[PATCH 0/3] virtio-scsi updates for 3.7

[PATCH 0/3] virtio-scsi updates for 3.7

[Paolo Bonzini]

James, here is a resend of the three pending patches for
virtio-scsi, with the bugfix first.

Thanks,

Paolo

Paolo Bonzini (2):
  virtio-scsi: fix LUNs greater than 255
  virtio-scsi: support online resizing of disks

Richard W.M. Jones (1):
  virtio-scsi: initialize scatterlist structure

 drivers/scsi/virtio_scsi.c  |   39 ++++++++++++++++++++++++++++++++++++---
 include/linux/virtio_scsi.h |    2 ++
 2 files changed, 38 insertions(+), 3 deletions(-)

[PATCH 1/3] virtio-scsi: initialize scatterlist structure

[Paolo Bonzini]

From: Richard W.M. Jones <rjones@redhat.com>

The sg struct is used without being initialized, which breaks
when CONFIG_DEBUG_SG is enabled.

Cc: stable@vger.kernel.org
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 drivers/scsi/virtio_scsi.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 3e79a2f..7554d78 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -219,7 +219,7 @@ static int virtscsi_kick_event(struct virtio_scsi *vscsi,
 	struct scatterlist sg;
 	unsigned long flags;
 
-	sg_set_buf(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
+	sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
 
 	spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
 
-- 
1.7.1

[PATCH 2/3] virtio-scsi: fix LUNs greater than 255

[Paolo Bonzini]

virtio-scsi needs to report LUNs greater than 256 using the "flat"
format.  Because the Linux SCSI layer just maps the SCSI LUN to
an u32, without any parsing, these end up in the range from 16640
to 32767.  Fix max_lun to account for the possibility that logical
unit numbers are encoded with the "flat" format.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 drivers/scsi/virtio_scsi.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 7554d78..a7cf726 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -677,7 +677,11 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
 	cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
 	shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
 	shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
-	shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1;
+
+	/* LUNs > 256 are reported with format 1, so they go in the range
+	 * 16640-32767.
+	 */
+	shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
 	shost->max_id = num_targets;
 	shost->max_channel = 0;
 	shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
-- 
1.7.1

[PATCH 3/3] virtio-scsi: support online resizing of disks

[Paolo Bonzini]

Support the LUN parameter change event.  Currently, the host fires this event
when the capacity of a disk is changed from the virtual machine monitor.
The resize then appears in the kernel log like this:

  sd 0:0:0:0: [sda] 46137344 512-byte logical blocks: (23.6 GB/22.0 GIb)
  sda: detected capacity change from 22548578304 to 23622320128

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 drivers/scsi/virtio_scsi.c  |   31 ++++++++++++++++++++++++++++++-
 include/linux/virtio_scsi.h |    2 ++
 2 files changed, 32 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index a7cf726..595af1a 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -279,6 +279,31 @@ static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
 	}
 }
 
+static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
+					 struct virtio_scsi_event *event)
+{
+	struct scsi_device *sdev;
+	struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+	unsigned int target = event->lun[1];
+	unsigned int lun = (event->lun[2] << 8) | event->lun[3];
+	u8 asc = event->reason & 255;
+	u8 ascq = event->reason >> 8;
+
+	sdev = scsi_device_lookup(shost, 0, target, lun);
+	if (!sdev) {
+		pr_err("SCSI device %d 0 %d %d not found\n",
+			shost->host_no, target, lun);
+		return;
+	}
+
+	/* Handle "Parameters changed", "Mode parameters changed", and
+	   "Capacity data has changed".  */
+	if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
+		scsi_rescan_device(&sdev->sdev_gendev);
+
+	scsi_device_put(sdev);
+}
+
 static void virtscsi_handle_event(struct work_struct *work)
 {
 	struct virtio_scsi_event_node *event_node =
@@ -297,6 +322,9 @@ static void virtscsi_handle_event(struct work_struct *work)
 	case VIRTIO_SCSI_T_TRANSPORT_RESET:
 		virtscsi_handle_transport_reset(vscsi, event);
 		break;
+	case VIRTIO_SCSI_T_PARAM_CHANGE:
+		virtscsi_handle_param_change(vscsi, event);
+		break;
 	default:
 		pr_err("Unsupport virtio scsi event %x\n", event->event);
 	}
@@ -737,7 +765,8 @@ static struct virtio_device_id id_table[] = {
 };
 
 static unsigned int features[] = {
-	VIRTIO_SCSI_F_HOTPLUG
+	VIRTIO_SCSI_F_HOTPLUG,
+	VIRTIO_SCSI_F_CHANGE,
 };
 
 static struct virtio_driver virtio_scsi_driver = {
diff --git a/include/linux/virtio_scsi.h b/include/linux/virtio_scsi.h
index dc8d305..d6b4440 100644
--- a/include/linux/virtio_scsi.h
+++ b/include/linux/virtio_scsi.h
@@ -72,6 +72,7 @@ struct virtio_scsi_config {
 /* Feature Bits */
 #define VIRTIO_SCSI_F_INOUT                    0
 #define VIRTIO_SCSI_F_HOTPLUG                  1
+#define VIRTIO_SCSI_F_CHANGE                   2
 
 /* Response codes */
 #define VIRTIO_SCSI_S_OK                       0
@@ -108,6 +109,7 @@ struct virtio_scsi_config {
 #define VIRTIO_SCSI_T_NO_EVENT                 0
 #define VIRTIO_SCSI_T_TRANSPORT_RESET          1
 #define VIRTIO_SCSI_T_ASYNC_NOTIFY             2
+#define VIRTIO_SCSI_T_PARAM_CHANGE             3
 
 /* Reasons of transport reset event */
 #define VIRTIO_SCSI_EVT_RESET_HARD             0
-- 
1.7.1