--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtio vhost-user driver
+ *
+ * Copyright(c) 2019 Intel Corporation
+ *
+ * This module allows virtio devices to be used over a vhost-user socket.
+ *
+ * Guest devices can be instantiated by kernel module or command line
+ * parameters. One device will be created for each parameter. Syntax:
+ *
+ * [virtio_uml.]device=<socket>:<virtio_id>[:<platform_id>]
+ * where:
+ * <socket> := vhost-user socket path to connect
+ * <virtio_id> := virtio device id (as in virtio_ids.h)
+ * <platform_id> := (optional) platform device id
+ *
+ * example:
+ * virtio_uml.device=/var/uml.socket:1
+ *
+ * Based on Virtio MMIO driver by Pawel Moll, copyright 2011-2014, ARM Ltd.
+ */
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ring.h>
+#include <shared/as-layout.h>
+#include <irq_kern.h>
+#include <init.h>
+#include <os.h>
+#include "vhost_user.h"
+
+/* Workaround due to a conflict between irq_user.h and irqreturn.h */
+#ifdef IRQ_NONE
+#undef IRQ_NONE
+#endif
+
+#define MAX_SUPPORTED_QUEUE_SIZE 256
+
+#define to_virtio_uml_device(_vdev) \
+ container_of(_vdev, struct virtio_uml_device, vdev)
+
+struct virtio_uml_device {
+ struct virtio_device vdev;
+ struct platform_device *pdev;
+
+ int sock;
+ u64 features;
+ u64 protocol_features;
+ u8 status;
+};
+
+struct virtio_uml_vq_info {
+ int kick_fd, call_fd;
+ char name[32];
+};
+
+extern unsigned long long physmem_size, highmem;
+
+#define vu_err(vu_dev, ...) dev_err(&(vu_dev)->pdev->dev, __VA_ARGS__)
+
+/* Vhost-user protocol */
+
+static int full_sendmsg_fds(int fd, const void *buf, unsigned int len,
+ const int *fds, unsigned int fds_num)
+{
+ int rc;
+
+ do {
+ rc = os_sendmsg_fds(fd, buf, len, fds, fds_num);
+ if (rc > 0) {
+ buf += rc;
+ len -= rc;
+ fds = NULL;
+ fds_num = 0;
+ }
+ } while (len && (rc >= 0 || rc == -EINTR));
+
+ if (rc < 0)
+ return rc;
+ return 0;
+}
+
+static int full_read(int fd, void *buf, int len)
+{
+ int rc;
+
+ do {
+ rc = os_read_file(fd, buf, len);
+ if (rc > 0) {
+ buf += rc;
+ len -= rc;
+ }
+ } while (len && (rc > 0 || rc == -EINTR));
+
+ if (rc < 0)
+ return rc;
+ if (rc == 0)
+ return -ECONNRESET;
+ return 0;
+}
+
+static int vhost_user_recv_header(struct virtio_uml_device *vu_dev,
+ struct vhost_user_msg *msg)
+{
+ size_t size = sizeof(msg->header);
+ int rc;
+
+ rc = full_read(vu_dev->sock, (void *) msg, size);
+ if (rc)
+ return rc;
+ if (msg->header.flags != (VHOST_USER_FLAG_REPLY | VHOST_USER_VERSION))
+ return -EPROTO;
+ return 0;
+}
+
+static int vhost_user_recv(struct virtio_uml_device *vu_dev,
+ struct vhost_user_msg *msg,
+ size_t max_payload_size)
+{
+ size_t size;
+ int rc = vhost_user_recv_header(vu_dev, msg);
+
+ if (rc)
+ return rc;
+ size = msg->header.size;
+ if (size > max_payload_size)
+ return -EPROTO;
+ return full_read(vu_dev->sock, (void *) &msg->payload, size);
+}
+
+static int vhost_user_recv_u64(struct virtio_uml_device *vu_dev,
+ u64 *value)
+{
+ struct vhost_user_msg msg;
+ int rc = vhost_user_recv(vu_dev, &msg, sizeof(msg.payload.integer));
+
+ if (rc)
+ return rc;
+ if (msg.header.size != sizeof(msg.payload.integer))
+ return -EPROTO;
+ *value = msg.payload.integer;
+ return 0;
+}
+
+static int vhost_user_send(struct virtio_uml_device *vu_dev,
+ struct vhost_user_msg *msg,
+ int *fds, size_t num_fds)
+{
+ size_t size = sizeof(msg->header) + msg->header.size;
+
+ msg->header.flags |= VHOST_USER_VERSION;
+ return full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds);
+}
+
+static int vhost_user_send_no_payload(struct virtio_uml_device *vu_dev,
+ u32 request)
+{
+ struct vhost_user_msg msg = {
+ .header.request = request,
+ };
+
+ return vhost_user_send(vu_dev, &msg, NULL, 0);
+}
+
+static int vhost_user_send_u64(struct virtio_uml_device *vu_dev,
+ u32 request, u64 value)
+{
+ struct vhost_user_msg msg = {
+ .header.request = request,
+ .header.size = sizeof(msg.payload.integer),
+ .payload.integer = value,
+ };
+
+ return vhost_user_send(vu_dev, &msg, NULL, 0);
+}
+
+static int vhost_user_set_owner(struct virtio_uml_device *vu_dev)
+{
+ return vhost_user_send_no_payload(vu_dev, VHOST_USER_SET_OWNER);
+}
+
+static int vhost_user_get_features(struct virtio_uml_device *vu_dev,
+ u64 *features)
+{
+ int rc = vhost_user_send_no_payload(vu_dev, VHOST_USER_GET_FEATURES);
+
+ if (rc)
+ return rc;
+ return vhost_user_recv_u64(vu_dev, features);
+}
+
+static int vhost_user_set_features(struct virtio_uml_device *vu_dev,
+ u64 features)
+{
+ return vhost_user_send_u64(vu_dev, VHOST_USER_SET_FEATURES, features);
+}
+
+static int vhost_user_get_protocol_features(struct virtio_uml_device *vu_dev,
+ u64 *protocol_features)
+{
+ int rc = vhost_user_send_no_payload(vu_dev,
+ VHOST_USER_GET_PROTOCOL_FEATURES);
+
+ if (rc)
+ return rc;
+ return vhost_user_recv_u64(vu_dev, protocol_features);
+}
+
+static int vhost_user_set_protocol_features(struct virtio_uml_device *vu_dev,
+ u64 protocol_features)
+{
+ return vhost_user_send_u64(vu_dev, VHOST_USER_SET_PROTOCOL_FEATURES,
+ protocol_features);
+}
+
+static int vhost_user_init(struct virtio_uml_device *vu_dev)
+{
+ int rc = vhost_user_set_owner(vu_dev);
+
+ if (rc)
+ return rc;
+ rc = vhost_user_get_features(vu_dev, &vu_dev->features);
+ if (rc)
+ return rc;
+
+ if (vu_dev->features & BIT_ULL(VHOST_USER_F_PROTOCOL_FEATURES)) {
+ rc = vhost_user_get_protocol_features(vu_dev,
+ &vu_dev->protocol_features);
+ if (rc)
+ return rc;
+ vu_dev->protocol_features &= VHOST_USER_SUPPORTED_PROTOCOL_F;
+ rc = vhost_user_set_protocol_features(vu_dev,
+ vu_dev->protocol_features);
+ }
+ return rc;
+}
+
+static void vhost_user_get_config(struct virtio_uml_device *vu_dev,
+ u32 offset, void *buf, u32 len)
+{
+ u32 cfg_size = offset + len;
+ struct vhost_user_msg *msg;
+ size_t payload_size = sizeof(msg->payload.config) + cfg_size;
+ size_t msg_size = sizeof(msg->header) + payload_size;
+ int rc;
+
+ if (!(vu_dev->protocol_features &
+ BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG)))
+ return;
+
+ msg = kzalloc(msg_size, GFP_KERNEL);
+ if (!msg)
+ return;
+ msg->header.request = VHOST_USER_GET_CONFIG;
+ msg->header.size = payload_size;
+ msg->payload.config.offset = 0;
+ msg->payload.config.size = cfg_size;
+
+ rc = vhost_user_send(vu_dev, msg, NULL, 0);
+ if (rc) {
+ vu_err(vu_dev, "sending VHOST_USER_GET_CONFIG failed: %d\n",
+ rc);
+ goto free;
+ }
+
+ rc = vhost_user_recv(vu_dev, msg, msg_size);
+ if (rc) {
+ vu_err(vu_dev,
+ "receiving VHOST_USER_GET_CONFIG response failed: %d\n",
+ rc);
+ goto free;
+ }
+
+ if (msg->header.size != payload_size ||
+ msg->payload.config.size != cfg_size) {
+ rc = -EPROTO;
+ vu_err(vu_dev,
+ "Invalid VHOST_USER_GET_CONFIG sizes (payload %d expected %zu, config %u expected %u)\n",
+ msg->header.size, payload_size,
+ msg->payload.config.size, cfg_size);
+ goto free;
+ }
+ memcpy(buf, msg->payload.config.payload + offset, len);
+
+free:
+ kfree(msg);
+}
+
+static void vhost_user_set_config(struct virtio_uml_device *vu_dev,
+ u32 offset, const void *buf, u32 len)
+{
+ struct vhost_user_msg *msg;
+ size_t payload_size = sizeof(msg->payload.config) + len;
+ size_t msg_size = sizeof(msg->header) + payload_size;
+ int rc;
+
+ if (!(vu_dev->protocol_features &
+ BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG)))
+ return;
+
+ msg = kzalloc(msg_size, GFP_KERNEL);
+ if (!msg)
+ return;
+ msg->header.request = VHOST_USER_SET_CONFIG;
+ msg->header.size = payload_size;
+ msg->payload.config.offset = offset;
+ msg->payload.config.size = len;
+ memcpy(msg->payload.config.payload, buf, len);
+
+ rc = vhost_user_send(vu_dev, msg, NULL, 0);
+ if (rc)
+ vu_err(vu_dev, "sending VHOST_USER_SET_CONFIG failed: %d\n",
+ rc);
+
+ kfree(msg);
+}
+
+static int vhost_user_init_mem_region(u64 addr, u64 size, int *fd_out,
+ struct vhost_user_mem_region *region_out)
+{
+ unsigned long long mem_offset;
+ int rc = phys_mapping(addr, &mem_offset);
+
+ if (WARN(rc < 0, "phys_mapping of 0x%llx returned %d\n", addr, rc))
+ return -EFAULT;
+ *fd_out = rc;
+ region_out->guest_addr = addr;
+ region_out->user_addr = addr;
+ region_out->size = size;
+ region_out->mmap_offset = mem_offset;
+
+ /* Ensure mapping is valid for the entire region */
+ rc = phys_mapping(addr + size - 1, &mem_offset);
+ if (WARN(rc != *fd_out, "phys_mapping of 0x%llx failed: %d != %d\n",
+ addr + size - 1, rc, *fd_out))
+ return -EFAULT;
+ return 0;
+}
+
+static int vhost_user_set_mem_table(struct virtio_uml_device *vu_dev)
+{
+ struct vhost_user_msg msg = {
+ .header.request = VHOST_USER_SET_MEM_TABLE,
+ .header.size = sizeof(msg.payload.mem_regions),
+ .payload.mem_regions.num = 1,
+ };
+ unsigned long reserved = uml_reserved - uml_physmem;
+ int fds[2];
+ int rc;
+
+ /*
+ * This is a bit tricky, see also the comment with setup_physmem().
+ *
+ * Essentially, setup_physmem() uses a file to mmap() our physmem,
+ * but the code and data we *already* have is omitted. To us, this
+ * is no difference, since they both become part of our address
+ * space and memory consumption. To somebody looking in from the
+ * outside, however, it is different because the part of our memory
+ * consumption that's already part of the binary (code/data) is not
+ * mapped from the file, so it's not visible to another mmap from
+ * the file descriptor.
+ *
+ * Thus, don't advertise this space to the vhost-user slave. This
+ * means that the slave will likely abort or similar when we give
+ * it an address from the hidden range, since it's not marked as
+ * a valid address, but at least that way we detect the issue and
+ * don't just have the slave read an all-zeroes buffer from the
+ * shared memory file, or write something there that we can never
+ * see (depending on the direction of the virtqueue traffic.)
+ *
+ * Since we usually don't want to use .text for virtio buffers,
+ * this effectively means that you cannot use
+ * 1) global variables, which are in the .bss and not in the shm
+ * file-backed memory
+ * 2) the stack in some processes, depending on where they have
+ * their stack (or maybe only no interrupt stack?)
+ *
+ * The stack is already not typically valid for DMA, so this isn't
+ * much of a restriction, but global variables might be encountered.
+ *
+ * It might be possible to fix it by copying around the data that's
+ * between bss_start and where we map the file now, but it's not
+ * something that you typically encounter with virtio drivers, so
+ * it didn't seem worthwhile.
+ */
+ rc = vhost_user_init_mem_region(reserved, physmem_size - reserved,
+ &fds[0],
+ &msg.payload.mem_regions.regions[0]);
+
+ if (rc < 0)
+ return rc;
+ if (highmem) {
+ msg.payload.mem_regions.num++;
+ rc = vhost_user_init_mem_region(__pa(end_iomem), highmem,
+ &fds[1], &msg.payload.mem_regions.regions[1]);
+ if (rc < 0)
+ return rc;
+ }
+
+ return vhost_user_send(vu_dev, &msg, fds, msg.payload.mem_regions.num);
+}
+
+static int vhost_user_set_vring_state(struct virtio_uml_device *vu_dev,
+ u32 request, u32 index, u32 num)
+{
+ struct vhost_user_msg msg = {
+ .header.request = request,
+ .header.size = sizeof(msg.payload.vring_state),
+ .payload.vring_state.index = index,
+ .payload.vring_state.num = num,
+ };
+
+ return vhost_user_send(vu_dev, &msg, NULL, 0);
+}
+
+static int vhost_user_set_vring_num(struct virtio_uml_device *vu_dev,
+ u32 index, u32 num)
+{
+ return vhost_user_set_vring_state(vu_dev, VHOST_USER_SET_VRING_NUM,
+ index, num);
+}
+
+static int vhost_user_set_vring_base(struct virtio_uml_device *vu_dev,
+ u32 index, u32 offset)
+{
+ return vhost_user_set_vring_state(vu_dev, VHOST_USER_SET_VRING_BASE,
+ index, offset);
+}
+
+static int vhost_user_set_vring_addr(struct virtio_uml_device *vu_dev,
+ u32 index, u64 desc, u64 used, u64 avail,
+ u64 log)
+{
+ struct vhost_user_msg msg = {
+ .header.request = VHOST_USER_SET_VRING_ADDR,
+ .header.size = sizeof(msg.payload.vring_addr),
+ .payload.vring_addr.index = index,
+ .payload.vring_addr.desc = desc,
+ .payload.vring_addr.used = used,
+ .payload.vring_addr.avail = avail,
+ .payload.vring_addr.log = log,
+ };
+
+ return vhost_user_send(vu_dev, &msg, NULL, 0);
+}
+
+static int vhost_user_set_vring_fd(struct virtio_uml_device *vu_dev,
+ u32 request, int index, int fd)
+{
+ struct vhost_user_msg msg = {
+ .header.request = request,
+ .header.size = sizeof(msg.payload.integer),
+ .payload.integer = index,
+ };
+
+ if (index & ~VHOST_USER_VRING_INDEX_MASK)
+ return -EINVAL;
+ if (fd < 0) {
+ msg.payload.integer |= VHOST_USER_VRING_POLL_MASK;
+ return vhost_user_send(vu_dev, &msg, NULL, 0);
+ }
+ return vhost_user_send(vu_dev, &msg, &fd, 1);
+}
+
+static int vhost_user_set_vring_call(struct virtio_uml_device *vu_dev,
+ int index, int fd)
+{
+ return vhost_user_set_vring_fd(vu_dev, VHOST_USER_SET_VRING_CALL,
+ index, fd);
+}
+
+static int vhost_user_set_vring_kick(struct virtio_uml_device *vu_dev,
+ int index, int fd)
+{
+ return vhost_user_set_vring_fd(vu_dev, VHOST_USER_SET_VRING_KICK,
+ index, fd);
+}
+
+static int vhost_user_set_vring_enable(struct virtio_uml_device *vu_dev,
+ u32 index, bool enable)
+{
+ if (!(vu_dev->features & BIT_ULL(VHOST_USER_F_PROTOCOL_FEATURES)))
+ return 0;
+
+ return vhost_user_set_vring_state(vu_dev, VHOST_USER_SET_VRING_ENABLE,
+ index, enable);
+}
+
+
+/* Virtio interface */
+
+static bool vu_notify(struct virtqueue *vq)
+{
+ struct virtio_uml_vq_info *info = vq->priv;
+ const uint64_t n = 1;
+ int rc;
+
+ do {
+ rc = os_write_file(info->kick_fd, &n, sizeof(n));
+ } while (rc == -EINTR);
+ return !WARN(rc != sizeof(n), "write returned %d\n", rc);
+}
+
+static irqreturn_t vu_interrupt(int irq, void *opaque)
+{
+ struct virtqueue *vq = opaque;
+ struct virtio_uml_vq_info *info = vq->priv;
+ uint64_t n;
+ int rc;
+ irqreturn_t ret = IRQ_NONE;
+
+ do {
+ rc = os_read_file(info->call_fd, &n, sizeof(n));
+ if (rc == sizeof(n))
+ ret |= vring_interrupt(irq, vq);
+ } while (rc == sizeof(n) || rc == -EINTR);
+ WARN(rc != -EAGAIN, "read returned %d\n", rc);
+ return ret;
+}
+
+
+static void vu_get(struct virtio_device *vdev, unsigned offset,
+ void *buf, unsigned len)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ vhost_user_get_config(vu_dev, offset, buf, len);
+}
+
+static void vu_set(struct virtio_device *vdev, unsigned offset,
+ const void *buf, unsigned len)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ vhost_user_set_config(vu_dev, offset, buf, len);
+}
+
+static u8 vu_get_status(struct virtio_device *vdev)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ return vu_dev->status;
+}
+
+static void vu_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ vu_dev->status = status;
+}
+
+static void vu_reset(struct virtio_device *vdev)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ vu_dev->status = 0;
+}
+
+static void vu_del_vq(struct virtqueue *vq)
+{
+ struct virtio_uml_vq_info *info = vq->priv;
+
+ um_free_irq(VIRTIO_IRQ, vq);
+
+ os_close_file(info->call_fd);
+ os_close_file(info->kick_fd);
+
+ vring_del_virtqueue(vq);
+ kfree(info);
+}
+
+static void vu_del_vqs(struct virtio_device *vdev)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+ struct virtqueue *vq, *n;
+ u64 features;
+
+ /* Note: reverse order as a workaround to a decoding bug in snabb */
+ list_for_each_entry_reverse(vq, &vdev->vqs, list)
+ WARN_ON(vhost_user_set_vring_enable(vu_dev, vq->index, false));
+
+ /* Ensure previous messages have been processed */
+ WARN_ON(vhost_user_get_features(vu_dev, &features));
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+ vu_del_vq(vq);
+}
+
+static int vu_setup_vq_call_fd(struct virtio_uml_device *vu_dev,
+ struct virtqueue *vq)
+{
+ struct virtio_uml_vq_info *info = vq->priv;
+ int call_fds[2];
+ int rc;
+
+ /* Use a pipe for call fd, since SIGIO is not supported for eventfd */
+ rc = os_pipe(call_fds, true, true);
+ if (rc < 0)
+ return rc;
+
+ info->call_fd = call_fds[0];
+ rc = um_request_irq(VIRTIO_IRQ, info->call_fd, IRQ_READ,
+ vu_interrupt, IRQF_SHARED, info->name, vq);
+ if (rc)
+ goto close_both;
+
+ rc = vhost_user_set_vring_call(vu_dev, vq->index, call_fds[1]);
+ if (rc)
+ goto release_irq;
+
+ goto out;
+
+release_irq:
+ um_free_irq(VIRTIO_IRQ, vq);
+close_both:
+ os_close_file(call_fds[0]);
+out:
+ /* Close (unused) write end of call fds */
+ os_close_file(call_fds[1]);
+
+ return rc;
+}
+
+static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
+ unsigned index, vq_callback_t *callback,
+ const char *name, bool ctx)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+ struct platform_device *pdev = vu_dev->pdev;
+ struct virtio_uml_vq_info *info;
+ struct virtqueue *vq;
+ int num = MAX_SUPPORTED_QUEUE_SIZE;
+ int rc;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ rc = -ENOMEM;
+ goto error_kzalloc;
+ }
+ snprintf(info->name, sizeof(info->name), "%s.%d-%s", pdev->name,
+ pdev->id, name);
+
+ vq = vring_create_virtqueue(index, num, PAGE_SIZE, vdev, true, true,
+ ctx, vu_notify, callback, info->name);
+ if (!vq) {
+ rc = -ENOMEM;
+ goto error_create;
+ }
+ vq->priv = info;
+ num = virtqueue_get_vring_size(vq);
+
+ rc = os_eventfd(0, 0);
+ if (rc < 0)
+ goto error_kick;
+ info->kick_fd = rc;
+
+ rc = vu_setup_vq_call_fd(vu_dev, vq);
+ if (rc)
+ goto error_call;
+
+ rc = vhost_user_set_vring_num(vu_dev, index, num);
+ if (rc)
+ goto error_setup;
+
+ rc = vhost_user_set_vring_base(vu_dev, index, 0);
+ if (rc)
+ goto error_setup;
+
+ rc = vhost_user_set_vring_addr(vu_dev, index,
+ virtqueue_get_desc_addr(vq),
+ virtqueue_get_used_addr(vq),
+ virtqueue_get_avail_addr(vq),
+ (u64) -1);
+ if (rc)
+ goto error_setup;
+
+ return vq;
+
+error_setup:
+ um_free_irq(VIRTIO_IRQ, vq);
+ os_close_file(info->call_fd);
+error_call:
+ os_close_file(info->kick_fd);
+error_kick:
+ vring_del_virtqueue(vq);
+error_create:
+ kfree(info);
+error_kzalloc:
+ return ERR_PTR(rc);
+}
+
+static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[], vq_callback_t *callbacks[],
+ const char * const names[], const bool *ctx,
+ struct irq_affinity *desc)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+ int i, queue_idx = 0, rc;
+ struct virtqueue *vq;
+
+ rc = vhost_user_set_mem_table(vu_dev);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < nvqs; ++i) {
+ if (!names[i]) {
+ vqs[i] = NULL;
+ continue;
+ }
+
+ vqs[i] = vu_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
+ ctx ? ctx[i] : false);
+ if (IS_ERR(vqs[i])) {
+ rc = PTR_ERR(vqs[i]);
+ goto error_setup;
+ }
+ }
+
+ list_for_each_entry(vq, &vdev->vqs, list) {
+ struct virtio_uml_vq_info *info = vq->priv;
+
+ rc = vhost_user_set_vring_kick(vu_dev, vq->index,
+ info->kick_fd);
+ if (rc)
+ goto error_setup;
+
+ rc = vhost_user_set_vring_enable(vu_dev, vq->index, true);
+ if (rc)
+ goto error_setup;
+ }
+
+ return 0;
+
+error_setup:
+ vu_del_vqs(vdev);
+ return rc;
+}
+
+static u64 vu_get_features(struct virtio_device *vdev)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ return vu_dev->features;
+}
+
+static int vu_finalize_features(struct virtio_device *vdev)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+ u64 supported = vdev->features & VHOST_USER_SUPPORTED_F;
+
+ vring_transport_features(vdev);
+ vu_dev->features = vdev->features | supported;
+
+ return vhost_user_set_features(vu_dev, vu_dev->features);
+}
+
+static const char *vu_bus_name(struct virtio_device *vdev)
+{
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ return vu_dev->pdev->name;
+}
+
+static const struct virtio_config_ops virtio_uml_config_ops = {
+ .get = vu_get,
+ .set = vu_set,
+ .get_status = vu_get_status,
+ .set_status = vu_set_status,
+ .reset = vu_reset,
+ .find_vqs = vu_find_vqs,
+ .del_vqs = vu_del_vqs,
+ .get_features = vu_get_features,
+ .finalize_features = vu_finalize_features,
+ .bus_name = vu_bus_name,
+};
+
+
+static void virtio_uml_release_dev(struct device *d)
+{
+ struct virtio_device *vdev =
+ container_of(d, struct virtio_device, dev);
+ struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
+
+ os_close_file(vu_dev->sock);
+}
+
+/* Platform device */
+
+struct virtio_uml_platform_data {
+ u32 virtio_device_id;
+ const char *socket_path;
+};
+
+static int virtio_uml_probe(struct platform_device *pdev)
+{
+ struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
+ struct virtio_uml_device *vu_dev;
+ int rc;
+
+ if (!pdata)
+ return -EINVAL;
+
+ vu_dev = devm_kzalloc(&pdev->dev, sizeof(*vu_dev), GFP_KERNEL);
+ if (!vu_dev)
+ return -ENOMEM;
+
+ vu_dev->vdev.dev.parent = &pdev->dev;
+ vu_dev->vdev.dev.release = virtio_uml_release_dev;
+ vu_dev->vdev.config = &virtio_uml_config_ops;
+ vu_dev->vdev.id.device = pdata->virtio_device_id;
+ vu_dev->vdev.id.vendor = VIRTIO_DEV_ANY_ID;
+ vu_dev->pdev = pdev;
+
+ do {
+ rc = os_connect_socket(pdata->socket_path);
+ } while (rc == -EINTR);
+ if (rc < 0)
+ return rc;
+ vu_dev->sock = rc;
+
+ rc = vhost_user_init(vu_dev);
+ if (rc)
+ goto error_init;
+
+ platform_set_drvdata(pdev, vu_dev);
+
+ rc = register_virtio_device(&vu_dev->vdev);
+ if (rc)
+ put_device(&vu_dev->vdev.dev);
+ return rc;
+
+error_init:
+ os_close_file(vu_dev->sock);
+ return rc;
+}
+
+static int virtio_uml_remove(struct platform_device *pdev)
+{
+ struct virtio_uml_device *vu_dev = platform_get_drvdata(pdev);
+
+ unregister_virtio_device(&vu_dev->vdev);
+ return 0;
+}
+
+/* Command line device list */
+
+static void vu_cmdline_release_dev(struct device *d)
+{
+}
+
+static struct device vu_cmdline_parent = {
+ .init_name = "virtio-uml-cmdline",
+ .release = vu_cmdline_release_dev,
+};
+
+static bool vu_cmdline_parent_registered;
+static int vu_cmdline_id;
+
+static int vu_cmdline_set(const char *device, const struct kernel_param *kp)
+{
+ const char *ids = strchr(device, ':');
+ unsigned int virtio_device_id;
+ int processed, consumed, err;
+ char *socket_path;
+ struct virtio_uml_platform_data pdata;
+ struct platform_device *pdev;
+
+ if (!ids || ids == device)
+ return -EINVAL;
+
+ processed = sscanf(ids, ":%u%n:%d%n",
+ &virtio_device_id, &consumed,
+ &vu_cmdline_id, &consumed);
+
+ if (processed < 1 || ids[consumed])
+ return -EINVAL;
+
+ if (!vu_cmdline_parent_registered) {
+ err = device_register(&vu_cmdline_parent);
+ if (err) {
+ pr_err("Failed to register parent device!\n");
+ put_device(&vu_cmdline_parent);
+ return err;
+ }
+ vu_cmdline_parent_registered = true;
+ }
+
+ socket_path = kmemdup_nul(device, ids - device, GFP_KERNEL);
+ if (!socket_path)
+ return -ENOMEM;
+
+ pdata.virtio_device_id = (u32) virtio_device_id;
+ pdata.socket_path = socket_path;
+
+ pr_info("Registering device virtio-uml.%d id=%d at %s\n",
+ vu_cmdline_id, virtio_device_id, socket_path);
+
+ pdev = platform_device_register_data(&vu_cmdline_parent, "virtio-uml",
+ vu_cmdline_id++, &pdata,
+ sizeof(pdata));
+ err = PTR_ERR_OR_ZERO(pdev);
+ if (err)
+ goto free;
+ return 0;
+
+free:
+ kfree(socket_path);
+ return err;
+}
+
+static int vu_cmdline_get_device(struct device *dev, void *data)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
+ char *buffer = data;
+ unsigned int len = strlen(buffer);
+
+ snprintf(buffer + len, PAGE_SIZE - len, "%s:%d:%d\n",
+ pdata->socket_path, pdata->virtio_device_id, pdev->id);
+ return 0;
+}
+
+static int vu_cmdline_get(char *buffer, const struct kernel_param *kp)
+{
+ buffer[0] = '\0';
+ if (vu_cmdline_parent_registered)
+ device_for_each_child(&vu_cmdline_parent, buffer,
+ vu_cmdline_get_device);
+ return strlen(buffer) + 1;
+}
+
+static const struct kernel_param_ops vu_cmdline_param_ops = {
+ .set = vu_cmdline_set,
+ .get = vu_cmdline_get,
+};
+
+device_param_cb(device, &vu_cmdline_param_ops, NULL, S_IRUSR);
+__uml_help(vu_cmdline_param_ops,
+"virtio_uml.device=<socket>:<virtio_id>[:<platform_id>]\n"
+" Configure a virtio device over a vhost-user socket.\n"
+" See virtio_ids.h for a list of possible virtio device id values.\n"
+" Optionally use a specific platform_device id.\n\n"
+);
+
+
+static int vu_unregister_cmdline_device(struct device *dev, void *data)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
+
+ kfree(pdata->socket_path);
+ platform_device_unregister(pdev);
+ return 0;
+}
+
+static void vu_unregister_cmdline_devices(void)
+{
+ if (vu_cmdline_parent_registered) {
+ device_for_each_child(&vu_cmdline_parent, NULL,
+ vu_unregister_cmdline_device);
+ device_unregister(&vu_cmdline_parent);
+ vu_cmdline_parent_registered = false;
+ }
+}
+
+/* Platform driver */
+
+static const struct of_device_id virtio_uml_match[] = {
+ { .compatible = "virtio,uml", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, virtio_uml_match);
+
+static struct platform_driver virtio_uml_driver = {
+ .probe = virtio_uml_probe,
+ .remove = virtio_uml_remove,
+ .driver = {
+ .name = "virtio-uml",
+ .of_match_table = virtio_uml_match,
+ },
+};
+
+static int __init virtio_uml_init(void)
+{
+ return platform_driver_register(&virtio_uml_driver);
+}
+
+static void __exit virtio_uml_exit(void)
+{
+ platform_driver_unregister(&virtio_uml_driver);
+ vu_unregister_cmdline_devices();
+}
+
+module_init(virtio_uml_init);
+module_exit(virtio_uml_exit);
+__uml_exitcall(virtio_uml_exit);
+
+MODULE_DESCRIPTION("UML driver for vhost-user virtio devices");
+MODULE_LICENSE("GPL");
projects / linux.git / commitdiff