + + 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 = rcu_dereference_protected(vq->private_data, + lockdep_is_held(&vq->mutex)); + rcu_assign_pointer(vq->private_data, 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_vq(struct vhost_test *n, int index) +{ + vhost_poll_flush(&n->dev.vqs[index].poll); +} + +static void vhost_test_flush(struct vhost_test *n) +{ + vhost_test_flush_vq(n, VHOST_TEST_VQ); +} + +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_cleanup(&n->dev); + /* We do an extra flush before freeing memory, + * since jobs can re-queue themselves. */ + vhost_test_flush(n); + 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 = rcu_dereference_protected(vq->private_data, + lockdep_is_held(&vq->mutex)); + rcu_assign_pointer(vq->private_data, priv); + + mutex_unlock(&vq->mutex); + + if (oldpriv) { + vhost_test_flush_vq(n, index); + } + } + + 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; + mutex_lock(&n->dev.mutex); + err = vhost_dev_check_owner(&n->dev); + if (err) + goto done; + vhost_test_stop(n, &priv); + vhost_test_flush(n); + err = vhost_dev_reset_owner(&n->dev); +done: + mutex_unlock(&n->dev.mutex); + return err; +} + +static int vhost_test_set_features(struct vhost_test *n, u64 features) +{ + 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; + } + n->dev.acked_features = features; + smp_wmb(); + vhost_test_flush(n); + mutex_unlock(&n->dev.mutex); + return 0; +} + +static long vhost_test_ioctl(struct file *f, unsigned int ioctl, + unsigned long arg) +{ + 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_GET_FEATURES: + features = VHOST_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_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, arg); + vhost_test_flush(n); + mutex_unlock(&n->dev.mutex); + return r; + } +} + +#ifdef CONFIG_COMPAT +static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl, + unsigned long arg) +{ + return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); +} +#endif + +static const struct file_operations vhost_test_fops = { + .owner = THIS_MODULE, + .release = vhost_test_release, + .unlocked_ioctl = vhost_test_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = vhost_test_compat_ioctl, +#endif + .open = vhost_test_open, + .llseek = noop_llseek, +}; + +static struct miscdevice vhost_test_misc = { + MISC_DYNAMIC_MINOR, + "vhost-test", + &vhost_test_fops, +}; + +static int vhost_test_init(void) +{ + return misc_register(&vhost_test_misc); +} +module_init(vhost_test_init); + +static void vhost_test_exit(void) +{ + misc_deregister(&vhost_test_misc); +} +module_exit(vhost_test_exit); + +MODULE_VERSION("0.0.1"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Michael S. Tsirkin"); +MODULE_DESCRIPTION("Host kernel side for virtio simulator"); diff --git a/drivers/vhost/test.h b/drivers/vhost/test.h new file mode 100644 index 0000000..1fef5df --- /dev/null +++ b/drivers/vhost/test.h @@ -0,0 +1,7 @@ +#ifndef LINUX_VHOST_TEST_H +#define LINUX_VHOST_TEST_H + +/* Start a given test on the virtio null device. 0 stops all tests. */ +#define VHOST_TEST_RUN _IOW(VHOST_VIRTIO, 0x31, int) + +#endif -- cgit v1.1