[PATCH v3] virtio_blk: Add support for lifetime feature

Enrico Granata
2021-12-07T17:55:37Z

From: Enrico Granata <egranata@google.com>

The VirtIO TC has adopted a new feature in virtio-blk enabling
discovery of lifetime information.

This commit adds support for the VIRTIO_BLK_T_LIFETIME command
to the virtio_blk driver, and adds new attributes to the
sysfs entry for virtio_blk:
* pre_eol_info
* life_time_a
* life_time_b

which are defined in the VirtIO specification.

Signed-off-by: Enrico Granata <egranata@google.com>
---
Changes in v3:
- Split life_time attribute in two
- Made VirtIO specification independent of eMMC
- Adopted newer APIs to mirror surrounding code

drivers/block/virtio_blk.c | 106 ++++++++++++++++++++++++++++++--
include/uapi/linux/virtio_blk.h | 11 ++++
2 files changed, 113 insertions(+), 4 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 6ae38776e30e..c50f5d9a173b 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -213,7 +213,7 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
struct virtblk_req *vbr)
{
bool unmap = false;
- u32 type;
+ u32 type = 0;

vbr->out_hdr.sector = 0;

@@ -239,14 +239,14 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
unmap = !(req->cmd_flags & REQ_NOUNMAP);
break;
case REQ_OP_DRV_IN:
- type = VIRTIO_BLK_T_GET_ID;
- break;
+ break; /* type already set for custom requests */
default:
WARN_ON_ONCE(1);
return BLK_STS_IOERR;
}

- vbr->out_hdr.type = cpu_to_virtio32(vdev, type);
+ if (req_op(req) != REQ_OP_DRV_IN)
+ vbr->out_hdr.type = cpu_to_virtio32(vdev, type);
vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));

if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
@@ -374,11 +374,14 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
struct virtio_blk *vblk = disk->private_data;
struct request_queue *q = vblk->disk->queue;
struct request *req;
+ struct virtblk_req *vbr;
int err;

req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
if (IS_ERR(req))
return PTR_ERR(req);
+ vbr = blk_mq_rq_to_pdu(req);
+ vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID);

err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
if (err)
@@ -391,6 +394,35 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
return err;
}

+static int virtblk_get_lifetime(struct gendisk *disk, struct virtio_blk_lifetime *lifetime)
+{
+ struct virtio_blk *vblk = disk->private_data;
+ struct request_queue *q = vblk->disk->queue;
+ struct request *req;
+ struct virtblk_req *vbr;
+ int err;
+
+ if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_LIFETIME))
+ return -EOPNOTSUPP;
+
+ req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+ vbr = blk_mq_rq_to_pdu(req);
+ vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_LIFETIME);
+
+ err = blk_rq_map_kern(q, req, lifetime, sizeof(*lifetime), GFP_KERNEL);
+ if (err)
+ goto out;
+
+ blk_execute_rq(vblk->disk, req, false);
+ err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
+out:
+ blk_mq_free_request(req);
+ return err;
+}
+
+
static void virtblk_get(struct virtio_blk *vblk)
{
refcount_inc(&vblk->refs);
@@ -499,6 +531,68 @@ static ssize_t serial_show(struct device *dev,

static DEVICE_ATTR_RO(serial);

+static ssize_t pre_eol_info_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ struct virtio_blk_lifetime lft;
+ int err;
+
+ /* sysfs gives us a PAGE_SIZE buffer */
+ BUILD_BUG_ON(sizeof(lft) >= PAGE_SIZE);
+
+ err = virtblk_get_lifetime(disk, &lft);
+ if (err)
+ return 0;
+
+ return sprintf(buf, "0x%02x\n", le16_to_cpu(lft.pre_eol_info));
+}
+
+static DEVICE_ATTR_RO(pre_eol_info);
+
+static ssize_t life_time_a_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ struct virtio_blk_lifetime lft;
+ int err;
+
+ /* sysfs gives us a PAGE_SIZE buffer */
+ BUILD_BUG_ON(sizeof(lft) >= PAGE_SIZE);
+
+ err = virtblk_get_lifetime(disk, &lft);
+ if (err)
+ return 0;
+
+ return sprintf(buf, "0x%02x\n",
+ le16_to_cpu(lft.device_life_time_est_typ_a));
+}
+
+static DEVICE_ATTR_RO(life_time_a);
+
+static ssize_t life_time_b_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ struct virtio_blk_lifetime lft;
+ int err;
+
+ /* sysfs gives us a PAGE_SIZE buffer */
+ BUILD_BUG_ON(sizeof(lft) >= PAGE_SIZE);
+
+ err = virtblk_get_lifetime(disk, &lft);
+ if (err)
+ return 0;
+
+ return sprintf(buf, "0x%02x\n",
+ le16_to_cpu(lft.device_life_time_est_typ_b));
+}
+
+static DEVICE_ATTR_RO(life_time_b);
+
/* The queue's logical block size must be set before calling this */
static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
{
@@ -702,6 +796,9 @@ static DEVICE_ATTR_RW(cache_type);
static struct attribute *virtblk_attrs[] = {
&dev_attr_serial.attr,
&dev_attr_cache_type.attr,
+ &dev_attr_pre_eol_info.attr,
+ &dev_attr_life_time_a.attr,
+ &dev_attr_life_time_b.attr,
NULL,
};

@@ -1042,6 +1139,7 @@ static unsigned int features[] = {
VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
+ VIRTIO_BLK_F_LIFETIME,
};

static struct virtio_driver virtio_blk = {
diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h
index d888f013d9ff..7ca0b3aac570 100644
--- a/include/uapi/linux/virtio_blk.h
+++ b/include/uapi/linux/virtio_blk.h
@@ -40,6 +40,7 @@
#define VIRTIO_BLK_F_MQ 12 /* support more than one vq */
#define VIRTIO_BLK_F_DISCARD 13 /* DISCARD is supported */
#define VIRTIO_BLK_F_WRITE_ZEROES 14 /* WRITE ZEROES is supported */
+#define VIRTIO_BLK_F_LIFETIME 15 /* LIFETIME is supported */

/* Legacy feature bits */
#ifndef VIRTIO_BLK_NO_LEGACY
@@ -149,6 +150,9 @@ struct virtio_blk_config {
/* Get device ID command */
#define VIRTIO_BLK_T_GET_ID 8

+/* Get device lifetime command */
+#define VIRTIO_BLK_T_GET_LIFETIME 10
+
/* Discard command */
#define VIRTIO_BLK_T_DISCARD 11

@@ -160,6 +164,13 @@ struct virtio_blk_config {
#define VIRTIO_BLK_T_BARRIER 0x80000000
#endif /* !VIRTIO_BLK_NO_LEGACY */

+/* Lifetime information for virtio_blk device */
+struct virtio_blk_lifetime {
+ __le16 pre_eol_info;
+ __le16 device_life_time_est_typ_a;
+ __le16 device_life_time_est_typ_b;
+};
+
/*
* This comes first in the read scatter-gather list.
* For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated,
--
2.34.1.400.ga245620fadb-goog