[pve-devel] USB Host passthrough high cpu / interupt usage

[Alexandre DERUMIER]

>>At least i could hack QemuServer.pm and try it before doing any real patch. 

Yes!


>>Is it just replacing uhci with xhci all the time? 
mmm,I'm not sure, because xhci don't support usb1 hub. (currently usb2 controller avec 1 usb1 controller plugged into it)

doc is here:
http://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb2.txt;hb=HEAD


maybe simply add a new controller:
 -device nec-usb-xhci,id=xhci....


then change bus=xhci.0 in usb devices


>>Does the machine type (pc vs q35) makes any difference? 
Don't known for usb. I known that q35 should improve pci express support in guest.




----- Mail original ----- 

De: "Stefan Priebe - Profihost AG" <s.priebe at profihost.ag> 
À: "Alexandre DERUMIER" <aderumier at odiso.com> 
Cc: pve-devel at pve.proxmox.com 
Envoyé: Mercredi 26 Mars 2014 09:57:56 
Objet: Re: [pve-devel] USB Host passthrough high cpu / interupt usage 


Am 26.03.2014 08:47, schrieb Alexandre DERUMIER: 
> Hi Stefan, 
> 
> Do you see interrupts only when data transfer occur ? 

Not really sure how to check as data transfer occours all the time. 


> I known that qemu usb3 implementation use less interrupts, 
> maybe could we try to implemented it in proxmox. (xhci controller) 
> (should not be a big task) 

At least i could hack QemuServer.pm and try it before doing any real patch. 

Is it just replacing uhci with xhci all the time? Does the machine type 
(pc vs q35) makes any difference? 

Stefan 


> ----- Mail original ----- 
> 
> De: "Stefan Priebe" <s.priebe at profihost.ag> 
> À: pve-devel at pve.proxmox.com 
> Envoyé: Mardi 25 Mars 2014 23:07:48 
> Objet: [pve-devel] USB Host passthrough high cpu / interupt usage 
> 
> Hi, 
> 
> i'm trying to pass through 5 usb devices from the host to the guest. 
> What i'm wondering is the very high interupt and cpu usage of the guest. 
> 
> These usb devices i'm passing are just tty / serial ones - so the data 
> transfer is VERY low. 
> 
> Does anybody habe an idea? Latency for USB data is also very high around 
> 130ms. 
> 
> Stefan 
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