From: Cornelia Huck <cohuck@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Pierre Morel <pmorel@linux.ibm.com>,
alex.williamson@redhat.com, linux-kernel@vger.kernel.org,
linux-s390@vger.kernel.org, kvm@vger.kernel.org,
frankja@linux.ibm.com, akrowiak@linux.ibm.com,
pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com, freude@linux.ibm.com,
mimu@linux.ibm.com
Subject: Re: [PATCH v3 1/9] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
Date: Thu, 14 Feb 2019 16:40:44 +0100 [thread overview]
Message-ID: <20190214164044.5e67660a.cohuck@redhat.com> (raw)
In-Reply-To: <6147f1ce-fd8b-1ec2-30ce-7ac68f3d8e27@de.ibm.com>
On Thu, 14 Feb 2019 16:05:35 +0100
Christian Borntraeger <borntraeger@de.ibm.com> wrote:
> On 14.02.2019 15:54, Cornelia Huck wrote:
> > On Thu, 14 Feb 2019 14:51:01 +0100
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
>
> Pierre,
> this is independent from this series and should have been sent separately.
> In the end (when we have the final solution) this will require cc stable.
> >
> >> Libudev relies on having a subsystem link for non-root devices. To
> >> avoid libudev (and potentially other userspace tools) choking on the
> >> matrix device let us introduce a vfio_ap bus and with that the vfio_ap
> >> bus subsytem, and make the matrix device reside within it.
> >
> > How does libudev choke on this? It feels wrong to introduce a bus that
> > basically does nothing...
>
> I have seen libvirt looping when a matrix device was available before the
> libvirt start.
> Marc Hartmayer debugged this and circumvented this in libvirt:
> https://www.redhat.com/archives/libvir-list/2019-February/msg00837.html
>
> Still libudev expects a subsystem link in the matrix folder when doing the
> udev_enumerate_scan_devices call.
>
> Having a bus is one way of adding a subsystem link.
Ugh, that feels really broken. Adding a bus is probably the easiest way
to get this working, though :/
next prev parent reply other threads:[~2019-02-14 15:40 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-14 13:51 [PATCH v3 0/9] [RFC] vfio: ap: ioctl definitions for AP Queue Interrupt Control Pierre Morel
2019-02-14 13:51 ` [PATCH v3 1/9] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem Pierre Morel
2019-02-14 14:54 ` Cornelia Huck
2019-02-14 15:05 ` Christian Borntraeger
2019-02-14 15:40 ` Cornelia Huck [this message]
2019-02-14 17:12 ` Tony Krowiak
2019-02-14 17:35 ` Pierre Morel
2019-02-14 15:47 ` Pierre Morel
2019-02-14 16:57 ` Cornelia Huck
2019-02-14 17:36 ` Pierre Morel
2019-02-14 18:30 ` Tony Krowiak
2019-02-15 9:11 ` Cornelia Huck
2019-02-15 21:59 ` Tony Krowiak
2019-02-18 12:01 ` Cornelia Huck
2019-02-18 16:35 ` Tony Krowiak
2019-02-18 16:57 ` Cornelia Huck
2019-02-19 22:27 ` Tony Krowiak
2019-02-20 9:05 ` Cornelia Huck
2019-02-14 15:01 ` Christian Borntraeger
2019-02-14 15:09 ` Pierre Morel
2019-02-14 13:51 ` [PATCH v3 2/9] s390: ap: kvm: setting a hook for PQAP instructions Pierre Morel
2019-02-14 15:54 ` Cornelia Huck
2019-02-14 16:45 ` Pierre Morel
2019-02-15 9:26 ` Cornelia Huck
2019-02-15 9:55 ` Pierre Morel
2019-02-15 22:02 ` Tony Krowiak
2019-02-18 18:29 ` Pierre Morel
2019-02-18 22:42 ` Cornelia Huck
2019-02-19 19:50 ` Pierre Morel
2019-02-19 22:36 ` Tony Krowiak
2019-02-21 12:40 ` Pierre Morel
2019-02-19 22:50 ` Tony Krowiak
2019-02-14 13:51 ` [PATCH v3 3/9] s390: ap: new vfio_ap_queue structure Pierre Morel
2019-02-15 9:37 ` Cornelia Huck
2019-02-15 9:58 ` Pierre Morel
2019-02-14 13:51 ` [PATCH v3 4/9] s390: ap: tools to find a queue with a specific APQN Pierre Morel
2019-02-15 9:49 ` Cornelia Huck
2019-02-15 10:10 ` Pierre Morel
2019-02-15 10:24 ` Cornelia Huck
2019-02-15 22:13 ` Tony Krowiak
2019-02-18 12:21 ` Cornelia Huck
2019-02-18 18:32 ` Pierre Morel
2019-02-22 15:04 ` Tony Krowiak
2019-02-14 13:51 ` [PATCH v3 5/9] s390: ap: tools to associate a queue to a matrix Pierre Morel
2019-02-15 22:30 ` Tony Krowiak
2019-02-18 18:36 ` Pierre Morel
2019-02-14 13:51 ` [PATCH v3 6/9] vfio: ap: register IOMMU VFIO notifier Pierre Morel
2019-02-15 22:55 ` Tony Krowiak
2019-02-19 9:59 ` Halil Pasic
2019-02-19 19:04 ` Pierre Morel
2019-02-19 21:33 ` Tony Krowiak
2019-02-19 18:51 ` Pierre Morel
2019-02-14 13:51 ` [PATCH v3 7/9] s390: ap: implement PAPQ AQIC interception in kernel Pierre Morel
2019-02-15 23:11 ` Tony Krowiak
2019-02-19 19:16 ` Pierre Morel
2019-02-20 11:54 ` Halil Pasic
2019-02-21 12:50 ` Pierre Morel
2019-02-14 13:51 ` [PATCH v3 8/9] s390: ap: Cleanup on removing the AP device Pierre Morel
2019-02-15 23:29 ` Tony Krowiak
2019-02-19 19:29 ` Pierre Morel
2019-02-15 23:36 ` Tony Krowiak
2019-02-19 19:41 ` Pierre Morel
2019-02-14 13:51 ` [PATCH v3 9/9] s390: ap: kvm: add AP Queue Interruption Control facility Pierre Morel
2019-02-14 20:33 ` [PATCH v3 0/9] [RFC] vfio: ap: ioctl definitions for AP Queue Interrupt Control Tony Krowiak
2019-02-15 8:44 ` Pierre Morel
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