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>

diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 1a5aff3..70419a7 100644 (file)
--- 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;