KVM: s390: Dynamic allocation of virtio-ccw I/O data.

Dynamically allocate any data structures like ccw used when
doing channel I/O. Otherwise, we'd need to add extra serialization
for the different callbacks using the same data structures.

Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 174 insertions, 106 deletions

diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 1a5aff31d752..70419a75d0e0 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -46,11 +46,9 @@ struct vq_config_block {
 
 struct virtio_ccw_device {
         struct virtio_device vdev;
-        __u8 status;
+        __u8 *status;
         __u8 config[VIRTIO_CCW_CONFIG_SIZE];
         struct ccw_device *cdev;
-        struct ccw1 *ccw;
-        __u32 area;
         __u32 curr_io;
         int err;
         wait_queue_head_t wait_q;
@@ -127,14 +125,15 @@ static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
         return ret;
 }
 
-static int ccw_io_helper(struct virtio_ccw_device *vcdev, __u32 intparm)
+static int ccw_io_helper(struct virtio_ccw_device *vcdev,
+                         struct ccw1 *ccw, __u32 intparm)
 {
         int ret;
         unsigned long flags;
         int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
 
         spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
-        ret = ccw_device_start(vcdev->cdev, vcdev->ccw, intparm, 0, 0);
+        ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
         if (!ret)
                 vcdev->curr_io |= flag;
         spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
@@ -167,18 +166,19 @@ static void virtio_ccw_kvm_notify(struct virtqueue *vq)
         do_kvm_notify(schid, virtqueue_get_queue_index(vq));
 }
 
-static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, int index)
+static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
+                                   struct ccw1 *ccw, int index)
 {
         vcdev->config_block->index = index;
-        vcdev->ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = sizeof(struct vq_config_block);
-        vcdev->ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
-        ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_VQ_CONF);
+        ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
+        ccw->flags = 0;
+        ccw->count = sizeof(struct vq_config_block);
+        ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
+        ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
         return vcdev->config_block->num;
 }
 
-static void virtio_ccw_del_vq(struct virtqueue *vq)
+static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
         struct virtio_ccw_vq_info *info = vq->priv;
@@ -197,11 +197,12 @@ static void virtio_ccw_del_vq(struct virtqueue *vq)
         info->info_block->align = 0;
         info->info_block->index = index;
         info->info_block->num = 0;
-        vcdev->ccw->cmd_code = CCW_CMD_SET_VQ;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = sizeof(*info->info_block);
-        vcdev->ccw->cda = (__u32)(unsigned long)(info->info_block);
-        ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | index);
+        ccw->cmd_code = CCW_CMD_SET_VQ;
+        ccw->flags = 0;
+        ccw->count = sizeof(*info->info_block);
+        ccw->cda = (__u32)(unsigned long)(info->info_block);
+        ret = ccw_io_helper(vcdev, ccw,
+                            VIRTIO_CCW_DOING_SET_VQ | index);
         /*
          * -ENODEV isn't considered an error: The device is gone anyway.
          * This may happen on device detach.
@@ -220,14 +221,23 @@ static void virtio_ccw_del_vq(struct virtqueue *vq)
 static void virtio_ccw_del_vqs(struct virtio_device *vdev)
 {
         struct virtqueue *vq, *n;
+        struct ccw1 *ccw;
+
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return;
+
 
         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
-                virtio_ccw_del_vq(vq);
+                virtio_ccw_del_vq(vq, ccw);
+
+        kfree(ccw);
 }
 
 static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
                                              int i, vq_callback_t *callback,
-                                             const char *name)
+                                             const char *name,
+                                             struct ccw1 *ccw)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
         int err;
@@ -250,7 +260,7 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
                 err = -ENOMEM;
                 goto out_err;
         }
-        info->num = virtio_ccw_read_vq_conf(vcdev, i);
+        info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
         size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
         info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
         if (info->queue == NULL) {
@@ -277,11 +287,11 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
         info->info_block->align = KVM_VIRTIO_CCW_RING_ALIGN;
         info->info_block->index = i;
         info->info_block->num = info->num;
-        vcdev->ccw->cmd_code = CCW_CMD_SET_VQ;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = sizeof(*info->info_block);
-        vcdev->ccw->cda = (__u32)(unsigned long)(info->info_block);
-        err = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | i);
+        ccw->cmd_code = CCW_CMD_SET_VQ;
+        ccw->flags = 0;
+        ccw->count = sizeof(*info->info_block);
+        ccw->cda = (__u32)(unsigned long)(info->info_block);
+        err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
         if (err) {
                 dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
                 free_pages_exact(info->queue, size);
@@ -312,9 +322,15 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
         unsigned long *indicatorp = NULL;
         int ret, i;
+        struct ccw1 *ccw;
+
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return -ENOMEM;
 
         for (i = 0; i < nvqs; ++i) {
-                vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i]);
+                vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
+                                             ccw);
                 if (IS_ERR(vqs[i])) {
                         ret = PTR_ERR(vqs[i]);
                         vqs[i] = NULL;
@@ -329,28 +345,30 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
         *indicatorp = (unsigned long) &vcdev->indicators;
         /* Register queue indicators with host. */
         vcdev->indicators = 0;
-        vcdev->ccw->cmd_code = CCW_CMD_SET_IND;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = sizeof(vcdev->indicators);
-        vcdev->ccw->cda = (__u32)(unsigned long) indicatorp;
-        ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_IND);
+        ccw->cmd_code = CCW_CMD_SET_IND;
+        ccw->flags = 0;
+        ccw->count = sizeof(vcdev->indicators);
+        ccw->cda = (__u32)(unsigned long) indicatorp;
+        ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
         if (ret)
                 goto out;
         /* Register indicators2 with host for config changes */
         *indicatorp = (unsigned long) &vcdev->indicators2;
         vcdev->indicators2 = 0;
-        vcdev->ccw->cmd_code = CCW_CMD_SET_CONF_IND;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = sizeof(vcdev->indicators2);
-        vcdev->ccw->cda = (__u32)(unsigned long) indicatorp;
-        ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_CONF_IND);
+        ccw->cmd_code = CCW_CMD_SET_CONF_IND;
+        ccw->flags = 0;
+        ccw->count = sizeof(vcdev->indicators2);
+        ccw->cda = (__u32)(unsigned long) indicatorp;
+        ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
         if (ret)
                 goto out;
 
         kfree(indicatorp);
+        kfree(ccw);
         return 0;
 out:
         kfree(indicatorp);
+        kfree(ccw);
         virtio_ccw_del_vqs(vdev);
         return ret;
 }
@@ -358,64 +376,95 @@ out:
 static void virtio_ccw_reset(struct virtio_device *vdev)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+        struct ccw1 *ccw;
+
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return;
 
         /* Zero status bits. */
-        vcdev->status = 0;
+        *vcdev->status = 0;
 
         /* Send a reset ccw on device. */
-        vcdev->ccw->cmd_code = CCW_CMD_VDEV_RESET;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = 0;
-        vcdev->ccw->cda = 0;
-        ccw_io_helper(vcdev, VIRTIO_CCW_DOING_RESET);
+        ccw->cmd_code = CCW_CMD_VDEV_RESET;
+        ccw->flags = 0;
+        ccw->count = 0;
+        ccw->cda = 0;
+        ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
+        kfree(ccw);
 }
 
 static u32 virtio_ccw_get_features(struct virtio_device *vdev)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
-        struct virtio_feature_desc features;
-        int ret;
+        struct virtio_feature_desc *features;
+        int ret, rc;
+        struct ccw1 *ccw;
 
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return 0;
+
+        features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
+        if (!features) {
+                rc = 0;
+                goto out_free;
+        }
         /* Read the feature bits from the host. */
         /* TODO: Features > 32 bits */
-        features.index = 0;
-        vcdev->ccw->cmd_code = CCW_CMD_READ_FEAT;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = sizeof(features);
-        vcdev->ccw->cda = vcdev->area;
-        ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_FEAT);
-        if (ret)
-                return 0;
+        features->index = 0;
+        ccw->cmd_code = CCW_CMD_READ_FEAT;
+        ccw->flags = 0;
+        ccw->count = sizeof(*features);
+        ccw->cda = (__u32)(unsigned long)features;
+        ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
+        if (ret) {
+                rc = 0;
+                goto out_free;
+        }
+
+        rc = le32_to_cpu(features->features);
 
-        memcpy(&features, (void *)(unsigned long)vcdev->area,
-               sizeof(features));
-        return le32_to_cpu(features.features);
+out_free:
+        kfree(features);
+        kfree(ccw);
+        return rc;
 }
 
 static void virtio_ccw_finalize_features(struct virtio_device *vdev)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
-        struct virtio_feature_desc features;
+        struct virtio_feature_desc *features;
         int i;
+        struct ccw1 *ccw;
+
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return;
+
+        features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
+        if (!features)
+                goto out_free;
 
         /* Give virtio_ring a chance to accept features. */
         vring_transport_features(vdev);
 
-        for (i = 0; i < sizeof(*vdev->features) / sizeof(features.features);
+        for (i = 0; i < sizeof(*vdev->features) / sizeof(features->features);
              i++) {
                 int highbits = i % 2 ? 32 : 0;
-                features.index = i;
-                features.features = cpu_to_le32(vdev->features[i / 2]
-                                                >> highbits);
-                memcpy((void *)(unsigned long)vcdev->area, &features,
-                       sizeof(features));
+                features->index = i;
+                features->features = cpu_to_le32(vdev->features[i / 2]
+                                                 >> highbits);
                 /* Write the feature bits to the host. */
-                vcdev->ccw->cmd_code = CCW_CMD_WRITE_FEAT;
-                vcdev->ccw->flags = 0;
-                vcdev->ccw->count = sizeof(features);
-                vcdev->ccw->cda = vcdev->area;
-                ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_FEAT);
+                ccw->cmd_code = CCW_CMD_WRITE_FEAT;
+                ccw->flags = 0;
+                ccw->count = sizeof(*features);
+                ccw->cda = (__u32)(unsigned long)features;
+                ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
         }
+out_free:
+        kfree(features);
+        kfree(ccw);
 }
 
 static void virtio_ccw_get_config(struct virtio_device *vdev,
@@ -423,19 +472,32 @@ static void virtio_ccw_get_config(struct virtio_device *vdev,
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
         int ret;
+        struct ccw1 *ccw;
+        void *config_area;
+
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return;
+
+        config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
+        if (!config_area)
+                goto out_free;
 
         /* Read the config area from the host. */
-        vcdev->ccw->cmd_code = CCW_CMD_READ_CONF;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = offset + len;
-        vcdev->ccw->cda = vcdev->area;
-        ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_CONFIG);
+        ccw->cmd_code = CCW_CMD_READ_CONF;
+        ccw->flags = 0;
+        ccw->count = offset + len;
+        ccw->cda = (__u32)(unsigned long)config_area;
+        ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
         if (ret)
-                return;
+                goto out_free;
 
-        memcpy(vcdev->config, (void *)(unsigned long)vcdev->area,
-               sizeof(vcdev->config));
+        memcpy(vcdev->config, config_area, sizeof(vcdev->config));
         memcpy(buf, &vcdev->config[offset], len);
+
+out_free:
+        kfree(config_area);
+        kfree(ccw);
 }
 
 static void virtio_ccw_set_config(struct virtio_device *vdev,
@@ -443,37 +505,55 @@ static void virtio_ccw_set_config(struct virtio_device *vdev,
                                   unsigned len)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+        struct ccw1 *ccw;
+        void *config_area;
+
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return;
+
+        config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
+        if (!config_area)
+                goto out_free;
 
         memcpy(&vcdev->config[offset], buf, len);
         /* Write the config area to the host. */
-        memcpy((void *)(unsigned long)vcdev->area, vcdev->config,
-               sizeof(vcdev->config));
-        vcdev->ccw->cmd_code = CCW_CMD_WRITE_CONF;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = offset + len;
-        vcdev->ccw->cda = vcdev->area;
-        ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_CONFIG);
+        memcpy(config_area, vcdev->config, sizeof(vcdev->config));
+        ccw->cmd_code = CCW_CMD_WRITE_CONF;
+        ccw->flags = 0;
+        ccw->count = offset + len;
+        ccw->cda = (__u32)(unsigned long)config_area;
+        ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
+
+out_free:
+        kfree(config_area);
+        kfree(ccw);
 }
 
 static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
 
-        return vcdev->status;
+        return *vcdev->status;
 }
 
 static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 {
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+        struct ccw1 *ccw;
+
+        ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
+        if (!ccw)
+                return;
 
         /* Write the status to the host. */
-        vcdev->status = status;
-        memcpy((void *)(unsigned long)vcdev->area, &status, sizeof(status));
-        vcdev->ccw->cmd_code = CCW_CMD_WRITE_STATUS;
-        vcdev->ccw->flags = 0;
-        vcdev->ccw->count = sizeof(status);
-        vcdev->ccw->cda = vcdev->area;
-        ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_STATUS);
+        *vcdev->status = status;
+        ccw->cmd_code = CCW_CMD_WRITE_STATUS;
+        ccw->flags = 0;
+        ccw->count = sizeof(status);
+        ccw->cda = (__u32)(unsigned long)vcdev->status;
+        ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
+        kfree(ccw);
 }
 
 static struct virtio_config_ops virtio_ccw_config_ops = {
@@ -499,9 +579,8 @@ static void virtio_ccw_release_dev(struct device *_d)
                                                  dev);
         struct virtio_ccw_device *vcdev = to_vc_device(dev);
 
-        kfree((void *)(unsigned long)vcdev->area);
+        kfree(vcdev->status);
         kfree(vcdev->config_block);
-        kfree(vcdev->ccw);
         kfree(vcdev);
 }
 
@@ -657,9 +736,6 @@ static int virtio_ccw_offline(struct ccw_device *cdev)
 }
 
 
-/* Area needs to be big enough to fit status, features or configuration. */
-#define VIRTIO_AREA_SIZE VIRTIO_CCW_CONFIG_SIZE /* biggest possible use */
-
 static int virtio_ccw_online(struct ccw_device *cdev)
 {
         int ret;
@@ -671,21 +747,14 @@ static int virtio_ccw_online(struct ccw_device *cdev)
                 ret = -ENOMEM;
                 goto out_free;
         }
-        vcdev->area = (__u32)(unsigned long)kzalloc(VIRTIO_AREA_SIZE,
-                                                    GFP_DMA | GFP_KERNEL);
-        if (!vcdev->area) {
-                dev_warn(&cdev->dev, "Cound not get memory for virtio\n");
-                ret = -ENOMEM;
-                goto out_free;
-        }
         vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),
                                    GFP_DMA | GFP_KERNEL);
         if (!vcdev->config_block) {
                 ret = -ENOMEM;
                 goto out_free;
         }
-        vcdev->ccw = kzalloc(sizeof(*vcdev->ccw), GFP_DMA | GFP_KERNEL);
-        if (!vcdev->ccw) {
+        vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
+        if (!vcdev->status) {
                 ret = -ENOMEM;
                 goto out_free;
         }
@@ -714,9 +783,8 @@ out_put:
         return ret;
 out_free:
         if (vcdev) {
-                kfree((void *)(unsigned long)vcdev->area);
+                kfree(vcdev->status);
                 kfree(vcdev->config_block);
-                kfree(vcdev->ccw);
         }
         kfree(vcdev);
         return ret;