Re: [Qemu-devel] [PATCH] xen_pt: fix failure of attaching & detaching a PCI device to VM repeatedly

[Chang, JianzhongX]

Bug url : http://bugzilla-archived.xenproject.org/bugzilla/show_bug.cgi?id=1905
Above url descripts the bug which i fix in more detail.
Add pci = [ '$VF_BDF', '$VF_BDF', '$VF_BDF'], $VF_BDFs are different.
pci = [ '$VF_BDF1', '$VF_BDF2', '$VF_BDF3'] is a more accurate description.

-----Original Message-----
From: Li, Liang Z 
Sent: Sunday, December 06, 2015 11:05 PM
To: Stefano Stabellini; Chang, JianzhongX
Cc: address@hidden; address@hidden; address@hidden; Lan, Tianyu; address@hidden
Subject: RE: [PATCH] xen_pt: fix failure of attaching & detaching a PCI device 
to VM repeatedly

> > Add pci = [ '$VF_BDF', '$VF_BDF', '$VF_BDF'] in
> 
> This is a bit confusing: it is not actually correct to assign the same 
> device, even an SR_IOV VF, multiple times, so these must be all different. 
> More like:
> 
> pci = [ '$VF_BDF1', '$VF_BDF2', '$VF_BDF3']
> 
> 
> > hvm guest configuration file. After the guest boot up, detach the 
> > VFs in sequence by "xl pci-detach $DOMID $VF_BDF", reattach the VFs 
> > by "xl pci-attach $VF_BDF" in sequence.
> 
> So do you mean:
> 
> xl pci-detach $DOMID $VF_BDF1
> xl pci-detach $DOMID $VF_BDF2
> xl pci-detach $DOMID $VF_BDF3
> xl pci-attach $DOMID $VF_BDF1
> xl pci-attach $DOMID $VF_BDF2
> xl pci-attach $DOMID $VF_BDF3
> 
> ?

I know this bug, I had a patch to fix a similar bug,  I think Jianzhong means:

xl pci-detach $DOMID $VF_BDF1
xl pci-attach $DOMID $VF_BDF1
xl pci-detach $DOMID $VF_BDF1
xl pci-attach $DOMID $VF_BDF1
...

Liang