Re: [libvirt] [PATCH 3/3] scsi-disk: Deprecate device_id fallback to BlockBackend name
On Fri, Jan 25, 2019 at 06:46:53PM +0100, Kevin Wolf wrote:
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.
I don't think we've deprecated things in the past which would cause
a guest ABI change when finally deleted.
Shouldn't we be instead setting using machine type versioning here,
so that existing machine types keep using the blk_name() fallback
forever, while QEMU 4.0+ machine types avoid blk_name() fallback
immediately.
Signed-off-by: Kevin Wolf <kwolf(a)redhat.com>
---
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.");
}
}
}
Regards,
Daniel
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