Re: [Xen-devel] Xen-unstable: pci-passthrough regression bisected to: x86/smp: use APIC ALLBUT destination shorthand when possible

[Sander Eikelenboom <linux@xxxxxxxxxxxxxx>]

On 03/02/2020 13:23, Roger Pau Monné wrote:
> On Mon, Feb 03, 2020 at 09:33:51AM +0100, Sander Eikelenboom wrote:
>> Hi Roger,
>>
>> Last week I encountered an issue with the PCI-passthrough of a USB 
>> controller. 
>> In the guest I get:
>>     [ 1143.313756] xhci_hcd 0000:00:05.0: xHCI host not responding to stop 
>> endpoint command.
>>     [ 1143.334825] xhci_hcd 0000:00:05.0: xHCI host controller not 
>> responding, assume dead
>>     [ 1143.347364] xhci_hcd 0000:00:05.0: HC died; cleaning up
>>     [ 1143.356407] usb 1-2: USB disconnect, device number 2
>>
>> Bisection turned up as the culprit: 
>>    commit 5500d265a2a8fa63d60c08beb549de8ec82ff7a5
>>    x86/smp: use APIC ALLBUT destination shorthand when possible
> 
> Sorry to hear that, let see if we can figure out what's wrong.

No problem, that is why I test stuff :)

>> I verified by reverting that commit and now it works fine again.
> 
> Does the same controller work fine when used in dom0?

Will test that, but as all other pci devices in dom0 work fine,
I assume this controller would also work fine in dom0 (as it has also
worked fine for ages with PCI-passthrough to that guest and still works
fine when reverting the referenced commit).

I don't know if your change can somehow have a side effect
on latency around the processing of pci-passthrough ?
(since the driver concluding that a device is non-responsive, will
probably be at least somewhat latency sensitive).

--
Sander

> Thanks, Roger.
> 


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel