Re: MirageOS on OpenStack problem

[Martin Lucina <martin@xxxxxxxxxx>]

Hi,

On Sunday, 25.10.2020 at 13:37, Hans Ole Rafaelsen wrote:
> Hi,
> 
> I have been investigating some more, and I seem to be a 'virtio-block
> device' problem. On the OpenStack cloud this device is reported when Solo5
> boots, but not on my local installation.
> 
> I changed from IDE (default) to virtio as a drive on my local installation,
> and that gives the same behaviour as on the cloud. So the behaviour can be
> shown with these two different examples.
> 
> Using a IDE drive for the image:
> $ qemu-system-x86_64 -cpu Westmere -m 128 -nodefaults -no-acpi -display
> none -serial stdio -device virtio-net,netdev=n0 -netdev
> tap,id=n0,ifname=tap100,script=no,downscript=no -device isa-debug-exit
> -device lsi,id=scsi0,bus=pci.0,addr=0x9 \
> -drive
> file=/home/hans/src/5g/mirage/repository.qcow2,format=qcow2,if=none,id=drive-ide0-0-0
> -device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1
> 
> SYSLINUX 6.03 20171017 Copyright (C) 1994-2014 H. Peter Anvin et al
> Loading unikernel.bin... ok
>             |      ___|
>   __|  _ \  |  _ \ __ \
> \__ \ (   | | (   |  ) |
> ____/\___/ _|\___/____/
> Solo5: Bindings version v0.6.7
> Solo5: Memory map: 128 MB addressable:
> Solo5:   reserved @ (0x0 - 0xfffff)
> Solo5:       text @ (0x100000 - 0x481fff)
> Solo5:     rodata @ (0x482000 - 0x51dfff)
> Solo5:       data @ (0x51e000 - 0x74efff)
> Solo5:       heap >= 0x74f000 < stack < 0x8000000
> Solo5: Clock source: TSC, frequency estimate is 2808856460 Hz
> Solo5: PCI:00:02: virtio-net device, base=0xc100, irq=10
> Solo5: PCI:00:02: configured, mac=52:54:00:12:34:56, features=0x79bfffe7
> Solo5: Application acquired 'service' as network device
> 2020-10-25 12:16:34 -00:00: INF [netif] Plugging into service with mac
> 52:54:00:12:34:56 mtu 1500
> 2020-10-25 12:16:34 -00:00: INF [ethernet] Connected Ethernet interface
> 52:54:00:12:34:56
> 
> Using virtio drive for the image:
> $ qemu-system-x86_64 -cpu Westmere -m 128 -nodefaults -no-acpi -display
> none -serial stdio -device virtio-net,netdev=n0 -netdev
> tap,id=n0,ifname=tap100,script=no,downscript=no -device isa-debug-exit \
> -drive
> file=/home/hans/src/hermod-5g/mirage/repository.qcow2,format=qcow2,if=none,id=drive-virtio-disk0
> -device
> virtio-blk-pci,scsi=off,bus=pci.0,addr=0xa,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
> 
> 
> SYSLINUX 6.03 20171017 Copyright (C) 1994-2014 H. Peter Anvin et al
> Loading unikernel.bin... ok
>             |      ___|
>   __|  _ \  |  _ \ __ \
> \__ \ (   | | (   |  ) |
> ____/\___/ _|\___/____/
> Solo5: Bindings version v0.6.7
> Solo5: Memory map: 127 MB addressable:
> Solo5:   reserved @ (0x0 - 0xfffff)
> Solo5:       text @ (0x100000 - 0x481fff)
> Solo5:     rodata @ (0x482000 - 0x51dfff)
> Solo5:       data @ (0x51e000 - 0x74efff)
> Solo5:       heap >= 0x74f000 < stack < 0x7ffe000
> Solo5: Clock source: TSC, frequency estimate is 2809165540 Hz
> Solo5: PCI:00:02: virtio-net device, base=0xc040, irq=10
> Solo5: PCI:00:02: configured, mac=52:54:00:12:34:56, features=0x79bfffe7
> Solo5: PCI:00:0a: virtio-block device, base=0xc000, irq=10
> Solo5: PCI:00:0a: configured, capacity=2097152 sectors, features=0x79000e54
> qemu-system-x86_64: virtio: zero sized buffers are not allowed

Looks like some bug with recent QEMU and the Solo5 virtio-block
implementation.

What QEMU version is that?

As I wrote, the virtio target does not get much testing :-(

> Is the problem that I need to set up handlers etc. to handle a virtio block
> device in the MirageOS application? I can't find anything about this in the
> documentation. Or might it be a bug in Solo5/MirageOS?

No, it's a bug.

Cc:ing Ricardo who may be able to look into it.

Martin