Re: [Qemu-devel] virtio block device is not working

[joserz@linux.vnet.ibm.com]

On Tue, Jan 23, 2018 at 01:05:28AM -0200, joserz@linux.vnet.ibm.com wrote:
> Hello people!
> 
> I'm not able to boot any guest that sets a virtio block device like:
> (branch master)
> 
> [PPC64]
> qemu-system-ppc64 -cpu POWER8 -nographic -vga none -m 4G -M pseries,accel=kvm,kvm-type=PR -drive file=disk.qcow2,if=virtio

my bad, actually the command line is:

qemu-system-ppc64 -cpu POWER8 -nographic -vga none -m 4G -M pseries,accel=kvm -netdev type=user,id=net0 -device virtio-net-pci,netdev=net0 -drive file=../disk.qcow2,if=virtio

and the problem seem to be in virtio-net-pci, not in the block device


> QEMU Starting
>  Build Date = Dec 18 2017 13:08:00
>  FW Version = git-fa981320a1e0968d
>  Press "s" to enter Open Firmware.
> 
> Populating /vdevice methods
> Populating /vdevice/vty@71000000
> Populating /vdevice/nvram@71000001
> Populating /vdevice/v-scsi@71000002
>        SCSI: Looking for devices
>           8200000000000000 CD-ROM   : "QEMU     QEMU CD-ROM      2.5+"
> Populating /pci@800000020000000
>                      00 0000 (D) : 1af4 1000    virtio [ net ]
> Aborted
> 
> [x86]
> 
> qemu-system-x86_64 -m 4G -enable-kvm -drive file=util.qcow2,if=virtio
> Running QEMU with GTK 2.x is deprecated, and will be removed
> in a future release. Please switch to GTK 3.x instead
> [1]    5282 abort
> 
> [Cause]
> 
> The commit 4fe6d78b2e introduces the
> 
> ...
> kvm_mem_ioeventfd_del(...) {
>     ...
>     r = kvm_set_ioeventfd_mmio(fd, ...
>     if (r < 0) {
>         abort();
>     }
> 
> +    if (e->cleanup) {
> +        e->cleanup(e);
> +    }
> }
> 
> For some reason, not yet clear to me, cleanup() calls the same
> kvm_mem_ioeventfd_del again and again until kvm_set_ioeventfd_mmio
> returns < 0 and abort().
> 
> I was going to send a patch to revert that 'if ()' but I think it could
> cause a regression. What do you guys think?
> 
> Thanks,
> 
> Jose Ricardo Ziviani
> 
>