On 01/09/2013 01:02 PM, Daniel P. Berrange wrote:
On Wed, Jan 09, 2013 at 12:36:52PM -0500, Laine Stump wrote:
On Wed, Jan 09, 2013 at 08:14:07AM -0700, Eric Blake wrote:
On 01/09/2013 01:39 AM, Amos Kong wrote:
Current seabios will try to boot from selected devices first, if they are all failed, seabios will also try to boot from un-selected devices.
We need to make it configurable. I already posted a seabios patch to add a new device type to halt booting. Qemu can add "HALT" at the end of bootindex string, then seabios will halt booting after trying to boot from selected devices.
This option only effects when boot priority is changed by bootindex options, the old style(-boot order=..) will still try to boot from un-selected devices.
v2: add HALT entry in get_boot_devices_list() define boot_strict to bool
Signed-off-by: Amos Kong <akong@redhat.com> --- Libvirt will need to expose an attribute that lets the user control whether to use this new option; how do we probe via QMP whether the new -boot strict=on command-line option is available? Old style to adjust boot priority by order parameter: -boot order=n,strict=on (BAD, unselected devices will be tried)
New style to adjust boot priority by bootindex: -device virtio-net-pci,...,bootindex=1 -boot strict=on (OK)
We only want strict option to support new style.
(those two styles are implemented in two different way insider seabios, the latest simple patch only changed the bootindex way) Just a note about this: as far as I can tell virt-manager currently only uses the "old style" of specifying boot order; it needs to be enhanced to recognize the presence of bootindex=n ordering, and behave accordingly. Looking from the outside, that looks to be not completely
On 01/09/2013 10:52 AM, Amos Kong wrote: trivial, as the old style of ordering only allows specifying "hard disk" as a single line in the priority order, but the new style has each disk specified separately. Not only that, but *which* of the disks is tried first under the old order may change depending on whether or not a bootmenu is requested (in one case it picks unit=0 on the controller, in the other case, it orders the disks alphabetically by target dev name) Hmm, well libvirt should be using bootindex=n on the QEMU command line regardless of what applications put in the XML. ie if the application uses the old style XML, libvirt should translate that into bootindex=n for them.
Good point. WHerever it's changed though, it will be a bit tricky to preserve current behavior, due to the idiosyncrasies I noted above.