USB installs using VT and block devices

[pevogam]

Hi all, is there a well established way to perform USB installs using Avocado VT? I had a working version using the legacy -drive option (but not confirmed to be best way to do it) and have modified it in the following way to make it work for block devices:

-                    # TODO: this variant has many hiccups while also being too critical
-                    # so retry until a fix is available on the qemu upstream side
-                    stop_status = pass
-                    max_tries = 10
-                    max_concurrent_tries = 1
                     # TODO: adding to suffixed parameters at this stage doesn't work
                     #images += " flash"
                     images_vm3 = image1 flash
                     image_name_flash = ${cdrom_cd1}
-                    image_boot_flash = yes
-                    image_format_flash =
+                    # TODO: the bootindex expectation to eventually get to the USB fails for some reason
+                    bootindex_flash = 0
+                    bootindex_image1 = 1
+                    # NOTE: empty value is not treated the same way as none for the image format
+                    del image_format_vm3
+                    image_format_image1 = qcow2
                     image_readonly_flash = yes
+                    image_raw_device_flash = yes
                     # usb type configuration
                     drive_format_flash = usb2
                     usbs_vm3 = usb1 default-ehci
                     usb_type_default-ehci = usb-ehci
                     usb_controller_default-ehci = ehci
                     # add removable flag to the flash drive
                     removable_flash = yes
                     # we need to see the boot menu in order to be able to skip the usb on reboot
                     boot_menu_vm3 = on
                     # disable install CDs meant for the general OS version
                     cdroms_vm3 =

This resulted in the following changes on the Qemu command line from

[stdlog]     -drive id=drive_flash,if=none,readonly=on,cache=none,file=/mnt/local/isos/business-server-6-12-1.iso \                                                                                                                        
[stdlog]     -device usb-storage,removable=on,id=flash,drive=drive_flash,bootindex=0,bus=default-ehci.0,port=1 \

to

[stdlog]     -blockdev node-name=file_flash,driver=file,auto-read-only=on,filename=/mnt/local/isos/business-server-6-12-1.iso,cache.direct=on,cache.no-flush=off \                                                                         
[stdlog]     -blockdev node-name=drive_flash,driver=raw,read-only=on,cache.direct=on,cache.no-flush=off,file=file_flash \                                                                                                                  
[stdlog]     -device usb-storage,removable=on,id=flash,drive=drive_flash,bootindex=0,write-cache=on,bus=default-ehci.0,port=1 \    

where unfortunately I had to modify the bootindex of the flash drive to 0 despite the fact that it was supposed to be discovered by Qemu if the bootindex 0 image is not bootable.

I have seen in some part of the avocado VT codebase something like this that suggests we can just change the drive format of the CD:

    - usb2:
        drive_format=usb2
        cd_format=usb2

Is this really the case?

@luckyh @YongxueHong Do you have any suggestions? Thank in advance for your time!

[YongxueHong]

Hi @pevogam
Sorry for replying later. If I understood it, you mean that we can not create the related USB command without the bootindex right? Or we can not discover this USB block device with QMP and HMP?
Could you provide more details?
Thanks.

[pevogam]

What I mean is that we need the extra lines

                    # TODO: the bootindex expectation to eventually get to the USB fails for some reason
                    bootindex_flash = 0
                    bootindex_image1 = 1

in order to be able to properly boot from the added "flash" image even if the previous "image1" is blank, not bootable, and has no OS installed in it. I had to manually change the bootindex of the block devices to make this work and it would still not work if we have to reboot in the middle of the test because the added "flash" remains bootable and has hardcoded bootindex of 0.

Also the question is a bit more general than this - is this a good way to perform a USB installation test or is there a more established/standard one in Avocado VT?