Am 28.01.2019 um 09:50 hat Peter Krempa geschrieben:
On Fri, Jan 25, 2019 at 18:46:52 +0100, Kevin Wolf wrote:
The new device_id property specifies which value to use for the vendor specific designator in the Device Identification VPD page.
In particular, this is necessary for libvirt to maintain guest ABI compatibility when no serial number is given and a VM is switched from -drive (where the BlockBackend name is used) to -blockdev (where the vendor specific designator is left out by default).
Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- hw/scsi/scsi-disk.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)
[...]
@@ -2904,7 +2910,9 @@ static const TypeInfo scsi_disk_base_info = { DEFINE_PROP_STRING("ver", SCSIDiskState, version), \ DEFINE_PROP_STRING("serial", SCSIDiskState, serial), \ DEFINE_PROP_STRING("vendor", SCSIDiskState, vendor), \ - DEFINE_PROP_STRING("product", SCSIDiskState, product) + DEFINE_PROP_STRING("product", SCSIDiskState, product), \ + DEFINE_PROP_STRING("device_id", SCSIDiskState, device_id)
This adds the property only to 'scsi-disk', whereas libvirt will use 'scsi-cd' or 'scsi-hd' depending on the media type if the 'scsi-cd' device is detected.
I'm adding this to the macro DEFINE_SCSI_DISK_PROPERTIES(), which is used for scsi-hd, scsi-cd and scsi-disk. It is not added to scsi-block, but there we pass through the VPD page of the real disk, so this looks correct to me.
The following logic decides:
https://libvirt.org/git/?p=libvirt.git;a=blob;f=src/qemu/qemu_command.c;h=3e...
This brings multiple questions:
1) Is this necssary also for scsi-cd/scsi-hd and if yes, the property does not seem to be present for those
Yes, but the property is added there.
2) Is actually using 'scsi-cd'/'scsi-hd' the better option than 'scsi-disk'?
Yes, scsi-disk is a legacy device. Maybe we should formally deprecate it.
3) Since upstream libvirt supports qemu-1.5 and newer and 'scsi-cd' is already supported there, can we assume that all newer versions support it? (Basically the question is whether it can be compiled out by upstream means).
I think so. Kevin