On 4/15/20 7:47 PM, Cornelia Huck wrote:
On Wed, 15 Apr 2020 19:31:36 +0200 Andrea Bolognani <abologna@redhat.com> wrote:
The idea behind this document is to show, with actual examples, that users should not expect PCI addresses in the domain XML and in the guest OS to match.
The first zPCI example already serves this purpose perfectly, so in the interest of keeping the page as brief and easy to digest as possible the second one is removed.
Signed-off-by: Andrea Bolognani <abologna@redhat.com> --- docs/pci-addresses.rst | 19 ------------------- 1 file changed, 19 deletions(-)
diff --git a/docs/pci-addresses.rst b/docs/pci-addresses.rst index 86a41df6ce..1d2dc8e5fc 100644 --- a/docs/pci-addresses.rst +++ b/docs/pci-addresses.rst @@ -204,25 +204,6 @@ will result in the exactly same view in the guest, as the addresses there are generated from the information provided via the ``zpci`` element (in fact, from the ``uid``).
-Therefore, replacing the virtio-net device definition with the following XML -snippet - -:: - - <interface type='bridge'> - <source bridge='virbr0'/> - <model type='virtio'/> - <address type='pci' domain='0x0000' bus='0x01' slot='0x07' function='0x3'> - <zpci uid='0x0007' fid='0x00000003'/> - </address> - </interface> - -will yield the following result in a Linux guest: - -:: - - 0007:00:00.0 Ethernet controller: Red Hat, Inc. Virtio network device - I suggest to use the zpci addressing from the removed example because it outlines more clearly the differences in the parameters. Something like the example below:
For s390x machines, PCI addresses are handled yet differently. No topology information is relayed in the PCI addresses; instead, the fid and uid elements of the zpci device convey information. In the simplest case, the following XML snippet <controller type='pci' index='0' model='pci-root'/> <controller type='pci' index='1' model='pci-bridge'> <model name='pci-bridge'/> <target chassisNr='1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'> <zpci uid='0x0001' fid='0x00000000'/> </address> </controller> <interface type='bridge'> <mac address='02:ca:fe:fa:ce:04'/> <source bridge='virbr0'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x01' slot='0x01' function='0x0'> <zpci uid='0x0007' fid='0x00000003'/> </address> </interface> will result in the following in a Linux guest: 0007:00:00.0 Ethernet controller: Red Hat, Inc. Virtio network device The slot for the PCI device in the guest OS is defined by the fid (function id).
Device assignment =================
Hm, should that rather go somewhere else? What I wanted to show is "you can have the same PCI address in the XML and still get a different PCI address in the guest, if you change the zpci values", as that might be another source of confusion.
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