We should never have exposed BlockBackend names to the guest, it's a
host detail. Deprecate this behaviour. Users who need to maintain the
guest ABI can explicitly set the value with the device_id property.
Signed-off-by: Kevin Wolf <kwolf@xxxxxxxxxx>
---
hw/scsi/scsi-disk.c | 5 +++++
qemu-deprecated.texi | 22 +++++++++++++++++++++-
2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index e74e1e7c48..38f1fe2570 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -2366,6 +2366,11 @@ static void scsi_realize(SCSIDevice *dev, Error **errp)
const char *str = blk_name(s->qdev.conf.blk);
if (str && *str) {
s->device_id = g_strdup(str);
+ warn_report("Using the backend drive ID for the Device "
+ "Identification VPD page is deprecated. "
+ "Please specify the serial or device_id options "
+ "explicitly to avoid guest-visible changes in "
+ "future QEMU versions.");
}
}
}
diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
index 219206a836..a426d8245d 100644
--- a/qemu-deprecated.texi
+++ b/qemu-deprecated.texi
@@ -146,7 +146,7 @@ This machine type uses an unmaintained firmware, broken in lots of ways,
and unable to start post-2004 operating systems. 40p machine type should be
used instead.
-@section Device options
+@section Devices
@subsection Block device options
@@ -170,6 +170,26 @@ The above, converted to the current supported format:
@code{json:@{"file.driver":"rbd", "file.pool":"rbd", "file.image":"name"@}}
+@subsection scsi-disk device identification (since 4.0.0)
+
+The Device Identification VPD page of ``scsi-disk'' devices contains a vendor
+specific designator that can be explicitly specified using the ``device_id''
+property since 4.0.0.
+
+If ``device_id'' is not given, the implementation falls back to reusing any
+specified serial number for this field. If the serial number is not given
+either and ``drive=X'' was used where ``X'' is a drive ID, this drive ID is
+given to the guest instead. This is backend information that should not
+to be exposed to guests.
+
+Therefore, this behaviour is deprecated and future versions will change the
+guest-visible behaviour (e.g. by leaving out the vendor specific designator)
+for the case that neither ``device_id'' nor a serial number are given, but a
+drive ID is used to create the device.
+
+If you need the guest-visible information to stay unchanged, add an explicit
+``device_id'' option to your QEMU invocation.
+
@subsection vio-spapr-device device options
@subsubsection "irq": "" (since 3.0.0)
--
2.20.1
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