1 files changed, 279 insertions, 0 deletions
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
new file mode 100644
index 000000000..54ee93b71
--- /dev/null
+++ b/hw/9pfs/virtio-9p-device.c
@@ -0,0 +1,279 @@
+/*
+ * Virtio 9p backend
+ *
+ * Copyright IBM, Corp. 2010
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+/*
+ * Not so fast! You might want to read the 9p developer docs first:
+ * https://wiki.qemu.org/Documentation/9p
+ */
+
+#include "qemu/osdep.h"
+#include "hw/virtio/virtio.h"
+#include "qemu/sockets.h"
+#include "virtio-9p.h"
+#include "fsdev/qemu-fsdev.h"
+#include "coth.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/virtio-access.h"
+#include "qemu/iov.h"
+#include "qemu/module.h"
+#include "sysemu/qtest.h"
+
+static void virtio_9p_push_and_notify(V9fsPDU *pdu)
+{
+    V9fsState *s = pdu->s;
+    V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
+    VirtQueueElement *elem = v->elems[pdu->idx];
+
+    /* push onto queue and notify */
+    virtqueue_push(v->vq, elem, pdu->size);
+    g_free(elem);
+    v->elems[pdu->idx] = NULL;
+
+    /* FIXME: we should batch these completions */
+    virtio_notify(VIRTIO_DEVICE(v), v->vq);
+}
+
+static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+    V9fsVirtioState *v = (V9fsVirtioState *)vdev;
+    V9fsState *s = &v->state;
+    V9fsPDU *pdu;
+    ssize_t len;
+    VirtQueueElement *elem;
+
+    while ((pdu = pdu_alloc(s))) {
+        P9MsgHeader out;
+
+        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+        if (!elem) {
+            goto out_free_pdu;
+        }
+
+        if (iov_size(elem->in_sg, elem->in_num) < 7) {
+            virtio_error(vdev,
+                         "The guest sent a VirtFS request without space for "
+                         "the reply");
+            goto out_free_req;
+        }
+
+        len = iov_to_buf(elem->out_sg, elem->out_num, 0, &out, 7);
+        if (len != 7) {
+            virtio_error(vdev, "The guest sent a malformed VirtFS request: "
+                         "header size is %zd, should be 7", len);
+            goto out_free_req;
+        }
+
+        v->elems[pdu->idx] = elem;
+
+        pdu_submit(pdu, &out);
+    }
+
+    return;
+
+out_free_req:
+    virtqueue_detach_element(vq, elem, 0);
+    g_free(elem);
+out_free_pdu:
+    pdu_free(pdu);
+}
+
+static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
+                                       Error **errp)
+{
+    virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
+    return features;
+}
+
+static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
+{
+    int len;
+    struct virtio_9p_config *cfg;
+    V9fsVirtioState *v = VIRTIO_9P(vdev);
+    V9fsState *s = &v->state;
+
+    len = strlen(s->tag);
+    cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
+    virtio_stw_p(vdev, &cfg->tag_len, len);
+    /* We don't copy the terminating null to config space */
+    memcpy(cfg->tag, s->tag, len);
+    memcpy(config, cfg, v->config_size);
+    g_free(cfg);
+}
+
+static void virtio_9p_reset(VirtIODevice *vdev)
+{
+    V9fsVirtioState *v = (V9fsVirtioState *)vdev;
+
+    v9fs_reset(&v->state);
+}
+
+static ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
+                                   const char *fmt, va_list ap)
+{
+    V9fsState *s = pdu->s;
+    V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
+    VirtQueueElement *elem = v->elems[pdu->idx];
+    ssize_t ret;
+
+    ret = v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
+    if (ret < 0) {
+        VirtIODevice *vdev = VIRTIO_DEVICE(v);
+
+        virtio_error(vdev, "Failed to encode VirtFS reply type %d",
+                     pdu->id + 1);
+    }
+    return ret;
+}
+
+static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
+                                     const char *fmt, va_list ap)
+{
+    V9fsState *s = pdu->s;
+    V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
+    VirtQueueElement *elem = v->elems[pdu->idx];
+    ssize_t ret;
+
+    ret = v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
+    if (ret < 0) {
+        VirtIODevice *vdev = VIRTIO_DEVICE(v);
+
+        virtio_error(vdev, "Failed to decode VirtFS request type %d", pdu->id);
+    }
+    return ret;
+}
+
+static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
+                                        unsigned int *pniov, size_t size)
+{
+    V9fsState *s = pdu->s;
+    V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
+    VirtQueueElement *elem = v->elems[pdu->idx];
+    size_t buf_size = iov_size(elem->in_sg, elem->in_num);
+
+    if (buf_size < size) {
+        VirtIODevice *vdev = VIRTIO_DEVICE(v);
+
+        virtio_error(vdev,
+                     "VirtFS reply type %d needs %zu bytes, buffer has %zu",
+                     pdu->id + 1, size, buf_size);
+    }
+
+    *piov = elem->in_sg;
+    *pniov = elem->in_num;
+}
+
+static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
+                                         unsigned int *pniov, size_t size)
+{
+    V9fsState *s = pdu->s;
+    V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
+    VirtQueueElement *elem = v->elems[pdu->idx];
+    size_t buf_size = iov_size(elem->out_sg, elem->out_num);
+
+    if (buf_size < size) {
+        VirtIODevice *vdev = VIRTIO_DEVICE(v);
+
+        virtio_error(vdev,
+                     "VirtFS request type %d needs %zu bytes, buffer has %zu",
+                     pdu->id, size, buf_size);
+    }
+
+    *piov = elem->out_sg;
+    *pniov = elem->out_num;
+}
+
+static const V9fsTransport virtio_9p_transport = {
+    .pdu_vmarshal = virtio_pdu_vmarshal,
+    .pdu_vunmarshal = virtio_pdu_vunmarshal,
+    .init_in_iov_from_pdu = virtio_init_in_iov_from_pdu,
+    .init_out_iov_from_pdu = virtio_init_out_iov_from_pdu,
+    .push_and_notify = virtio_9p_push_and_notify,
+};
+
+static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    V9fsVirtioState *v = VIRTIO_9P(dev);
+    V9fsState *s = &v->state;
+    FsDriverEntry *fse = get_fsdev_fsentry(s->fsconf.fsdev_id);
+
+    if (qtest_enabled() && fse) {
+        fse->export_flags |= V9FS_NO_PERF_WARN;
+    }
+
+    if (v9fs_device_realize_common(s, &virtio_9p_transport, errp)) {
+        return;
+    }
+
+    v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
+    virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
+    v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
+}
+
+static void virtio_9p_device_unrealize(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    V9fsVirtioState *v = VIRTIO_9P(dev);
+    V9fsState *s = &v->state;
+
+    virtio_delete_queue(v->vq);
+    virtio_cleanup(vdev);
+    v9fs_device_unrealize_common(s);
+}
+
+/* virtio-9p device */
+
+static const VMStateDescription vmstate_virtio_9p = {
+    .name = "virtio-9p",
+    .minimum_version_id = 1,
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_VIRTIO_DEVICE,
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static Property virtio_9p_properties[] = {
+    DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
+    DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_9p_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+    device_class_set_props(dc, virtio_9p_properties);
+    dc->vmsd = &vmstate_virtio_9p;
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    vdc->realize = virtio_9p_device_realize;
+    vdc->unrealize = virtio_9p_device_unrealize;
+    vdc->get_features = virtio_9p_get_features;
+    vdc->get_config = virtio_9p_get_config;
+    vdc->reset = virtio_9p_reset;
+}
+
+static const TypeInfo virtio_device_info = {
+    .name = TYPE_VIRTIO_9P,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(V9fsVirtioState),
+    .class_init = virtio_9p_class_init,
+};
+
+static void virtio_9p_register_types(void)
+{
+    type_register_static(&virtio_device_info);
+}
+
+type_init(virtio_9p_register_types)