Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio updates from Rusty Russell:
 "Main excitement is a virtio_scsi fix for alloc holding spinlock on the
  abort path, which I refuse to CC stable since (1) I discovered it
  myself, and (2) it's been there forever with no reports"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio_scsi: don't call virtqueue_add_sgs(... GFP_NOIO) holding spinlock.
  virtio-rng: fixes for device registration/unregistration
  virtio-rng: fix boot with virtio-rng device
  virtio-rng: support multiple virtio-rng devices
  virtio_ccw: introduce device_lost in virtio_ccw_device
  virtio: virtio_break_device() to mark all virtqueues broken.

5 files changed, 127 insertions, 59 deletions

diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 2ce0e225e58c..f3e71501de54 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -25,88 +25,115 @@
 #include <linux/virtio_rng.h>
 #include <linux/module.h>
 
-static struct virtqueue *vq;
-static unsigned int data_avail;
-static DECLARE_COMPLETION(have_data);
-static bool busy;
+static DEFINE_IDA(rng_index_ida);
+
+struct virtrng_info {
+        struct virtio_device *vdev;
+        struct hwrng hwrng;
+        struct virtqueue *vq;
+        unsigned int data_avail;
+        struct completion have_data;
+        bool busy;
+        char name[25];
+        int index;
+};
 
 static void random_recv_done(struct virtqueue *vq)
 {
+        struct virtrng_info *vi = vq->vdev->priv;
+
         /* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
-        if (!virtqueue_get_buf(vq, &data_avail))
+        if (!virtqueue_get_buf(vi->vq, &vi->data_avail))
                 return;
 
-        complete(&have_data);
+        complete(&vi->have_data);
 }
 
 /* The host will fill any buffer we give it with sweet, sweet randomness. */
-static void register_buffer(u8 *buf, size_t size)
+static void register_buffer(struct virtrng_info *vi, u8 *buf, size_t size)
 {
         struct scatterlist sg;
 
         sg_init_one(&sg, buf, size);
 
         /* There should always be room for one buffer. */
-        virtqueue_add_inbuf(vq, &sg, 1, buf, GFP_KERNEL);
+        virtqueue_add_inbuf(vi->vq, &sg, 1, buf, GFP_KERNEL);
 
-        virtqueue_kick(vq);
+        virtqueue_kick(vi->vq);
 }
 
 static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
 {
         int ret;
+        struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
 
-        if (!busy) {
-                busy = true;
-                init_completion(&have_data);
-                register_buffer(buf, size);
+        if (!vi->busy) {
+                vi->busy = true;
+                init_completion(&vi->have_data);
+                register_buffer(vi, buf, size);
         }
 
         if (!wait)
                 return 0;
 
-        ret = wait_for_completion_killable(&have_data);
+        ret = wait_for_completion_killable(&vi->have_data);
         if (ret < 0)
                 return ret;
 
-        busy = false;
+        vi->busy = false;
 
-        return data_avail;
+        return vi->data_avail;
 }
 
 static void virtio_cleanup(struct hwrng *rng)
 {
-        if (busy)
-                wait_for_completion(&have_data);
-}
+        struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
 
-
-static struct hwrng virtio_hwrng = {
-        .name           = "virtio",
-        .cleanup        = virtio_cleanup,
-        .read           = virtio_read,
-};
+        if (vi->busy)
+                wait_for_completion(&vi->have_data);
+}
 
 static int probe_common(struct virtio_device *vdev)
 {
-        int err;
+        int err, index;
+        struct virtrng_info *vi = NULL;
+
+        vi = kzalloc(sizeof(struct virtrng_info), GFP_KERNEL);
+        if (!vi)
+                return -ENOMEM;
 
-        if (vq) {
-                /* We only support one device for now */
-                return -EBUSY;
+        vi->index = index = ida_simple_get(&rng_index_ida, 0, 0, GFP_KERNEL);
+        if (index < 0) {
+                kfree(vi);
+                return index;
         }
+        sprintf(vi->name, "virtio_rng.%d", index);
+        init_completion(&vi->have_data);
+
+        vi->hwrng = (struct hwrng) {
+                .read = virtio_read,
+                .cleanup = virtio_cleanup,
+                .priv = (unsigned long)vi,
+                .name = vi->name,
+        };
+        vdev->priv = vi;
+
         /* We expect a single virtqueue. */
-        vq = virtio_find_single_vq(vdev, random_recv_done, "input");
-        if (IS_ERR(vq)) {
-                err = PTR_ERR(vq);
-                vq = NULL;
+        vi->vq = virtio_find_single_vq(vdev, random_recv_done, "input");
+        if (IS_ERR(vi->vq)) {
+                err = PTR_ERR(vi->vq);
+                vi->vq = NULL;
+                kfree(vi);
+                ida_simple_remove(&rng_index_ida, index);
                 return err;
         }
 
-        err = hwrng_register(&virtio_hwrng);
+        err = hwrng_register(&vi->hwrng);
         if (err) {
                 vdev->config->del_vqs(vdev);
-                vq = NULL;
+                vi->vq = NULL;
+                kfree(vi);
+                ida_simple_remove(&rng_index_ida, index);
                 return err;
         }
 
@@ -115,11 +142,13 @@ static int probe_common(struct virtio_device *vdev)
 
 static void remove_common(struct virtio_device *vdev)
 {
+        struct virtrng_info *vi = vdev->priv;
         vdev->config->reset(vdev);
-        busy = false;
-        hwrng_unregister(&virtio_hwrng);
+        vi->busy = false;
+        hwrng_unregister(&vi->hwrng);
         vdev->config->del_vqs(vdev);
-        vq = NULL;
+        ida_simple_remove(&rng_index_ida, vi->index);
+        kfree(vi);
 }
 
 static int virtrng_probe(struct virtio_device *vdev)
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 1e1fc671f89a..d2c0b442bce5 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/kvm_para.h>
+#include <linux/notifier.h>
 #include <asm/setup.h>
 #include <asm/irq.h>
 #include <asm/cio.h>
@@ -62,6 +63,7 @@ struct virtio_ccw_device {
         struct vq_config_block *config_block;
         bool is_thinint;
         bool going_away;
+        bool device_lost;
         void *airq_info;
 };
 
@@ -1010,11 +1012,14 @@ static void virtio_ccw_remove(struct ccw_device *cdev)
         unsigned long flags;
         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
 
-        if (vcdev && cdev->online)
+        if (vcdev && cdev->online) {
+                if (vcdev->device_lost)
+                        virtio_break_device(&vcdev->vdev);
                 unregister_virtio_device(&vcdev->vdev);
-        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
-        dev_set_drvdata(&cdev->dev, NULL);
-        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+                spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+                dev_set_drvdata(&cdev->dev, NULL);
+                spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+        }
         cdev->handler = NULL;
 }
 
@@ -1023,12 +1028,14 @@ static int virtio_ccw_offline(struct ccw_device *cdev)
         unsigned long flags;
         struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
 
-        if (vcdev) {
-                unregister_virtio_device(&vcdev->vdev);
-                spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
-                dev_set_drvdata(&cdev->dev, NULL);
-                spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
-        }
+        if (!vcdev)
+                return 0;
+        if (vcdev->device_lost)
+                virtio_break_device(&vcdev->vdev);
+        unregister_virtio_device(&vcdev->vdev);
+        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+        dev_set_drvdata(&cdev->dev, NULL);
+        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
         return 0;
 }
 
@@ -1096,8 +1103,26 @@ out_free:
 
 static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
 {
-        /* TODO: Check whether we need special handling here. */
-        return 0;
+        int rc;
+        struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
+
+        /*
+         * Make sure vcdev is set
+         * i.e. set_offline/remove callback not already running
+         */
+        if (!vcdev)
+                return NOTIFY_DONE;
+
+        switch (event) {
+        case CIO_GONE:
+                vcdev->device_lost = true;
+                rc = NOTIFY_DONE;
+                break;
+        default:
+                rc = NOTIFY_DONE;
+                break;
+        }
+        return rc;
 }
 
 static struct ccw_device_id virtio_ids[] = {
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index d4727b339474..99fdb9403944 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -393,11 +393,10 @@ static void virtscsi_event_done(struct virtqueue *vq)
  * @cmd         : command structure
  * @req_size    : size of the request buffer
  * @resp_size   : size of the response buffer
- * @gfp : flags to use for memory allocations
  */
 static int virtscsi_add_cmd(struct virtqueue *vq,
                             struct virtio_scsi_cmd *cmd,
-                            size_t req_size, size_t resp_size, gfp_t gfp)
+                            size_t req_size, size_t resp_size)
 {
         struct scsi_cmnd *sc = cmd->sc;
         struct scatterlist *sgs[4], req, resp;
@@ -429,19 +428,19 @@ static int virtscsi_add_cmd(struct virtqueue *vq,
         if (in)
                 sgs[out_num + in_num++] = in->sgl;
 
-        return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
+        return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC);
 }
 
 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
                              struct virtio_scsi_cmd *cmd,
-                             size_t req_size, size_t resp_size, gfp_t gfp)
+                             size_t req_size, size_t resp_size)
 {
         unsigned long flags;
         int err;
         bool needs_kick = false;
 
         spin_lock_irqsave(&vq->vq_lock, flags);
-        err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp);
+        err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size);
         if (!err)
                 needs_kick = virtqueue_kick_prepare(vq->vq);
 
@@ -484,8 +483,7 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
         memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
 
         if (virtscsi_kick_cmd(req_vq, cmd,
-                              sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
-                              GFP_ATOMIC) != 0)
+                              sizeof cmd->req.cmd, sizeof cmd->resp.cmd) != 0)
                 return SCSI_MLQUEUE_HOST_BUSY;
         return 0;
 }
@@ -542,8 +540,7 @@ static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
 
         cmd->comp = &comp;
         if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
-                              sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
-                              GFP_NOIO) < 0)
+                              sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0)
                 goto out;
 
         wait_for_completion(&comp);
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1e443629f76d..4d08f45a9c29 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -865,4 +865,19 @@ bool virtqueue_is_broken(struct virtqueue *_vq)
 }
 EXPORT_SYMBOL_GPL(virtqueue_is_broken);
 
+/*
+ * This should prevent the device from being used, allowing drivers to
+ * recover.  You may need to grab appropriate locks to flush.
+ */
+void virtio_break_device(struct virtio_device *dev)
+{
+        struct virtqueue *_vq;
+
+        list_for_each_entry(_vq, &dev->vqs, list) {
+                struct vring_virtqueue *vq = to_vvq(_vq);
+                vq->broken = true;
+        }
+}
+EXPORT_SYMBOL_GPL(virtio_break_device);
+
 MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index e4abb84199be..b46671e28de2 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -106,6 +106,8 @@ static inline struct virtio_device *dev_to_virtio(struct device *_dev)
 int register_virtio_device(struct virtio_device *dev);
 void unregister_virtio_device(struct virtio_device *dev);
 
+void virtio_break_device(struct virtio_device *dev);
+
 /**
  * virtio_driver - operations for a virtio I/O driver
  * @driver: underlying device driver (populate name and owner).