libvirt users - Dec 2013 - Re: How to Position a Network Interface in Physical PCI Slot

Hi ,

I would like to assign a Network Interface card to Physical Slot X in the
virtual machine,

I have gone through the XML file definition[Now i have some idea on how to
position the Network Interface in Logical PCI Slot.]

I am NOT interested in using a PCI Pass-through from the Host.

currently running  Fedora 19  with libvirt 1.2.0

I would like to create an network interface card on Physical Slot 5 so all
my network interfaces under the pci-bridge get detected as pci5px

Regards
Thiru

On 12/17/2013 08:02 AM, Thiru Murugan wrote:
> Hi ,
>
> I would like to assign a Network Interface card to Physical Slot X in
> the virtual machine,
>
> I have gone through the XML file definition[Now i have some idea on
> how to position the Network Interface in Logical PCI Slot.]
What is logical slot X vs. physical slot X? There are only two PCI
addresses associated with any PCI passthrough device (the slot on the
host, and the slot on the guest), which you say you aren't interested in
anyway, and there is only one PCI address associated with any emulated
device - the slot on the guest, which is set with the <address>
sub-element of any device. In general, whatever address you set there
will be the location of the device on the guest, although I've heard
some people mention that this isn't necessarily always the case, but
depends on the guest OS.

>  
>
> I am NOT interested in using a PCI Pass-through from the Host.
>
> currently running  Fedora 19  with libvirt 1.2.0
>
> I would like to create an network interface card on Physical Slot 5 so
> all my network interfaces under the pci-bridge get detected as pci5px
This should place the card in slot 5 of bus 0:

    <interface type=....>
      ...
      <address type='pci' domain='0' bus='0'
slot='5' function='0'/>
    </interface>

Showing up on a particular slot doesn't necessarily guarantee the name
that will be given to the interface - that is completely up to the guest
OS. For example, on my F19 hardware, I have an ethernet at bus=4 slot=0
function=0 which was given the name "p13p1", another at 4:0.1 which is
"p13p2", and another that is integrated on the motherboard at 6:0.0
which is named "p32p1". On several F19 guests (some installed with F19
from scratch, at least one upgraded from F18), the network interfaces
are all named ethX. I believe this is now somehow controlled by systemd,
but I haven't had any need to learn the details.

Physical Slot -
root@tchp2083 # dmidecode -t slot
~~~~~
Handle 0x0901, DMI type 9, 17 bytes
System Slot Information
        Designation: PCI-E Slot 1
        Type: x8 PCI Express
        Current Usage: In Use
        Length: Long
        ID: 1
        Characteristics:
                3.3 V is provided
                PME signal is supported
        Bus Address: 0000:07:00.0

Logical PCI Slot:
root@tchp2083 # lspci -tv
-[0000:00]-+-00.0  Intel Corporation 5520 I/O Hub to ESI Port
           +-01.0-[04]----00.0  Hewlett-Packard Company Smart Array G6
controllers
           +-02.0-[05]--
           +-03.0-[11-14]----00.0-[12-14]--+-02.0-[13]--+-00.0  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
           |                               |            \-00.1  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
           |                               \-04.0-[14]--+-00.0  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
           |                                            \-00.1  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
           +-09.0-[07-0a]----00.0-[08-0a]--+-02.0-[09]--+-00.0  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
           |                               |            \-00.1  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
           |                               \-04.0-[0a]--+-00.0  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
           |                                            \-00.1  Intel
Corporation 82571EB Gigabit Ethernet Controller (Copper)
~~~~

Equivalent Logical Slot for "Physical Slot 1 " is under domain 0x0000
,Bus
0x00,Slot 0x09,Index[Bridge] 0x07

The Application has been hosted on VMware.
To maintain a Standard ,the Application has Defined Network Interfaces [for
LAN segregation/functions & automation]

Currently I am trying to bring the Application on KVM,and the Network
Interfaces have to be in a certain location for the Automation to work
properly.

I need to have these Network Interfaces -pci2p1,pci2p2 & pci3p1,pci3p2.

Regards
Thiru


On Tue, Dec 17, 2013 at 8:08 PM, Laine Stump <laine@laine.org> wrote:
> On 12/17/2013 08:02 AM, Thiru Murugan wrote:
> > Hi ,
> >
> > I would like to assign a Network Interface card to Physical Slot X in
> > the virtual machine,
> >
> > I have gone through the XML file definition[Now i have some idea on
> > how to position the Network Interface in Logical PCI Slot.]
>
> What is logical slot X vs. physical slot X? There are only two PCI
> addresses associated with any PCI passthrough device (the slot on the
> host, and the slot on the guest), which you say you aren't interested
in
> anyway, and there is only one PCI address associated with any emulated
> device - the slot on the guest, which is set with the <address>
> sub-element of any device. In general, whatever address you set there
> will be the location of the device on the guest, although I've heard
> some people mention that this isn't necessarily always the case, but
> depends on the guest OS.
>
>
> >
> >
> > I am NOT interested in using a PCI Pass-through from the Host.
> >
> > currently running  Fedora 19  with libvirt 1.2.0
> >
> > I would like to create an network interface card on Physical Slot 5 so
> > all my network interfaces under the pci-bridge get detected as pci5px
>
> This should place the card in slot 5 of bus 0:
>
>     <interface type=....>
>       ...
>       <address type='pci' domain='0' bus='0'
slot='5' function='0'/>
>     </interface>
>
> Showing up on a particular slot doesn't necessarily guarantee the name
> that will be given to the interface - that is completely up to the guest
> OS. For example, on my F19 hardware, I have an ethernet at bus=4 slot=0
> function=0 which was given the name "p13p1", another at 4:0.1
which is
> "p13p2", and another that is integrated on the motherboard at
6:0.0
> which is named "p32p1". On several F19 guests (some installed
with F19
> from scratch, at least one upgraded from F18), the network interfaces
> are all named ethX. I believe this is now somehow controlled by systemd,
> but I haven't had any need to learn the details.
>