[vfio-users] USB card prevents qemu finding its harddrive

[Ede Wolf]

Hello,

thanks for you answer. Unfortunately it does not seem to resolve this 
issue.

Because, if I use if=ide instead of if=virtio, I do not have this issue.


This holds true for both a 4.19 lts kernel as well as a more recent 5.4.6.

Further, when using if=virtio, no matter what address I use for the 
passed through cards, the the harddrives are always missing.
And in case I do use an already used address, qemu startup failes with 
an error, that this address is already used by [net|vga...]


Also, I do have one device, that works. If I exchange that device with 
the problematic one, using the same bus/address, the harddrives (virtio 
disk pci:00:04.0/00:05.0) are still missing.


Works (parallel card):
  -device vfio-pci,host=02:00.0,x-vga=off,bus=pci.0,addr=0x6

Does not work (changed from 0a to 08 due to changed slot):
  -device vfio-pci,host=08:00.0,x-vga=off,bus=pci.0,addr=0x6

Tried all adresses from 0x1 to 0x9. Either startup of qemu failed or no 
bootable harddrives were found.

So it does not matter wether I pass through both devices or just the 
problematic one, the harddrives are missing any way.

In addition, it makes no difference, wether I specify one or f.e. three 
drives (files). As soon as I add the problematic card, all are gone, 
when using the virtio interface.

Of course I may have made a mistake, so I am happy about suggestions or 
corrections.

Ede



Am 22.12.19 um 13:41 schrieb leesteken at pm.me:
> Hi,
> 
> Adding a device might shift the other (virtual) devices including the disk controller, or the disk controller might conflict with the default address that is used when you use -device to add it, which might remove (or not add) the disk controller.
> 
> Try adding ,addr=0x?? to the -device parameter where you select an unused address for the ??.
> You might have to select a (virtual) bus as well as part of the -device parameter.
> 
> 
> hope this helps, Arjen
> 
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On Sunday, December 22, 2019 1:14 PM, Ede Wolf <listac at nebelschwaden.de> wrote:
> 
>> So I've bought this rather expensive USB 3.0 controller, making sure it
>> was compatible to everything on this planet and having a native pcie v2
>> interface and now I am having the problem, as soon as it gets passed
>> through, qemu cannot find it's boot disk any more.
>>
>> "Boot failed. Could not read the boot disk". The boot menu only shows
>> legacy option rom or pxe.
>>
>> I have no remote idea, where the relation between those two could be. It
>> is not, that the start up of the VM itself is failing, because of a
>> misconfiguration, it's just, that after powering on of the guest, it
>> cannot find any harddrives any more and tries to pxe boot instead.
>>
>> As soon as I remove:
>> -device vfio-pci,host=0a:00.0,x-vga=off
>>
>> from the configuration, the guest starts just normal - with another card
>> still passed through. So it is not a general passthrough problem. And
>> I've had passed through two cards before.
>>
>> Needless to say, the guest image lives on a regular sata harddrive and
>> is not attached to that card in any way.
>> In addition, it is the only device in its vfio group, making it an even
>> more simple config:
>>
>> journalctl -k | grep -i iommu | grep 25
>>
>> ========================================
>>
>> Dez 22 11:50:17 kernel: pci 0000:0a:00.0: Adding to iommu group 25
>>
>> lspci -s "0a:00.0" -n -v
>>
>> =========================
>>
>> 0a:00.0 0c03: 1106:3483 (rev 01) (prog-if 30 [XHCI])
>> Subsystem: 1106:3483
>> Flags: fast devsel, IRQ 16, NUMA node 0
>> Memory at bf700000 (64-bit, non-prefetchable) [size=4K]
>> Capabilities: [80] Power Management version 3
>> Capabilities: [90] MSI: Enable- Count=1/4 Maskable- 64bit+
>> Capabilities: [c4] Express Endpoint, MSI 00
>> Capabilities: [100] Advanced Error Reporting
>> Kernel driver in use: vfio-pci
>> Kernel modules: xhci_pci
>>
>> How is it possible that this card affects the boot drive of qemu? Where
>> is the connection between "-drive file=/home/VM/guest.img" and "-device
>> vfio-pci"? And how to eventually debug this?
>>
>> Since this behaviour is related to vfio-pci, I am hoping, this is still
>> the correct list, even though this seems to affect qemu as whole. In a
>> quite obscure, magical way, one might add.
>>
>> Thanks very much for any help
>>
>> Ede
>>
>> P.S.: Preparation, even though the config should not be the issue:
>>
>> The Delock 5x USB Card (VIA)
>>
>> =============================
>>
>> ExecStart=-/usr/bin/sh -c 'echo "0000:0a:00.0" >
>> /sys/bus/pci/devices/0000:0a:00.0/driver/unbind'
>> ExecStart=/usr/bin/sh -c 'echo 1106 3483 >
>> /sys/bus/pci/drivers/vfio-pci/new_id'
>> ExecStart=/usr/bin/sh -c 'chgrp kvm /dev/vfio/25'
>> ExecStart=/usr/bin/sh -c 'chmod 0660 /dev/vfio/25'
>>
>> vfio-users mailing list
>> vfio-users at redhat.com
>> https://www.redhat.com/mailman/listinfo/vfio-users
> 
>