git: f056e84e5b46 - main - virtio-scsi: handle device capacity change event

The branch main has been updated by ray:

URL: https://cgit.FreeBSD.org/src/commit/?id=f056e84e5b46acd33c5e872f384683718313bad8

commit f056e84e5b46acd33c5e872f384683718313bad8
Author:     Aleksandr Rybalko <ray@FreeBSD.org>
AuthorDate: 2026-05-26 14:49:21 +0000
Commit:     Aleksandr Rybalko <ray@FreeBSD.org>
CommitDate: 2026-06-11 12:30:04 +0000

    virtio-scsi: handle device capacity change event
    
    This feature is utilized when updating storage capacity in capable hypervisors such as QEMU.
    
    Reviewed by:    imp
    Approved by:    imp(mentor)
    Obtained from:  Fudo Security
    MFC after:      2 weeks
    Sponsored by:   Fudo Security
    Differential Revision:  https://reviews.freebsd.org/D57247
---
 sys/dev/virtio/scsi/virtio_scsi.c    | 24 ++++++++++++++++++++++++
 sys/dev/virtio/scsi/virtio_scsi.h    |  9 +++++++++
 sys/dev/virtio/scsi/virtio_scsivar.h |  1 +
 3 files changed, 34 insertions(+)

diff --git a/sys/dev/virtio/scsi/virtio_scsi.c b/sys/dev/virtio/scsi/virtio_scsi.c
index 857da56ba426..a61c92485ccc 100644
--- a/sys/dev/virtio/scsi/virtio_scsi.c
+++ b/sys/dev/virtio/scsi/virtio_scsi.c
@@ -1786,6 +1786,27 @@ vtscsi_transport_reset_event(struct vtscsi_softc *sc,
 	}
 }
 
+static void
+vtscsi_param_change_event(struct vtscsi_softc *sc,
+    struct virtio_scsi_event *event)
+{
+	target_id_t target_id;
+	lun_id_t lun_id;
+
+	vtscsi_get_request_lun(event->lun, &target_id, &lun_id);
+
+	if (VIRTIO_SCSI_ASC(event->reason) == VIRTIO_SCSI_CAPACITY_CHNG_ASC &&
+	    VIRTIO_SCSI_ASCQ(event->reason) == VIRTIO_SCSI_CAPACITY_CHNG_ASCQ) {
+		/* Disk capacity has changed. */
+		vtscsi_announce(sc, AC_INQ_CHANGED, target_id, lun_id);
+	} else {
+		device_printf(sc->vtscsi_dev,
+		    "unhandled PARAM_CHANGE event. ASC: %02x, ASCQ: %02x\n",
+		    VIRTIO_SCSI_ASC(event->reason),
+		    VIRTIO_SCSI_ASCQ(event->reason));
+	}
+}
+
 static void
 vtscsi_handle_event(struct vtscsi_softc *sc, struct virtio_scsi_event *event)
 {
@@ -1796,6 +1817,9 @@ vtscsi_handle_event(struct vtscsi_softc *sc, struct virtio_scsi_event *event)
 		case VIRTIO_SCSI_T_TRANSPORT_RESET:
 			vtscsi_transport_reset_event(sc, event);
 			break;
+		case VIRTIO_SCSI_T_PARAM_CHANGE:
+			vtscsi_param_change_event(sc, event);
+			break;
 		default:
 			device_printf(sc->vtscsi_dev,
 			    "unhandled event: %d\n", event->event);
diff --git a/sys/dev/virtio/scsi/virtio_scsi.h b/sys/dev/virtio/scsi/virtio_scsi.h
index 02e13c6f81b7..66c72304f3f1 100644
--- a/sys/dev/virtio/scsi/virtio_scsi.h
+++ b/sys/dev/virtio/scsi/virtio_scsi.h
@@ -162,6 +162,15 @@ struct virtio_scsi_config {
 #define VIRTIO_SCSI_T_ASYNC_NOTIFY             2
 #define VIRTIO_SCSI_T_PARAM_CHANGE             3
 
+/*
+ * SCSI ASC/ASCQ Sense Codes
+ * https://www.t10.org/lists/asc-num.txt
+ */
+#define VIRTIO_SCSI_ASC(x)			((x) & 0xff)
+#define VIRTIO_SCSI_ASCQ(x)			(((x) >> 8) & 0xff)
+#define VIRTIO_SCSI_CAPACITY_CHNG_ASC		0x2a
+#define VIRTIO_SCSI_CAPACITY_CHNG_ASCQ		0x09
+
 /* Reasons of transport reset event */
 #define VIRTIO_SCSI_EVT_RESET_HARD             0
 #define VIRTIO_SCSI_EVT_RESET_RESCAN           1
diff --git a/sys/dev/virtio/scsi/virtio_scsivar.h b/sys/dev/virtio/scsi/virtio_scsivar.h
index 85d2990d8bf4..b5f3c59727cc 100644
--- a/sys/dev/virtio/scsi/virtio_scsivar.h
+++ b/sys/dev/virtio/scsi/virtio_scsivar.h
@@ -139,6 +139,7 @@ struct vtscsi_request {
 /* Features desired/implemented by this driver. */
 #define VTSCSI_FEATURES \
     (VIRTIO_SCSI_F_HOTPLUG		| \
+     VIRTIO_SCSI_F_CHANGE		| \
      VIRTIO_RING_F_INDIRECT_DESC)
 
 #define VTSCSI_MTX(_sc)			&(_sc)->vtscsi_mtx