vhost: Allow device specific fields per vq

This is useful for any device who wants device specific fields per vq.
For example, tcm_vhost wants a per vq field to track requests which are
in flight on the vq. Also, on top of this we can add patches to move
things like ubufs from vhost.h out to net.c.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 37 insertions, 18 deletions

diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
index 1677238d281f..99d3480450e7 100644
--- a/drivers/vhost/tcm_vhost.c
+++ b/drivers/vhost/tcm_vhost.c
@@ -74,13 +74,17 @@ enum {
 #define VHOST_SCSI_MAX_VQ       128
 #define VHOST_SCSI_MAX_EVENT    128
 
+struct vhost_scsi_virtqueue {
+        struct vhost_virtqueue vq;
+};
+
 struct vhost_scsi {
         /* Protected by vhost_scsi->dev.mutex */
         struct tcm_vhost_tpg **vs_tpg;
         char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
 
         struct vhost_dev dev;
-        struct vhost_virtqueue vqs[VHOST_SCSI_MAX_VQ];
+        struct vhost_scsi_virtqueue vqs[VHOST_SCSI_MAX_VQ];
 
         struct vhost_work vs_completion_work; /* cmd completion work item */
         struct llist_head vs_completion_list; /* cmd completion queue */
@@ -366,7 +370,7 @@ static void tcm_vhost_free_evt(struct vhost_scsi *vs, struct tcm_vhost_evt *evt)
 static struct tcm_vhost_evt *tcm_vhost_allocate_evt(struct vhost_scsi *vs,
         u32 event, u32 reason)
 {
-        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
+        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
         struct tcm_vhost_evt *evt;
 
         if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
@@ -409,7 +413,7 @@ static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd)
 static void tcm_vhost_do_evt_work(struct vhost_scsi *vs,
         struct tcm_vhost_evt *evt)
 {
-        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
+        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
         struct virtio_scsi_event *event = &evt->event;
         struct virtio_scsi_event __user *eventp;
         unsigned out, in;
@@ -460,7 +464,7 @@ static void tcm_vhost_evt_work(struct vhost_work *work)
 {
         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
                                         vs_event_work);
-        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
+        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
         struct tcm_vhost_evt *evt;
         struct llist_node *llnode;
 
@@ -511,8 +515,10 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
                        v_rsp.sense_len);
                 ret = copy_to_user(tv_cmd->tvc_resp, &v_rsp, sizeof(v_rsp));
                 if (likely(ret == 0)) {
+                        struct vhost_scsi_virtqueue *q;
                         vhost_add_used(tv_cmd->tvc_vq, tv_cmd->tvc_vq_desc, 0);
-                        vq = tv_cmd->tvc_vq - vs->vqs;
+                        q = container_of(tv_cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
+                        vq = q - vs->vqs;
                         __set_bit(vq, signal);
                 } else
                         pr_err("Faulted on virtio_scsi_cmd_resp\n");
@@ -523,7 +529,7 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
         vq = -1;
         while ((vq = find_next_bit(signal, VHOST_SCSI_MAX_VQ, vq + 1))
                 < VHOST_SCSI_MAX_VQ)
-                vhost_signal(&vs->dev, &vs->vqs[vq]);
+                vhost_signal(&vs->dev, &vs->vqs[vq].vq);
 }
 
 static struct tcm_vhost_cmd *vhost_scsi_allocate_cmd(
@@ -938,7 +944,7 @@ static void vhost_scsi_handle_kick(struct vhost_work *work)
 
 static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
 {
-        vhost_poll_flush(&vs->dev.vqs[index].poll);
+        vhost_poll_flush(&vs->vqs[index].vq.poll);
 }
 
 static void vhost_scsi_flush(struct vhost_scsi *vs)
@@ -975,7 +981,7 @@ static int vhost_scsi_set_endpoint(
         /* Verify that ring has been setup correctly. */
         for (index = 0; index < vs->dev.nvqs; ++index) {
                 /* Verify that ring has been setup correctly. */
-                if (!vhost_vq_access_ok(&vs->vqs[index])) {
+                if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
                         ret = -EFAULT;
                         goto out;
                 }
@@ -1022,7 +1028,7 @@ static int vhost_scsi_set_endpoint(
                 memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
                        sizeof(vs->vs_vhost_wwpn));
                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
-                        vq = &vs->vqs[i];
+                        vq = &vs->vqs[i].vq;
                         /* Flushing the vhost_work acts as synchronize_rcu */
                         mutex_lock(&vq->mutex);
                         rcu_assign_pointer(vq->private_data, vs_tpg);
@@ -1063,7 +1069,7 @@ static int vhost_scsi_clear_endpoint(
         mutex_lock(&vs->dev.mutex);
         /* Verify that ring has been setup correctly. */
         for (index = 0; index < vs->dev.nvqs; ++index) {
-                if (!vhost_vq_access_ok(&vs->vqs[index])) {
+                if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
                         ret = -EFAULT;
                         goto err_dev;
                 }
@@ -1103,7 +1109,7 @@ static int vhost_scsi_clear_endpoint(
         }
         if (match) {
                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
-                        vq = &vs->vqs[i];
+                        vq = &vs->vqs[i].vq;
                         /* Flushing the vhost_work acts as synchronize_rcu */
                         mutex_lock(&vq->mutex);
                         rcu_assign_pointer(vq->private_data, NULL);
@@ -1151,24 +1157,36 @@ static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
 static int vhost_scsi_open(struct inode *inode, struct file *f)
 {
         struct vhost_scsi *s;
+        struct vhost_virtqueue **vqs;
         int r, i;
 
         s = kzalloc(sizeof(*s), GFP_KERNEL);
         if (!s)
                 return -ENOMEM;
 
+        vqs = kmalloc(VHOST_SCSI_MAX_VQ * sizeof(*vqs), GFP_KERNEL);
+        if (!vqs) {
+                kfree(s);
+                return -ENOMEM;
+        }
+
         vhost_work_init(&s->vs_completion_work, vhost_scsi_complete_cmd_work);
         vhost_work_init(&s->vs_event_work, tcm_vhost_evt_work);
 
         s->vs_events_nr = 0;
         s->vs_events_missed = false;
 
-        s->vqs[VHOST_SCSI_VQ_CTL].handle_kick = vhost_scsi_ctl_handle_kick;
-        s->vqs[VHOST_SCSI_VQ_EVT].handle_kick = vhost_scsi_evt_handle_kick;
-        for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++)
-                s->vqs[i].handle_kick = vhost_scsi_handle_kick;
-        r = vhost_dev_init(&s->dev, s->vqs, VHOST_SCSI_MAX_VQ);
+        vqs[VHOST_SCSI_VQ_CTL] = &s->vqs[VHOST_SCSI_VQ_CTL].vq;
+        vqs[VHOST_SCSI_VQ_EVT] = &s->vqs[VHOST_SCSI_VQ_EVT].vq;
+        s->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
+        s->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
+        for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
+                vqs[i] = &s->vqs[i].vq;
+                s->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
+        }
+        r = vhost_dev_init(&s->dev, vqs, VHOST_SCSI_MAX_VQ);
         if (r < 0) {
+                kfree(vqs);
                 kfree(s);
                 return r;
         }
@@ -1190,6 +1208,7 @@ static int vhost_scsi_release(struct inode *inode, struct file *f)
         vhost_dev_cleanup(&s->dev, false);
         /* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
         vhost_scsi_flush(s);
+        kfree(s->dev.vqs);
         kfree(s);
         return 0;
 }
@@ -1205,7 +1224,7 @@ static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
         u32 events_missed;
         u64 features;
         int r, abi_version = VHOST_SCSI_ABI_VERSION;
-        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
+        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 
         switch (ioctl) {
         case VHOST_SCSI_SET_ENDPOINT:
@@ -1333,7 +1352,7 @@ static void tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
         else
                 reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
 
-        vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
+        vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
         mutex_lock(&vq->mutex);
         tcm_vhost_send_evt(vs, tpg, lun,
                         VIRTIO_SCSI_T_TRANSPORT_RESET, reason);