[SLOF] [PATCH v3 20/22] virtio-blk: enable virtio 1.0

[Nikunj A Dadhania]

Signed-off-by: Nikunj A Dadhania <nikunj at linux.vnet.ibm.com>
---
 lib/libvirtio/virtio-blk.c | 65 ++++++++++++++++++++++++++++++----------------
 1 file changed, 42 insertions(+), 23 deletions(-)

diff --git a/lib/libvirtio/virtio-blk.c b/lib/libvirtio/virtio-blk.c
index 83c3244..1ab5dcd 100644
--- a/lib/libvirtio/virtio-blk.c
+++ b/lib/libvirtio/virtio-blk.c
@@ -18,6 +18,7 @@
 #include "virtio-blk.h"
 
 #define DEFAULT_SECTOR_SIZE 512
+#define DRIVER_FEATURE_SUPPORT  (VIRTIO_BLK_F_BLK_SIZE | VIRTIO_F_VERSION_1)
 
 static struct vqs vq;
 
@@ -33,9 +34,6 @@ virtioblk_init(struct virtio_device *dev)
 	int features;
 	int status = VIRTIO_STAT_ACKNOWLEDGE;
 
-	/* Keep it disabled until the driver is 1.0 capable */
-	dev->is_modern = false;
-
 	/* Reset device */
 	virtio_reset_device(dev);
 
@@ -46,28 +44,44 @@ virtioblk_init(struct virtio_device *dev)
 	status |= VIRTIO_STAT_DRIVER;
 	virtio_set_status(dev, status);
 
-	/* Device specific setup - we support F_BLK_SIZE */
-	virtio_set_guest_features(dev,  VIRTIO_BLK_F_BLK_SIZE);
+	if (dev->is_modern) {
+		uint64_t features;
+		/* Negotiate features and sets FEATURES_OK if successful */
+		if (virtio_negotiate_guest_features(dev, DRIVER_FEATURE_SUPPORT))
+			goto dev_error;
+
+		virtio_get_status(dev, &status);
+		virtio_get_host_features_long(dev, &features);
+		if (features & VIRTIO_BLK_F_BLK_SIZE) {
+			blk_size = virtio_get_config(dev,
+						     offset_of(struct virtio_blk_cfg, blk_size),
+						     sizeof(blk_size));
+		}
+	} else {
+		/* Device specific setup - we support F_BLK_SIZE */
+		virtio_set_guest_features(dev,  VIRTIO_BLK_F_BLK_SIZE);
+
+		virtio_get_host_features(dev, &features);
+		if (features & VIRTIO_BLK_F_BLK_SIZE) {
+			blk_size = virtio_get_config(dev,
+						     offset_of(struct virtio_blk_cfg, blk_size),
+						     sizeof(blk_size));
+		}
+	}
 
 	if (virtio_queue_init_vq(dev, &vq, 0))
 		goto dev_error;
 
 	vq_avail = virtio_get_vring_avail(dev, 0);
-	vq_avail->flags = VRING_AVAIL_F_NO_INTERRUPT;
+	vq_avail->flags = virtio_cpu_to_modern16(dev, VRING_AVAIL_F_NO_INTERRUPT);
 	vq_avail->idx = 0;
 
 	/* Tell HV that setup succeeded */
 	status |= VIRTIO_STAT_DRIVER_OK;
 	virtio_set_status(dev, status);
 
-	virtio_get_host_features(dev, &features);
-	if (features & VIRTIO_BLK_F_BLK_SIZE) {
-		blk_size = virtio_get_config(dev,
-				offset_of(struct virtio_blk_cfg, blk_size),
-				sizeof(blk_size));
-	}
-
 	return blk_size;
+
 dev_error:
 	printf("%s: failed\n", __func__);
 	status |= VIRTIO_STAT_FAILED;
@@ -126,7 +140,7 @@ virtioblk_read(struct virtio_device *dev, char *buf, long blocknum, long cnt)
 	struct vring_used *vq_used;		/* "Used" vring */
 	volatile uint8_t status = -1;
 	volatile uint16_t *current_used_idx;
-	uint16_t last_used_idx;
+	uint16_t last_used_idx, avail_idx;
 	int blk_size = DEFAULT_SECTOR_SIZE;
 
 	//printf("virtioblk_read: dev=%p buf=%p blocknum=%li count=%li\n",
@@ -154,33 +168,38 @@ virtioblk_read(struct virtio_device *dev, char *buf, long blocknum, long cnt)
 	vq_avail = virtio_get_vring_avail(dev, 0);
 	vq_used = virtio_get_vring_used(dev, 0);
 
+	avail_idx = virtio_modern16_to_cpu(dev, vq_avail->idx);
+
 	last_used_idx = vq_used->idx;
 	current_used_idx = &vq_used->idx;
 
 	/* Set up header */
-	fill_blk_hdr(&blkhdr, false, VIRTIO_BLK_T_IN | VIRTIO_BLK_T_BARRIER,
+	fill_blk_hdr(&blkhdr, dev->is_modern, VIRTIO_BLK_T_IN | VIRTIO_BLK_T_BARRIER,
 		     1, blocknum * blk_size / DEFAULT_SECTOR_SIZE);
 
 	/* Determine descriptor index */
-	id = (vq_avail->idx * 3) % vq_size;
+	id = (avail_idx * 3) % vq_size;
 
 	/* Set up virtqueue descriptor for header */
 	desc = &vq_desc[id];
-	virtio_fill_desc(desc, false, (uint64_t)&blkhdr, sizeof(struct virtio_blk_req),
-		  VRING_DESC_F_NEXT, (id + 1) % vq_size);
+	virtio_fill_desc(desc, dev->is_modern, (uint64_t)&blkhdr,
+			 sizeof(struct virtio_blk_req),
+			 VRING_DESC_F_NEXT, (id + 1) % vq_size);
 
 	/* Set up virtqueue descriptor for data */
 	desc = &vq_desc[(id + 1) % vq_size];
-	virtio_fill_desc(desc, false, (uint64_t)buf, cnt * blk_size,
-		  VRING_DESC_F_NEXT | VRING_DESC_F_WRITE, (id + 2) % vq_size);
+	virtio_fill_desc(desc, dev->is_modern, (uint64_t)buf, cnt * blk_size,
+			 VRING_DESC_F_NEXT | VRING_DESC_F_WRITE,
+			 (id + 2) % vq_size);
 
 	/* Set up virtqueue descriptor for status */
 	desc = &vq_desc[(id + 2) % vq_size];
-	virtio_fill_desc(desc, false, (uint64_t)&status, 1, VRING_DESC_F_WRITE, 0);
+	virtio_fill_desc(desc, dev->is_modern, (uint64_t)&status, 1,
+			 VRING_DESC_F_WRITE, 0);
 
-	vq_avail->ring[vq_avail->idx % vq_size] = id;
+	vq_avail->ring[avail_idx % vq_size] = virtio_cpu_to_modern16 (dev, id);
 	mb();
-	vq_avail->idx += 1;
+	vq_avail->idx = virtio_cpu_to_modern16(dev, avail_idx + 1);
 
 	/* Tell HV that the queue is ready */
 	virtio_queue_notify(dev, 0);
-- 
2.5.0