On Tue, May 22, 2018 at 09:35:55AM +0200, Gerd Hoffmann wrote: > Hi, > > > You must /sometimes/ supply the correct machine type. > > > > It is quite dependent on the guest OS you have installed, and even > > just how the guest OS is configured. In general Linux is very > > flexible and can adapt to a wide range of hardware, automatically > > detecting things as needed. It is possible for a sysadmin to build > > a Linux image in a way that would only work with I440FX, but I > > don't think it would be common to see that. > > I think it would be pretty hard to actually build such an image. > > The more critical thing for linux guests is the storage driver which > must be included into the initrd so the image can mount the root > filesystem. And the firmware, bios vs. uefi is more critical than > pc vs. q35.
I think we can start by finding a location to embed a string in a qcow image, add ability for qemu-img to set and get this string. We can discuss how it's formatted separately. > > That said I'm not really convinced that using the qcow2 headers is > > a good plan. We have many disk image formats in common use, qcow2 > > is just one. Even if the user provides the image in qcow2 format, > > that doesn't mean that mgmt apps actually store the qcow2 file. > > > I tend to think we'd be better looking at what we can do in the context > > of an existing standard like OVF rather than inventing something that > > only works with qcow2. I think it would need to be more expressive than > > just a single list of key,value pairs for each item. > > Embed OVF metadata in the qcow2 image? > > cheers, > Gerd What would be helpful is if we could tell the user who wonders how to run an image "hey you probably want flags X,Y and Z". I can see how we could have an option to either stick a bit of XML there, or just some QEMU flags. -- MST