[PATCH v2 10/12] [RESEND] vhost: add an SOF DSP driver
Guennadi Liakhovetski
guennadi.liakhovetski at linux.intel.com
Fri Apr 3 11:14:04 CEST 2020
The SOF DSP vhost driver consists of two parts: a sound and a vhost
part. This patch implements the vhost part of the driver. It handles
QEMU communication with the vhost misc device and virtual queues to
any VirtIO guests.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski at linux.intel.com>
---
drivers/vhost/Kconfig | 7 +
drivers/vhost/Makefile | 5 +
drivers/vhost/dsp.c | 728 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 740 insertions(+)
create mode 100644 drivers/vhost/dsp.c
diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index 3d03ccb..b9f3071 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -34,6 +34,13 @@ config VHOST_VSOCK
To compile this driver as a module, choose M here: the module will be called
vhost_vsock.
+config VHOST_SOF
+ bool "Vhost SOF driver"
+ default n
+ ---help---
+ SOF vhost VirtIO driver. It exports the same IPC interface, as the
+ one, used for DSP communication, to Linux VirtIO guests.
+
config VHOST
tristate
---help---
diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
index 6c6df24..1914561 100644
--- a/drivers/vhost/Makefile
+++ b/drivers/vhost/Makefile
@@ -10,4 +10,9 @@ vhost_vsock-y := vsock.o
obj-$(CONFIG_VHOST_RING) += vringh.o
+ifdef CONFIG_VHOST_SOF
+obj-$(CONFIG_SND_SOC_SOF) += vhost_sof.o
+vhost_sof-y := dsp.o
+endif
+
obj-$(CONFIG_VHOST) += vhost.o
diff --git a/drivers/vhost/dsp.c b/drivers/vhost/dsp.c
new file mode 100644
index 00000000..205ae8c
--- /dev/null
+++ b/drivers/vhost/dsp.c
@@ -0,0 +1,728 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * Copyright(c) 2019-2020 Intel Corporation. All rights reserved.
+ *
+ * Author: Guennadi Liakhovetski <guennadi.liakhovetski at linux.intel.com>
+ *
+ * vhost-SOF VirtIO interface
+ */
+
+#include <linux/bitmap.h>
+#include <linux/compat.h>
+#include <linux/file.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vhost.h>
+#include <linux/workqueue.h>
+
+#include <sound/sof/stream.h>
+#include <sound/sof/virtio.h>
+
+#include "vhost.h"
+
+#define VHOST_DSP_FEATURES VHOST_FEATURES
+#define VHOST_DSP_BATCH 64
+#define VHOST_DSP_WEIGHT 0x80000
+#define VHOST_DSP_PKT_WEIGHT 256
+
+struct vhost_dsp_virtqueue {
+ struct vhost_virtqueue vq;
+};
+
+struct snd_sof_dev;
+
+struct dsp_sof_client;
+struct vhost_dsp {
+ struct vhost_dev dev;
+ struct vhost_dsp_virtqueue vqs[SOF_VIRTIO_NUM_OF_VQS];
+ struct vhost_work work;
+ struct vhost_virtqueue *vq_p[SOF_VIRTIO_NUM_OF_VQS];
+
+ bool active;
+
+ spinlock_t posn_lock; /* Protects posn_list */
+ struct list_head posn_list;
+ struct list_head posn_buf_list;
+
+ u8 ipc_buf[SOF_IPC_MSG_MAX_SIZE];
+ u8 reply_buf[SOF_IPC_MSG_MAX_SIZE];
+
+ union {
+ struct dsp_sof_data_req data_req;
+ struct dsp_sof_data_resp data_resp;
+ };
+
+ struct dsp_sof_client *snd;
+};
+
+/* A stream position message, waiting to be sent to a guest */
+struct vhost_dsp_posn {
+ struct list_head list;
+ struct sof_ipc_stream_posn posn;
+};
+
+/* A guest buffer, waiting to be filled with a stream position message */
+struct vhost_dsp_iovec {
+ struct list_head list;
+ int head;
+};
+
+/* A guest is booting */
+static int vhost_dsp_activate(struct vhost_dsp *dsp)
+{
+ unsigned int i;
+ int ret = 0;
+
+ mutex_lock(&dsp->dev.mutex);
+
+ /* Wait until all the VirtQueues have been initialised */
+ if (!dsp->active) {
+ for (i = 0; i < ARRAY_SIZE(dsp->vqs); i++) {
+ struct vhost_virtqueue *vq = &dsp->vqs[i].vq;
+
+ /* .private_data is required != NULL */
+ vq->private_data = dsp->vqs + i;
+ /* needed for re-initialisation upon guest reboot */
+ ret = vhost_vq_init_access(vq);
+ if (ret)
+ vq_err(vq,
+ "%s(): error %d initialising vq #%d\n",
+ __func__, ret, i);
+ }
+ if (!ret)
+ dsp->active = true;
+ }
+
+ mutex_unlock(&dsp->dev.mutex);
+
+ return ret;
+}
+
+/* A guest is powered off or reset */
+static void vhost_dsp_deactivate(struct vhost_dsp *dsp)
+{
+ unsigned int i;
+
+ mutex_lock(&dsp->dev.mutex);
+
+ if (dsp->active) {
+ struct vhost_dsp_iovec *buf, *next;
+ unsigned long flags;
+
+ dsp->active = false;
+
+ spin_lock_irqsave(&dsp->posn_lock, flags);
+ list_for_each_entry_safe(buf, next, &dsp->posn_buf_list, list) {
+ list_del(&buf->list);
+ kfree(buf);
+ }
+ spin_unlock_irqrestore(&dsp->posn_lock, flags);
+
+ /* signal, that we're inactive */
+ for (i = 0; i < ARRAY_SIZE(dsp->vqs); i++)
+ dsp->vqs[i].vq.private_data = NULL;
+ }
+
+ mutex_unlock(&dsp->dev.mutex);
+}
+
+/* No special features at the moment */
+static int vhost_dsp_set_features(struct vhost_dsp *dsp, u64 features)
+{
+ struct vhost_virtqueue *vq;
+ unsigned int i;
+
+ if (features & ~VHOST_DSP_FEATURES)
+ return -EOPNOTSUPP;
+
+ mutex_lock(&dsp->dev.mutex);
+
+ if ((features & (1 << VHOST_F_LOG_ALL)) &&
+ !vhost_log_access_ok(&dsp->dev)) {
+ mutex_unlock(&dsp->dev.mutex);
+ return -EFAULT;
+ }
+
+ for (i = 0; i < SOF_VIRTIO_NUM_OF_VQS; i++) {
+ vq = &dsp->vqs[i].vq;
+
+ mutex_lock(&vq->mutex);
+ vq->acked_features = features;
+ mutex_unlock(&vq->mutex);
+ }
+
+ mutex_unlock(&dsp->dev.mutex);
+
+ return 0;
+}
+
+/* .ioctl(): we only use VHOST_SET_RUNNING in a not-default way */
+static long vhost_dsp_ioctl(struct file *filp, unsigned int ioctl,
+ unsigned long arg)
+{
+ struct vhost_dsp *dsp = filp->private_data;
+ void __user *argp = (void __user *)arg;
+ struct vhost_dsp_topology tplg;
+ u64 __user *featurep = argp;
+ u64 features;
+ int start;
+ long ret;
+
+ switch (ioctl) {
+ case VHOST_GET_FEATURES:
+ features = VHOST_DSP_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;
+ return vhost_dsp_set_features(dsp, features);
+ case VHOST_GET_BACKEND_FEATURES:
+ features = 0;
+ if (copy_to_user(featurep, &features, sizeof(features)))
+ return -EFAULT;
+ return 0;
+ case VHOST_SET_BACKEND_FEATURES:
+ if (copy_from_user(&features, featurep, sizeof(features)))
+ return -EFAULT;
+ if (features)
+ return -EOPNOTSUPP;
+ return 0;
+ case VHOST_RESET_OWNER:
+ mutex_lock(&dsp->dev.mutex);
+ ret = vhost_dev_check_owner(&dsp->dev);
+ if (!ret) {
+ struct vhost_umem *umem = vhost_dev_reset_owner_prepare();
+ if (!umem) {
+ ret = -ENOMEM;
+ } else {
+ vhost_dev_stop(&dsp->dev);
+ vhost_dev_reset_owner(&dsp->dev, umem);
+ }
+ }
+ mutex_unlock(&dsp->dev.mutex);
+ return ret;
+ case VHOST_SET_OWNER:
+ mutex_lock(&dsp->dev.mutex);
+ ret = vhost_dev_set_owner(&dsp->dev);
+ mutex_unlock(&dsp->dev.mutex);
+ return ret;
+ case VHOST_SET_RUNNING:
+ if (copy_from_user(&start, argp, sizeof(start)))
+ return -EFAULT;
+
+ if (start)
+ return vhost_dsp_activate(dsp);
+
+ vhost_dsp_deactivate(dsp);
+ return 0;
+ case VHOST_DSP_SET_GUEST_TPLG:
+ if (copy_from_user(&tplg, argp, sizeof(tplg)))
+ return -EFAULT;
+ return dsp_sof_set_tplg(dsp->snd, &tplg);
+ }
+
+ mutex_lock(&dsp->dev.mutex);
+ ret = vhost_dev_ioctl(&dsp->dev, ioctl, argp);
+ if (ret == -ENOIOCTLCMD)
+ ret = vhost_vring_ioctl(&dsp->dev, ioctl, argp);
+ mutex_unlock(&dsp->dev.mutex);
+
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static long vhost_dsp_compat_ioctl(struct file *filp, unsigned int ioctl,
+ unsigned long arg)
+{
+ return vhost_dsp_ioctl(filp, ioctl, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static ssize_t vhost_dsp_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *filp = iocb->ki_filp;
+ struct vhost_dsp *dsp = filp->private_data;
+ struct vhost_dev *dev = &dsp->dev;
+ int noblock = filp->f_flags & O_NONBLOCK;
+
+ return vhost_chr_read_iter(dev, to, noblock);
+}
+
+static ssize_t vhost_dsp_chr_write_iter(struct kiocb *iocb,
+ struct iov_iter *from)
+{
+ struct file *filp = iocb->ki_filp;
+ struct vhost_dsp *dsp = filp->private_data;
+ struct vhost_dev *dev = &dsp->dev;
+
+ return vhost_chr_write_iter(dev, from);
+}
+
+static __poll_t vhost_dsp_chr_poll(struct file *filp, poll_table *wait)
+{
+ struct vhost_dsp *dsp = filp->private_data;
+ struct vhost_dev *dev = &dsp->dev;
+
+ return vhost_chr_poll(filp, dev, wait);
+}
+
+/* IPC message from a guest */
+static void handle_ipc_cmd_kick(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_dsp *dsp = container_of(vq->dev, struct vhost_dsp, dev);
+ int vq_idx = SOF_VIRTIO_IPC_CMD_VQ;
+ size_t total_len = 0;
+
+ /* IPC message from the guest */
+ mutex_lock(&vq->mutex);
+
+ /* notifications must be disabled while handling the queue */
+ vhost_disable_notify(&dsp->dev, vq);
+
+ for (;;) {
+ struct iov_iter iov_iter;
+ size_t len, nbytes;
+ unsigned int out, in, i;
+ size_t iov_offset, iov_count;
+ /* IPC command from FE to DSP */
+ int head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+ &out, &in, NULL, NULL), ret;
+ if (head < 0)
+ break;
+
+ /* Nothing new? Wait for eventfd to tell us they refilled. */
+ if (head == vq->num) {
+ if (unlikely(vhost_enable_notify(&dsp->dev, vq))) {
+ vhost_disable_notify(&dsp->dev, vq);
+ continue;
+ }
+ break;
+ }
+
+ if (in != out)
+ /* We expect in == out and usually == 1 */
+ continue;
+
+ iov_offset = out;
+ iov_count = out;
+
+ for (i = 0; i < iov_count; i++) {
+ struct sof_ipc_reply *rhdr = (struct sof_ipc_reply *)dsp->reply_buf;
+ size_t to_copy;
+
+ len = vq->iov[i].iov_len;
+
+ if (len > sizeof(dsp->ipc_buf)) {
+ vq_err(vq,
+ "%s(): head %d out %d in %d len %zd\n",
+ __func__, head, out, in, len);
+ continue;
+ }
+
+ total_len += len;
+
+ iov_iter_init(&iov_iter, WRITE, vq->iov + i, 1, len);
+
+ nbytes = copy_from_iter(dsp->ipc_buf, len, &iov_iter);
+ if (nbytes != len) {
+ vq_err(vq, "Expected %zu bytes for IPC, got %zu bytes\n",
+ len, nbytes);
+ continue;
+ }
+
+ /* Process the IPC payload */
+ ret = dsp_sof_ipc_fwd(dsp->snd, vq_idx, dsp->ipc_buf,
+ dsp->reply_buf, len,
+ vq->iov[iov_offset + i].iov_len);
+ if (ret < 0) {
+ struct sof_ipc_cmd_hdr *hdr =
+ (struct sof_ipc_cmd_hdr *)dsp->ipc_buf;
+ vq_err(vq,
+ "%s(): IPC 0x%x failed with error %d\n",
+ __func__, hdr->cmd, ret);
+ }
+
+ to_copy = min_t(size_t, sizeof(dsp->reply_buf),
+ rhdr->hdr.size);
+
+ iov_iter_init(&iov_iter, READ, vq->iov + iov_offset + i,
+ 1, to_copy);
+ if (copy_to_iter(dsp->reply_buf, to_copy, &iov_iter) > 0)
+ /* Return any response */
+ vhost_add_used_and_signal(vq->dev, vq, head, to_copy);
+ }
+ }
+
+ mutex_unlock(&vq->mutex);
+}
+
+/* Try to send a position update buffer to the guest */
+static void vhost_dsp_fill_posn_vqbuf(struct vhost_dsp *dsp)
+{
+ struct vhost_virtqueue *vq = &dsp->vqs[SOF_VIRTIO_POSN_VQ].vq;
+ struct iov_iter iov_iter;
+ struct vhost_dsp_iovec *buf;
+ struct vhost_dsp_posn *entry;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dsp->posn_lock, flags);
+
+ if (list_empty(&dsp->posn_list)) {
+ /*
+ * This is the normal path, when called from
+ * handle_posn_kick(): usually at that time we don't have a
+ * position update waiting yet
+ */
+ spin_unlock_irqrestore(&dsp->posn_lock, flags);
+ return;
+ }
+
+ if (list_empty(&dsp->posn_buf_list)) {
+ vq_err(vq, "%s(): no vq descriptors\n", __func__);
+ spin_unlock_irqrestore(&dsp->posn_lock, flags);
+ return;
+ }
+
+ buf = list_first_entry(&dsp->posn_buf_list,
+ struct vhost_dsp_iovec, list);
+ list_del(&buf->list);
+
+ entry = list_first_entry(&dsp->posn_list,
+ struct vhost_dsp_posn, list);
+ list_del(&entry->list);
+
+ spin_unlock_irqrestore(&dsp->posn_lock, flags);
+
+ /* Take the lock and send the buffer */
+ mutex_lock(&vq->mutex);
+ iov_iter_init(&iov_iter, READ, vq->iov, 1, sizeof(entry->posn));
+ if (copy_to_iter(&entry->posn, sizeof(entry->posn), &iov_iter) > 0)
+ /*
+ * Actually the last parameter for vhost_add_used_and_signal()
+ * should be "sizeof(*posn)," but that didn't work
+ */
+ vhost_add_used_and_signal(vq->dev, vq, buf->head, 0);
+ mutex_unlock(&vq->mutex);
+
+ kfree(buf);
+ kfree(entry);
+}
+
+/* Handle kick on the data VirtQ */
+static void handle_data_kick(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_dsp *dsp = container_of(vq->dev, struct vhost_dsp, dev);
+
+ mutex_lock(&vq->mutex);
+
+ vhost_disable_notify(&dsp->dev, vq);
+
+ for (;;) {
+ struct iov_iter iov_iter;
+ unsigned int out, in, i;
+ int head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+ &out, &in, NULL, NULL);
+ if (head < 0)
+ break;
+
+ /* Nothing new? Wait for eventfd to tell us they refilled. */
+ if (head == vq->num) {
+ if (unlikely(vhost_enable_notify(&dsp->dev, vq))) {
+ vhost_disable_notify(&dsp->dev, vq);
+ continue;
+ }
+ break;
+ }
+
+ if (in != out)
+ /* We expect in == out and usually == 1 */
+ continue;
+
+ for (i = 0; i < out; i++) {
+ u8 _req[HDR_SIZE_REQ];
+ u8 _resp[HDR_SIZE_RESP];
+ struct dsp_sof_data_resp *resp;
+ struct dsp_sof_data_req *req;
+ size_t to_copy, nbytes, len = vq->iov[i].iov_len;
+ int ret;
+
+ if (len > sizeof(dsp->data_req) || len < HDR_SIZE_REQ) {
+ vq_err(vq,
+ "%s(): head %d out %d in %d len %zd\n",
+ __func__, head, out, in, len);
+ continue;
+ }
+
+ iov_iter_init(&iov_iter, WRITE, vq->iov + i, 1, len);
+
+ if (len > HDR_SIZE_REQ) {
+ /* playback */
+ req = &dsp->data_req;
+ resp = (struct dsp_sof_data_resp *)_resp;
+ } else {
+ /* capture */
+ req = (struct dsp_sof_data_req *)_req;
+ resp = &dsp->data_resp;
+ }
+
+ nbytes = copy_from_iter(req, len, &iov_iter);
+ if (nbytes != len) {
+ vq_err(vq, "Expected %zu bytes for IPC, got %zu bytes\n",
+ len, nbytes);
+ continue;
+ }
+
+ /* Copy data to or from the audio buffer */
+ ret = dsp_sof_stream_data(dsp->snd, req, resp);
+ if (ret < 0) {
+ vq_err(vq, "Error %d copying data\n", ret);
+ continue;
+ }
+
+ to_copy = resp->size + HDR_SIZE_RESP;
+
+ iov_iter_init(&iov_iter, READ, vq->iov + out + i,
+ 1, to_copy);
+ if (copy_to_iter(resp, to_copy, &iov_iter) > 0)
+ vhost_add_used_and_signal(vq->dev, vq, head, to_copy);
+ }
+ }
+
+ mutex_unlock(&vq->mutex);
+}
+
+/* A new position update buffer from the guest */
+static void handle_posn_kick(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_dsp *dsp = container_of(vq->dev, struct vhost_dsp, dev);
+ struct vhost_dsp_iovec *buf;
+ unsigned int out, in;
+ unsigned long flags;
+ bool free = true, enable = true;
+
+ /* Queue the buffer for future position updates from the DSP */
+ buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return;
+
+ mutex_lock(&vq->mutex);
+
+ vhost_disable_notify(&dsp->dev, vq);
+
+ for (;;) {
+ /* A posn descriptor should have 1 "in" and 0 "out" buffers */
+ buf->head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+ &out, &in, NULL, NULL);
+
+ if (buf->head < 0) {
+ vq_err(vq, "%s(): no vq descriptors: %d\n",
+ __func__, buf->head);
+ break;
+ }
+
+ if (buf->head == vq->num) {
+ if (unlikely(vhost_enable_notify(&dsp->dev, vq))) {
+ vhost_disable_notify(&dsp->dev, vq);
+ continue;
+ }
+ enable = false;
+ break;
+ }
+
+ if (unlikely(out))
+ vq_err(vq,
+ "%s(): position update has %d outgoing buffers!\n",
+ __func__, out);
+
+ if (unlikely(vq->iov[out].iov_len !=
+ sizeof(struct sof_ipc_stream_posn)))
+ vq_err(vq, "%s(): position update has wrong size %d!\n",
+ __func__, out);
+
+ if (!in) {
+ /* This queue should only contain "in" buffers */
+ vq_err(vq, "%s(): no input buffers!\n", __func__);
+ break;
+ }
+
+ spin_lock_irqsave(&dsp->posn_lock, flags);
+ list_add_tail(&buf->list, &dsp->posn_buf_list);
+ spin_unlock_irqrestore(&dsp->posn_lock, flags);
+
+ free = false;
+ break;
+ }
+
+ if (enable)
+ vhost_enable_notify(&dsp->dev, vq);
+
+ mutex_unlock(&vq->mutex);
+
+ if (free)
+ kfree(buf);
+ else
+ /* Try to send immediately if a position update is pending */
+ vhost_dsp_fill_posn_vqbuf(dsp);
+}
+
+static void vhost_dsp_posn_work(struct vhost_work *work)
+{
+ struct vhost_dsp *dsp = container_of(work, struct vhost_dsp, work);
+
+ /*
+ * If there is an available VQ buffer, notify immediately. This is the
+ * normal case, since the guest pre-queues position update VQ buffers.
+ */
+ vhost_dsp_fill_posn_vqbuf(dsp);
+}
+
+static int vhost_dsp_open(struct inode *inode, struct file *filp)
+{
+ struct miscdevice *misc = filp->private_data;
+ struct snd_sof_dev *sdev = dev_get_drvdata(misc->parent);
+ struct vhost_dsp *dsp = kvmalloc(sizeof(*dsp),
+ GFP_KERNEL | __GFP_RETRY_MAYFAIL);
+ unsigned int i;
+
+ if (!dsp)
+ return -ENOMEM;
+
+ dsp->snd = dsp_sof_client_add(sdev, dsp);
+ if (!dsp->snd) {
+ kvfree(dsp);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(dsp->vq_p); i++)
+ dsp->vq_p[i] = &dsp->vqs[i].vq;
+
+ dsp->vqs[SOF_VIRTIO_IPC_CMD_VQ].vq.handle_kick = handle_ipc_cmd_kick;
+ dsp->vqs[SOF_VIRTIO_POSN_VQ].vq.handle_kick = handle_posn_kick;
+ dsp->vqs[SOF_VIRTIO_DATA_VQ].vq.handle_kick = handle_data_kick;
+ /*
+ * TODO: do we ever want to support multiple guest machines per DSP, if
+ * not, we might as well perform all allocations when registering the
+ * misc device.
+ */
+ INIT_LIST_HEAD(&dsp->posn_list);
+ INIT_LIST_HEAD(&dsp->posn_buf_list);
+ spin_lock_init(&dsp->posn_lock);
+ dsp->active = false;
+ vhost_work_init(&dsp->work, vhost_dsp_posn_work);
+
+ vhost_dev_init(&dsp->dev, dsp->vq_p, SOF_VIRTIO_NUM_OF_VQS,
+ UIO_MAXIOV + VHOST_DSP_BATCH,
+ VHOST_DSP_PKT_WEIGHT, VHOST_DSP_WEIGHT);
+
+ /* Overwrite file private data */
+ filp->private_data = dsp;
+
+ return 0;
+}
+
+/*
+ * The device is closed by QEMU when the client driver is unloaded or the guest
+ * is shut down
+ */
+static int vhost_dsp_release(struct inode *inode, struct file *filp)
+{
+ struct vhost_dsp *dsp = filp->private_data;
+
+ vhost_work_flush(&dsp->dev, &dsp->work);
+ vhost_dev_cleanup(&dsp->dev);
+ vhost_poll_flush(&dsp->vqs[SOF_VIRTIO_POSN_VQ].vq.poll);
+ vhost_poll_flush(&dsp->vqs[SOF_VIRTIO_IPC_CMD_VQ].vq.poll);
+ vhost_poll_flush(&dsp->vqs[SOF_VIRTIO_DATA_VQ].vq.poll);
+
+ dsp_sof_client_release(dsp->snd);
+
+ kvfree(dsp);
+
+ return 0;
+}
+
+static const struct file_operations vhost_dsp_fops = {
+ .owner = THIS_MODULE,
+ .release = vhost_dsp_release,
+ .read_iter = vhost_dsp_chr_read_iter,
+ .write_iter = vhost_dsp_chr_write_iter,
+ .poll = vhost_dsp_chr_poll,
+ .unlocked_ioctl = vhost_dsp_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = vhost_dsp_compat_ioctl,
+#endif
+ .open = vhost_dsp_open,
+ .llseek = noop_llseek,
+};
+
+static struct miscdevice vhost_dsp_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "vhost-dsp",
+ .fops = &vhost_dsp_fops,
+};
+
+/* Always called from an interrupt thread context */
+static int dsp_sof_update_posn(struct vhost_dsp *dsp,
+ struct sof_ipc_stream_posn *posn)
+{
+ struct vhost_dsp_posn *entry;
+
+ if (!dsp->active)
+ return 0;
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ memcpy(&entry->posn, posn, sizeof(entry->posn));
+
+ /*
+ * Save the position update msg and send it when a vq buffer becomes
+ * available.
+ */
+ spin_lock_irq(&dsp->posn_lock);
+ list_add_tail(&entry->list, &dsp->posn_list);
+ spin_unlock_irq(&dsp->posn_lock);
+
+ /* posn update for guest */
+ vhost_work_queue(&dsp->dev, &dsp->work);
+
+ return 0;
+}
+
+static struct sof_vhost_ops vhost_dsp_ops = {
+ .update_posn = dsp_sof_update_posn,
+};
+
+static int __init dsp_sof_init(void)
+{
+ vhost_dsp_misc.parent = dsp_sof_dev_init(&vhost_dsp_ops);
+ if (!vhost_dsp_misc.parent)
+ return -ENODEV;
+
+ return misc_register(&vhost_dsp_misc);
+}
+
+static void __exit dsp_sof_exit(void)
+{
+ misc_deregister(&vhost_dsp_misc);
+}
+
+module_init(dsp_sof_init);
+module_exit(dsp_sof_exit);
+
+MODULE_VERSION("0.9");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Guennadi Liakhovetski");
+MODULE_DESCRIPTION("Host kernel accelerator for virtio sound");
--
1.9.3
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