[Qemu-devel] [PATCH 2/2] fix virtio_blk serial pci config breakage

[john cooper]

Change virtblk_identify() to pull ATA identify
data from the bar #5 map vs. the pci config
area.  Add minimal support for bar mapping external
to virtio/virtio_pci.c.

Signed-off-by: john cooper <address@hidden>
---

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index aa1a3d5..a1687f3 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -8,6 +8,8 @@
 
 #define PART_BITS 4
 
+#define VBLK_IDENTIFY_BAR 5    /* PCI BAR #5 maps identify/config area */
+
 static int major, index;
 
 struct virtio_blk
@@ -25,6 +27,9 @@ struct virtio_blk
 
        mempool_t *pool;
 
+       /* maintains mapping of pci bar #5 unique to virtio_blk */
+       void __iomem *identify_ioaddr;
+
        /* What host tells us, plus 2 for header & tailer. */
        unsigned int sg_elems;
 
@@ -171,24 +176,30 @@ static void do_virtblk_request(struct request_queue *q)
                vblk->vq->vq_ops->kick(vblk->vq);
 }
 
-/* return ATA identify data
+/* return ATA identify data if supported by virtio_blk device
  */
 static int virtblk_identify(struct gendisk *disk, void *argp)
 {
        struct virtio_blk *vblk = disk->private_data;
        void *opaque;
-       int err = -ENOMEM;
+       int err, i;
+       char *p;
 
+       err = 0;
        opaque = kmalloc(VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
-       if (!opaque)
+       if (!opaque) {
+               err = -ENOMEM;
                goto out;
+       }
 
-       err = virtio_config_buf(vblk->vdev, VIRTIO_BLK_F_IDENTIFY,
-               offsetof(struct virtio_blk_config, identify), opaque,
-               VIRTIO_BLK_ID_BYTES);
-
-       if (err)
+       if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_IDENTIFY) ||
+           !vblk->identify_ioaddr) {
+               err = -ENOENT;
                goto out_kfree;
+       }
+
+       for (p = opaque, i = 0; i < VIRTIO_BLK_ID_BYTES; ++i)
+               *p++ = ioread8(vblk->identify_ioaddr + i);
 
        if (copy_to_user(argp, opaque, VIRTIO_BLK_ID_BYTES))
                err = -EFAULT;
@@ -383,6 +394,9 @@ static int __devinit virtblk_probe(struct virtio_device 
*vdev)
        if (!err)
                blk_queue_logical_block_size(vblk->disk->queue, blk_size);
 
+       vblk->identify_ioaddr = vdev->config->map ?
+               vdev->config->map(vdev, VBLK_IDENTIFY_BAR, 0) : NULL;
+
        add_disk(vblk->disk);
        return 0;
 
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 248e00e..abc6963 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -561,6 +561,13 @@ static int vp_find_vqs(struct virtio_device *vdev, 
unsigned nvqs,
        return err;
 }
 
+/* translate struct virtio_device to struct pci_dev, setup map for bar
+ */
+void __iomem *vp_map(struct virtio_device *vdev, int bar, unsigned long maxlen)
+{
+        return pci_iomap(to_vp_device(vdev)->pci_dev, bar, maxlen);
+}
+
 static struct virtio_config_ops virtio_pci_config_ops = {
        .get            = vp_get,
        .set            = vp_set,
@@ -571,6 +578,7 @@ static struct virtio_config_ops virtio_pci_config_ops = {
        .del_vqs        = vp_del_vqs,
        .get_features   = vp_get_features,
        .finalize_features = vp_finalize_features,
+       .map            = vp_map, 
 };
 
 static void virtio_pci_release_dev(struct device *_d)
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index e547e3c..b9b3c62 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -94,6 +94,8 @@ struct virtio_config_ops {
        void (*del_vqs)(struct virtio_device *);
        u32 (*get_features)(struct virtio_device *vdev);
        void (*finalize_features)(struct virtio_device *vdev);
+       void __iomem *(*map)(struct virtio_device *vdev, int bar,
+                                   unsigned long maxlen);
 };
 
 /* If driver didn't advertise the feature, it will never appear. */


-- 
address@hidden