Hello, Was able to reproduce it and now have a better idea of what's going on (with a temporary fix included). The issue happens when using qemu with a boot disk image exposed as a virtio-blk device. The problem is that solo5 tries to configure a virtio device that was already initialized/configured at VM early boot time. Qemu gets "confused" with the second configuration attempt, throws the "virtio: zero sized buffers are not allowed" error and gets stuck (somewhere that I couldn't determine).
Just in case, these are all the tests I tried (using qemu v3 as v5 has an issue https://github.com/Solo5/solo5/issues/463). To make things simpler I've been using the solo5 tests/test-net unikernel (c code, not mirage). You can create disk-net.img in solo5 using: tests (master) [83]> ../scripts/virtio-mkimage/solo5-virtio-mkimage.sh -f raw disk-net.img test_net/test_net.virtio These work: + boot disk image as an IDE device: qemu-3 -drive file=disk-net.img,if=ide,format=raw -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 +boot disk image as a virtio-scsi device (same as google cloud): qemu-3 -device virtio-scsi-pci,id=scsi \ -device scsi-hd,drive=hd \ -drive if=none,id=hd,file=disk-net.img,format=raw \ -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 These do NOT work: + boot disk image as a virtio-blk device: qemu-3 -drive file=disk-net.img,if=virtio,format=raw -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 The right fix would be to check in solo5 init code that the virtio device is already configured, and just skip it. For now, this temporary patch (disable virtio-blk completely) works: ============================================================================================== --- a/bindings/virtio/pci.c +++ b/bindings/virtio/pci.c @@ -54,7 +54,6 @@ static uint32_t net_devices_found; -static uint32_t blk_devices_found; #define PCI_CONF_SUBSYS_NET 1 #define PCI_CONF_SUBSYS_BLK 2 @@ -72,15 +71,6 @@ static void virtio_config(struct pci_config_info *pci) log(WARN, "Solo5: PCI:%02x:%02x: not configured\n", pci->bus, pci->dev); break; - case PCI_CONF_SUBSYS_BLK: - log(INFO, "Solo5: PCI:%02x:%02x: virtio-block device, base=0x%x, irq=%u\n", - pci->bus, pci->dev, pci->base, pci->irq); - if (!blk_devices_found++) - virtio_config_block(pci); - else - log(WARN, "Solo5: PCI:%02x:%02x: not configured\n", pci->bus, - pci->dev); - break; default: log(WARN, "Solo5: PCI:%02x:%02x: unknown virtio device (0x%x)\n", pci->bus, pci->dev, pci->subsys_id); ============================================================================================== Thanks, Ricardo On Mon, Oct 26, 2020 at 11:33 AM Ricardo Koller <ricar...@gmail.com> wrote: > Hello, > > Will reproduce it and update with some findings, hopefully by the end of > this week. > > Ricardo > > On Mon, Oct 26, 2020 at 3:48 AM Hans Ole Rafaelsen <hrafael...@gmail.com> > wrote: > >> Hi, >> >> $ qemu-system-x86_64 --version >> QEMU emulator version 2.11.1(Debian 1:2.11+dfsg-1ubuntu7.32) >> Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers >> >> -- >> Hans Ole >> >> On Mon, Oct 26, 2020 at 11:44 AM Martin Lucina <mar...@lucina.net> wrote: >> >>> (Re-sending with a current email for Ricardo) >>> >>> On Monday, 26.10.2020 at 11:37, Martin Lucina wrote: >>> > 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 >>> > >>> >>>
