5:04 a.m.
Hi,
I was looking on the output of virsh nodedev-dumpxml on a PCI to see if it has SR-IOV PF
capability.
It seem that if the virtual functions are enables the xml look like [1] but if the PCI has
no VFs enabled the
output is like in [2].
As you can see for PCI which has no VFs the <capability
type='virt_functions'> tag doen't exist.
Is this by design?
I would except that <capability type='virt_functions'/> tag with empty
elements will also be include in that case.
Thanks,
Moshe Levi.
[1] root@r-ufm152:~# virsh nodedev-dumpxml pci_0000_03_00_0
<device>
<name>pci_0000_03_00_0</name>
<path>/sys/devices/pci0000:00/0000:00:02.0/0000:03:00.0</path>
<parent>pci_0000_00_02_0</parent>
<driver>
<name>mlx5_core</name>
</driver>
<capability type='pci'>
<domain>0</domain>
<bus>3</bus>
<slot>0</slot>
<function>0</function>
<product id='0x1013'>MT27700 Family [ConnectX-4]</product>
<vendor id='0x15b3'>Mellanox Technologies</vendor>
<capability type='virt_functions'>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x2'/>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x3'/>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x4'/>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x5'/>
</capability>
<iommuGroup number='15'>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x0'/>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x1'/>
</iommuGroup>
<numa node='0'/>
<pci-express>
<link validity='cap' port='0' speed='8'
width='16'/>
<link validity='sta' speed='8' width='16'/>
</pci-express>
</capability>
</device>
[2] root@r-ufm152:~# virsh nodedev-dumpxml pci_0000_03_00_1
<device>
<name>pci_0000_03_00_1</name>
<path>/sys/devices/pci0000:00/0000:00:02.0/0000:03:00.1</path>
<parent>pci_0000_00_02_0</parent>
<driver>
<name>mlx5_core</name>
</driver>
<capability type='pci'>
<domain>0</domain>
<bus>3</bus>
<slot>0</slot>
<function>1</function>
<product id='0x1013'>MT27700 Family [ConnectX-4]</product>
<vendor id='0x15b3'>Mellanox Technologies</vendor>
<iommuGroup number='15'>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x0'/>
<address domain='0x0000' bus='0x03' slot='0x00'
function='0x1'/>
</iommuGroup>
<numa node='0'/>
<pci-express>
<link validity='cap' port='0' speed='8'
width='16'/>
<link validity='sta' speed='8' width='16'/>
</pci-express>
</capability>
</device>
4:05 a.m.
On Sun, Nov 22, 2015 at 11:04:28AM +0000, Moshe Levi wrote:
Hi,
I was looking on the output of virsh nodedev-dumpxml on a PCI to see if it has SR-IOV PF
capability.
It seem that if the virtual functions are enables the xml look like [1] but if the PCI
has no VFs enabled the
output is like in [2].
As you can see for PCI which has no VFs the <capability
type='virt_functions'> tag doen't exist.
Is this by design?
I would except that <capability type='virt_functions'/> tag with empty
elements will also be include in that case.
That is an bug. The capability should be reported regardless of whether
any are VFs currently enabled, so we should fix this.
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 :|
9:34 a.m.
On 11/23/2015 05:05 AM, Daniel P. Berrange wrote:
On Sun, Nov 22, 2015 at 11:04:28AM +0000, Moshe Levi wrote:
> Hi,
>
> I was looking on the output of virsh nodedev-dumpxml on a PCI to see if it has SR-IOV
PF capability.
> It seem that if the virtual functions are enables the xml look like [1] but if the
PCI has no VFs enabled the
> output is like in [2].
> As you can see for PCI which has no VFs the <capability
type='virt_functions'> tag doen't exist.
> Is this by design?
> I would except that <capability type='virt_functions'/> tag with empty
elements will also be include in that case.
That is an bug. The capability should be reported regardless of whether
any are VFs currently enabled, so we should fix this.
Prior to libvirt 1.0.4, "<capability type='virt_functions'>" was
there
for every PCI device regardless of whether or not it had the ability to
have virtual functions. It looks like commit 9a3ff01d changed it to only
emit that element when there was at least one VF. So it used to be
wrong, and now it is wrong in a different way :-)
If we're going to switch to emiting virt_functions whenever a device has
the potential to provide VFs, we may as well make it worthwhile and also
emit the maximum possible VFs for the device, maybe simply:
<capability type='virt_functions' maxCount='7'>
(the current count is implicit in the number of entries in the list that
follows. I don't have an opinion on whether it is better to also include
explicitly with, e.g. "count='7'", or just leave it implicit).
9:40 a.m.
On Mon, Nov 23, 2015 at 10:34:43AM -0500, Laine Stump wrote:
On 11/23/2015 05:05 AM, Daniel P. Berrange wrote:
>On Sun, Nov 22, 2015 at 11:04:28AM +0000, Moshe Levi wrote:
>>Hi,
>>
>>I was looking on the output of virsh nodedev-dumpxml on a PCI to see if it has
SR-IOV PF capability.
>>It seem that if the virtual functions are enables the xml look like [1] but if
the PCI has no VFs enabled the
>>output is like in [2].
>>As you can see for PCI which has no VFs the <capability
type='virt_functions'> tag doen't exist.
>>Is this by design?
>>I would except that <capability type='virt_functions'/> tag with
empty elements will also be include in that case.
>That is an bug. The capability should be reported regardless of whether
>any are VFs currently enabled, so we should fix this.
Prior to libvirt 1.0.4, "<capability type='virt_functions'>" was
there for
every PCI device regardless of whether or not it had the ability to have
virtual functions. It looks like commit 9a3ff01d changed it to only emit
that element when there was at least one VF. So it used to be wrong, and now
it is wrong in a different way :-)
Awesome.
If we're going to switch to emiting virt_functions whenever a
device has the
potential to provide VFs, we may as well make it worthwhile and also emit
the maximum possible VFs for the device, maybe simply:
<capability type='virt_functions' maxCount='7'>
(the current count is implicit in the number of entries in the list that
follows. I don't have an opinion on whether it is better to also include
explicitly with, e.g. "count='7'", or just leave it implicit).
Is there any way for us to actually discover the max count ? If so, then
it seems nice to include it.
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 :|
10:26 a.m.
On 11/23/2015 10:40 AM, Daniel P. Berrange wrote:
On Mon, Nov 23, 2015 at 10:34:43AM -0500, Laine Stump wrote:
> If we're going to switch to emiting virt_functions whenever a device has the
> potential to provide VFs, we may as well make it worthwhile and also emit
> the maximum possible VFs for the device, maybe simply:
>
> <capability type='virt_functions' maxCount='7'>
>
> (the current count is implicit in the number of entries in the list that
> follows. I don't have an opinion on whether it is better to also include
> explicitly with, e.g. "count='7'", or just leave it implicit).
Is there any way for us to actually discover the max count ? If so, then
it seems nice to include it.
Yes. I don't know if it existed back when that code was originally
added, but at least RHEL6.7 (the oldest OS I have running on a machine
with an SRIOV-capable card) and later have two files in the device's
sysfs, sriov_numvfs and sriov_totalvfs. The former is the number that
are currently active, and the latter is the maximum possible for this PF.
(On a related topic - you can change the number of currently active VFs
by writing "0" to sriov_numvfs then writing the desired number to it;
this does temporarily delete any VFs that are already active though, so
it can only be done if none are in use. I've planned to hook libvirt
networks up to this so that VFs can be enabled completely within libvirt
(since the driver commandline method isn't consistent between different
vendors, and I believe is now considered to be deprecated). Since
Openstack doesn't use libvirt networks but may want similar
functionality, I'm wondering where would be a good place to do that. We
could provide something via the node-device API, but that couldn't be
automatically done by libvirtd at startup; alternately Openstack could
create a network but not use it, but that just seems conceptually
confusing even though it would work.)
10:28 a.m.
On Mon, Nov 23, 2015 at 11:26:11AM -0500, Laine Stump wrote:
On 11/23/2015 10:40 AM, Daniel P. Berrange wrote:
>On Mon, Nov 23, 2015 at 10:34:43AM -0500, Laine Stump wrote:
>
>>If we're going to switch to emiting virt_functions whenever a device has the
>>potential to provide VFs, we may as well make it worthwhile and also emit
>>the maximum possible VFs for the device, maybe simply:
>>
>> <capability type='virt_functions' maxCount='7'>
>>
>>(the current count is implicit in the number of entries in the list that
>>follows. I don't have an opinion on whether it is better to also include
>>explicitly with, e.g. "count='7'", or just leave it implicit).
>Is there any way for us to actually discover the max count ? If so, then
>it seems nice to include it.
Yes. I don't know if it existed back when that code was originally added,
but at least RHEL6.7 (the oldest OS I have running on a machine with an
SRIOV-capable card) and later have two files in the device's sysfs,
sriov_numvfs and sriov_totalvfs. The former is the number that are currently
active, and the latter is the maximum possible for this PF.
(On a related topic - you can change the number of currently active VFs by
writing "0" to sriov_numvfs then writing the desired number to it; this does
temporarily delete any VFs that are already active though, so it can only be
done if none are in use. I've planned to hook libvirt networks up to this so
that VFs can be enabled completely within libvirt (since the driver
commandline method isn't consistent between different vendors, and I believe
is now considered to be deprecated). Since Openstack doesn't use libvirt
networks but may want similar functionality, I'm wondering where would be a
good place to do that. We could provide something via the node-device API,
but that couldn't be automatically done by libvirtd at startup; alternately
Openstack could create a network but not use it, but that just seems
conceptually confusing even though it would work.)
There is scope to extend node device APIs to allow definition of persistent
config for virtual devices. We have similar scenario wrt NPIV devices which
are dynamically allocatable
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 :|
1:23 p.m.
Hi Laine,
Did you have a bug for this issue?
I need it to document it in for my workaround in OpenStack.
Thanks,
Moshe Levi.
-----Original Message-----
From: Daniel P. Berrange [mailto:berrange@redhat.com]
Sent: Monday, November 23, 2015 6:29 PM
To: Laine Stump <laine(a)laine.org>
Cc: libvir-list(a)redhat.com; Moshe Levi <moshele(a)mellanox.com>
Subject: Re: [libvirt] how to know if PCI device has SR-IOV PF capability
On Mon, Nov 23, 2015 at 11:26:11AM -0500, Laine Stump wrote:
> On 11/23/2015 10:40 AM, Daniel P. Berrange wrote:
> >On Mon, Nov 23, 2015 at 10:34:43AM -0500, Laine Stump wrote:
> >
> >>If we're going to switch to emiting virt_functions whenever a device
> >>has the potential to provide VFs, we may as well make it worthwhile
> >>and also emit the maximum possible VFs for the device, maybe simply:
> >>
> >> <capability type='virt_functions' maxCount='7'>
> >>
> >>(the current count is implicit in the number of entries in the list
> >>that follows. I don't have an opinion on whether it is better to
> >>also include explicitly with, e.g. "count='7'", or just
leave it implicit).
> >Is there any way for us to actually discover the max count ? If so,
> >then it seems nice to include it.
>
> Yes. I don't know if it existed back when that code was originally
> added, but at least RHEL6.7 (the oldest OS I have running on a machine
> with an SRIOV-capable card) and later have two files in the device's
> sysfs, sriov_numvfs and sriov_totalvfs. The former is the number that
> are currently active, and the latter is the maximum possible for this PF.
>
> (On a related topic - you can change the number of currently active
> VFs by writing "0" to sriov_numvfs then writing the desired number to
> it; this does temporarily delete any VFs that are already active
> though, so it can only be done if none are in use. I've planned to
> hook libvirt networks up to this so that VFs can be enabled completely
> within libvirt (since the driver commandline method isn't consistent
> between different vendors, and I believe is now considered to be
> deprecated). Since Openstack doesn't use libvirt networks but may want
> similar functionality, I'm wondering where would be a good place to do
> that. We could provide something via the node-device API, but that
> couldn't be automatically done by libvirtd at startup; alternately
> Openstack could create a network but not use it, but that just seems
> conceptually confusing even though it would work.)
There is scope to extend node device APIs to allow definition of persistent
config for virtual devices. We have similar scenario wrt NPIV devices which are
dynamically allocatable
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 :|
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6 comments
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Moshe Levi