On Thu, Jun 20, 2024 at 04:00:05PM +0200, Igor Mammedov wrote:
Regardless of which way is chosen some users will suffer one way or another. My vote would be to keep current behavior so 'modern' guests would work without issues.
The Linux kernel policy is "no regressions", I cannot say it better than Linus himself (if you'll excuse the shouting):
https://lkml.org/lkml/2018/8/3/621
This is exactly what happened here - we updated seabios and things stopped working. It's unfortunate that the long tail of legacy exists, and we all wish it didn't, but it does.
On Thu, Jun 20, 2024 at 04:09:24PM +0200, Igor Mammedov wrote:
On Wed, 19 Jun 2024 11:21:14 +0100 John Levon john.levon@nutanix.com wrote:
Older 32-bit Linux VMs (including Ubuntu 16.10) have issues with the 64-bit pci io window, failing during boot with errors like:
virtio_balloon virtio2: virtio: device uses modern interface but does not have VIRTIO_F_VERSION_19734-565debf7b362 virtio_net virtio0: virtio: device uses modern interface but does not have VIRTIO_F_VERSION_1 Virtio_scsi virtio1: virtio: device uses modern interface but does not have VIRTIO_F_VERSION_1
above aren't exactly indicate 64-bit MMIO window as culprit
Can you provide more data on what exactly goes wrong and where?
Sorry, no idea, and I don't think it's a useful exercise to debug old Linux kernels.
Does adding 'realloc' option to guest kernel CLI help?
I'll try this and get back to you.
This isn't a practical solution in general though IMO, it's not reasonable to ask our downstream customers (and their downstream customers and so on) to figure out how to do this across what could well be thousands of VMs minimum.
regards john