12:19 a.m.
On 09/19/2011 01:32 PM, Daniel P. Berrange wrote:
On Mon, Sep 19, 2011 at 07:16:22PM +0200, Marc-André Lureau wrote:
> Hi hi
>
> On Fri, Sep 16, 2011 at 1:38 PM, Marc-André Lureau<mlureau(a)redhat.com> wrote:
>>>> How do we allow other devices to share the slot? It seems to me that
>>>> qemuDomainPCIAddressSetNextAddr() only allocate whole slot, while
>>>> making sure there is no conflicts on the same slot.
>>> So, if the user wants to use multi function pci device, he should
>>> specify the
>>> pci address.
>> So adding a check such as:
>>
>> if (!multiFunc&& info->addr.pci.function != 0)
>> return error("The %s device doesn't support multifunction
address")
>>
> Wen, does that sound reasonable to you?
>
> Daniel, did you had time to verify that PCI allocation is per-slot?
>
> (It would be nice to get this "workaround" for the next release)
IMHO this kind of hack doesn't belong in libvirt. It is fine for distro
vendors to consider as a one off quick-hack for their packages of libvirt,
if they don't have time to fix the real QXL bug, but not for libvirt
upstream releases. QXL/QEMU should really be fixed since that's where the
problem appears to lie.
As it stands, Fedora 16 (currently using unpatched libvirt-0.9.6) will
be going into beta with QXL video broken for Windows guests, so we need
some kind of Fedora-only patch very soon (see the schedule here:
https://fedoraproject.org/wiki/Releases/16/Schedule - fortunately just
delayed another week)
The original patch in this thread:
https://www.redhat.com/archives/libvir-list/2011-September/msg00534.html
of course doesn't include the above mentioned additional code, and there
isn't a followup patch. It would be very good to push a patch to the F16
git for this so it would hopefully get into the beta, but want to make
sure what I push is the "right" thing, so a "final" patch (and some
testing by people with F16 hosts) would be very helpful!
4:13 a.m.
New subject: [libvirt] [PATCH] qemu: qxl devices don't support multifunction yet
On Tue, Sep 27, 2011 at 01:19:20AM -0400, Laine Stump wrote:
On 09/19/2011 01:32 PM, Daniel P. Berrange wrote:
>On Mon, Sep 19, 2011 at 07:16:22PM +0200, Marc-André Lureau wrote:
>>Hi hi
>>
>>On Fri, Sep 16, 2011 at 1:38 PM, Marc-André Lureau<mlureau(a)redhat.com>
wrote:
>>>>>How do we allow other devices to share the slot? It seems to me that
>>>>>qemuDomainPCIAddressSetNextAddr() only allocate whole slot, while
>>>>>making sure there is no conflicts on the same slot.
>>>>So, if the user wants to use multi function pci device, he should
>>>>specify the
>>>>pci address.
>>>So adding a check such as:
>>>
>>>if (!multiFunc&& info->addr.pci.function != 0)
>>> return error("The %s device doesn't support multifunction
address")
>>>
>>Wen, does that sound reasonable to you?
>>
>>Daniel, did you had time to verify that PCI allocation is per-slot?
>>
>>(It would be nice to get this "workaround" for the next release)
>IMHO this kind of hack doesn't belong in libvirt. It is fine for distro
>vendors to consider as a one off quick-hack for their packages of libvirt,
>if they don't have time to fix the real QXL bug, but not for libvirt
>upstream releases. QXL/QEMU should really be fixed since that's where the
>problem appears to lie.
As it stands, Fedora 16 (currently using unpatched libvirt-0.9.6)
will be going into beta with QXL video broken for Windows guests, so
we need some kind of Fedora-only patch very soon (see the schedule
here: https://fedoraproject.org/wiki/Releases/16/Schedule -
fortunately just delayed another week)
The original patch in this thread:
https://www.redhat.com/archives/libvir-list/2011-September/msg00534.html
of course doesn't include the above mentioned additional code, and
there isn't a followup patch. It would be very good to push a patch
to the F16 git for this so it would hopefully get into the beta, but
want to make sure what I push is the "right" thing, so a "final"
patch (and some testing by people with F16 hosts) would be very
helpful!
When we originally enabled multifunction for all PCI devices, we did so
in the belief that this was effectively a no-op for guest OSes. ie it
should not have changed guest OS behaviour at all, unless multiple devices
were actually inserted in the slot.
Evidentally this turns out to be incorrect. In other words we introduced
a guest ABI change. This is very bad, because our stated goal is to have
a stable guest ABI across libvirt & QEMU releases.
Thus IMHO we need to disable *all* setting of the 'multifunction=on'
parameter for all guests by default, to unbreak the ABI compatibility.
Then we should introduce a new parameter 'multifunction='on' in the
<address type=pci> element to allow it to be optionally enabled per
device.
Regards,
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
2:02 a.m.
New subject: [libvirt] [PATCH] qemu: qxl devices don't support multifunction yet
On 09/27/2011 05:13 AM, Daniel P. Berrange wrote:
On Tue, Sep 27, 2011 at 01:19:20AM -0400, Laine Stump wrote:
> On 09/19/2011 01:32 PM, Daniel P. Berrange wrote:
>> On Mon, Sep 19, 2011 at 07:16:22PM +0200, Marc-André Lureau wrote:
>>> Hi hi
>>>
>>> On Fri, Sep 16, 2011 at 1:38 PM, Marc-André Lureau<mlureau(a)redhat.com>
wrote:
>>>>>> How do we allow other devices to share the slot? It seems to me
that
>>>>>> qemuDomainPCIAddressSetNextAddr() only allocate whole slot,
while
>>>>>> making sure there is no conflicts on the same slot.
>>>>> So, if the user wants to use multi function pci device, he should
>>>>> specify the
>>>>> pci address.
>>>> So adding a check such as:
>>>>
>>>> if (!multiFunc&& info->addr.pci.function != 0)
>>>> return error("The %s device doesn't support multifunction
address")
>>>>
>>> Wen, does that sound reasonable to you?
>>>
>>> Daniel, did you had time to verify that PCI allocation is per-slot?
>>>
>>> (It would be nice to get this "workaround" for the next release)
>> IMHO this kind of hack doesn't belong in libvirt. It is fine for distro
>> vendors to consider as a one off quick-hack for their packages of libvirt,
>> if they don't have time to fix the real QXL bug, but not for libvirt
>> upstream releases. QXL/QEMU should really be fixed since that's where the
>> problem appears to lie.
> As it stands, Fedora 16 (currently using unpatched libvirt-0.9.6)
> will be going into beta with QXL video broken for Windows guests, so
> we need some kind of Fedora-only patch very soon (see the schedule
> here: https://fedoraproject.org/wiki/Releases/16/Schedule -
> fortunately just delayed another week)
>
> The original patch in this thread:
>
> https://www.redhat.com/archives/libvir-list/2011-September/msg00534.html
>
> of course doesn't include the above mentioned additional code, and
> there isn't a followup patch. It would be very good to push a patch
> to the F16 git for this so it would hopefully get into the beta, but
> want to make sure what I push is the "right" thing, so a "final"
> patch (and some testing by people with F16 hosts) would be very
> helpful!
When we originally enabled multifunction for all PCI devices, we did so
in the belief that this was effectively a no-op for guest OSes. ie it
should not have changed guest OS behaviour at all, unless multiple devices
were actually inserted in the slot.
Evidentally this turns out to be incorrect. In other words we introduced
a guest ABI change. This is very bad, because our stated goal is to have
a stable guest ABI across libvirt& QEMU releases.
Thus IMHO we need to disable *all* setting of the 'multifunction=on'
parameter for all guests by default, to unbreak the ABI compatibility.
Of course this has been in since 0.9.3, meaning there are official
releases with broken ABI compatibility :-(. Still, the sooner it's fixed
the better.
Then we should introduce a new parameter
'multifunction='on' in the
<address type=pci> element to allow it to be optionally enabled per
device.
Will it be acceptable to put that in a patch on top of 0.9.6 for Fedora
16? (I think the answer is "yes", since it's only an XML change, but
just want to make sure).
3:18 a.m.
New subject: [libvirt] [PATCH] qemu: qxl devices don't support multifunction yet
On Wed, Sep 28, 2011 at 03:02:59AM -0400, Laine Stump wrote:
On 09/27/2011 05:13 AM, Daniel P. Berrange wrote:
>On Tue, Sep 27, 2011 at 01:19:20AM -0400, Laine Stump wrote:
>>On 09/19/2011 01:32 PM, Daniel P. Berrange wrote:
>>>On Mon, Sep 19, 2011 at 07:16:22PM +0200, Marc-André Lureau wrote:
>>>>Hi hi
>>>>
>>>>On Fri, Sep 16, 2011 at 1:38 PM, Marc-André
Lureau<mlureau(a)redhat.com> wrote:
>>>>>>>How do we allow other devices to share the slot? It seems to
me that
>>>>>>>qemuDomainPCIAddressSetNextAddr() only allocate whole slot,
while
>>>>>>>making sure there is no conflicts on the same slot.
>>>>>>So, if the user wants to use multi function pci device, he
should
>>>>>>specify the
>>>>>>pci address.
>>>>>So adding a check such as:
>>>>>
>>>>>if (!multiFunc&& info->addr.pci.function != 0)
>>>>> return error("The %s device doesn't support multifunction
address")
>>>>>
>>>>Wen, does that sound reasonable to you?
>>>>
>>>>Daniel, did you had time to verify that PCI allocation is per-slot?
>>>>
>>>>(It would be nice to get this "workaround" for the next
release)
>>>IMHO this kind of hack doesn't belong in libvirt. It is fine for distro
>>>vendors to consider as a one off quick-hack for their packages of libvirt,
>>>if they don't have time to fix the real QXL bug, but not for libvirt
>>>upstream releases. QXL/QEMU should really be fixed since that's where
the
>>>problem appears to lie.
>>As it stands, Fedora 16 (currently using unpatched libvirt-0.9.6)
>>will be going into beta with QXL video broken for Windows guests, so
>>we need some kind of Fedora-only patch very soon (see the schedule
>>here: https://fedoraproject.org/wiki/Releases/16/Schedule -
>>fortunately just delayed another week)
>>
>>The original patch in this thread:
>>
>> https://www.redhat.com/archives/libvir-list/2011-September/msg00534.html
>>
>>of course doesn't include the above mentioned additional code, and
>>there isn't a followup patch. It would be very good to push a patch
>>to the F16 git for this so it would hopefully get into the beta, but
>>want to make sure what I push is the "right" thing, so a
"final"
>>patch (and some testing by people with F16 hosts) would be very
>>helpful!
>When we originally enabled multifunction for all PCI devices, we did so
>in the belief that this was effectively a no-op for guest OSes. ie it
>should not have changed guest OS behaviour at all, unless multiple devices
>were actually inserted in the slot.
>
>Evidentally this turns out to be incorrect. In other words we introduced
>a guest ABI change. This is very bad, because our stated goal is to have
>a stable guest ABI across libvirt& QEMU releases.
>
>Thus IMHO we need to disable *all* setting of the 'multifunction=on'
>parameter for all guests by default, to unbreak the ABI compatibility.
Of course this has been in since 0.9.3, meaning there are official
releases with broken ABI compatibility :-(. Still, the sooner it's
fixed the better.
Fortunately it has only affected guests with a QXL device, to the best
of our knowledge.
>Then we should introduce a new parameter
'multifunction='on' in the
><address type=pci> element to allow it to be optionally enabled per
>device.
Will it be acceptable to put that in a patch on top of 0.9.6 for
Fedora 16? (I think the answer is "yes", since it's only an XML
change, but just want to make sure).
Yep.
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
12:55 a.m.
New subject: [libvirt] [PATCH] qemu: qxl devices don't support multifunction yet
On 09/27/2011 05:13 AM, Daniel P. Berrange wrote:
On Tue, Sep 27, 2011 at 01:19:20AM -0400, Laine Stump wrote:
> On 09/19/2011 01:32 PM, Daniel P. Berrange wrote:
>> On Mon, Sep 19, 2011 at 07:16:22PM +0200, Marc-André Lureau wrote:
>>> Hi hi
>>>
>>> On Fri, Sep 16, 2011 at 1:38 PM, Marc-André Lureau<mlureau(a)redhat.com>
wrote:
>>>>>> How do we allow other devices to share the slot? It seems to me
that
>>>>>> qemuDomainPCIAddressSetNextAddr() only allocate whole slot,
while
>>>>>> making sure there is no conflicts on the same slot.
>>>>> So, if the user wants to use multi function pci device, he should
>>>>> specify the
>>>>> pci address.
>>>> So adding a check such as:
>>>>
>>>> if (!multiFunc&& info->addr.pci.function != 0)
>>>> return error("The %s device doesn't support multifunction
address")
>>>>
>>> Wen, does that sound reasonable to you?
>>>
>>> Daniel, did you had time to verify that PCI allocation is per-slot?
>>>
>>> (It would be nice to get this "workaround" for the next release)
>> IMHO this kind of hack doesn't belong in libvirt. It is fine for distro
>> vendors to consider as a one off quick-hack for their packages of libvirt,
>> if they don't have time to fix the real QXL bug, but not for libvirt
>> upstream releases. QXL/QEMU should really be fixed since that's where the
>> problem appears to lie.
> As it stands, Fedora 16 (currently using unpatched libvirt-0.9.6)
> will be going into beta with QXL video broken for Windows guests, so
> we need some kind of Fedora-only patch very soon (see the schedule
> here: https://fedoraproject.org/wiki/Releases/16/Schedule -
> fortunately just delayed another week)
>
> The original patch in this thread:
>
> https://www.redhat.com/archives/libvir-list/2011-September/msg00534.html
>
> of course doesn't include the above mentioned additional code, and
> there isn't a followup patch. It would be very good to push a patch
> to the F16 git for this so it would hopefully get into the beta, but
> want to make sure what I push is the "right" thing, so a "final"
> patch (and some testing by people with F16 hosts) would be very
> helpful!
When we originally enabled multifunction for all PCI devices, we did so
in the belief that this was effectively a no-op for guest OSes. ie it
should not have changed guest OS behaviour at all, unless multiple devices
were actually inserted in the slot.
Evidentally this turns out to be incorrect. In other words we introduced
a guest ABI change. This is very bad, because our stated goal is to have
a stable guest ABI across libvirt& QEMU releases.
Thus IMHO we need to disable *all* setting of the 'multifunction=on'
parameter for all guests by default, to unbreak the ABI compatibility.
Then we should introduce a new parameter 'multifunction='on' in the
<address type=pci> element to allow it to be optionally enabled per
device.
I just sent a patch to do this, in a separate thread so it doesn't get
buried:
https://www.redhat.com/archives/libvir-list/2011-September/msg01291.html
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