[PATCH 2/2] docs: Improve zPCI section in pci-addresses.rst
cohuck at redhat.com
Thu Apr 16 16:14:59 UTC 2020
On Thu, 16 Apr 2020 17:56:18 +0200
Boris Fiuczynski <fiuczy at linux.ibm.com> wrote:
> Improving the zPCI example by choosing more distinct values and
> adding explanation for fid.
> Signed-off-by: Boris Fiuczynski <fiuczy at linux.ibm.com>
> docs/pci-addresses.rst | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
> diff --git a/docs/pci-addresses.rst b/docs/pci-addresses.rst
> index 7c8e9edd73..4492389da5 100644
> --- a/docs/pci-addresses.rst
> +++ b/docs/pci-addresses.rst
> @@ -176,14 +176,14 @@ In the simplest case, the following XML snippet
> <model name='pci-bridge'/>
> <target chassisNr='1'/>
> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'>
> - <zpci uid='0x0002' fid='0x00000001'/>
> + <zpci uid='0x0001' fid='0x00000000'/>
Why this change? The pci-bridge does not show up in the guest anyway.
> <interface type='bridge'>
> <source bridge='virbr0'/>
> <model type='virtio'/>
> <address type='pci' domain='0x0000' bus='0x01' slot='0x01' function='0x0'>
> - <zpci uid='0x0001' fid='0x00000000'/>
> + <zpci uid='0x0007' fid='0x00000003'/>
> @@ -191,21 +191,22 @@ will result in the following in a Linux guest:
> - 0001:00:00.0 Ethernet controller: Red Hat, Inc. Virtio network device
> + 0007:00:00.0 Ethernet controller: Red Hat, Inc. Virtio network device
> Note that the PCI bridge is not visible in the guest; s390x always has a flat
> +topology. Also ``fid`` does not define slot or function of the PCI address.
I find the sentence regarding 'fid' confusing. Maybe instead move up
the explanation from below regarding uid and fid?
"The PCI address in the guest is generated from..."
> Neither are any changes in the PCI address visible in the guest; replacing
The 'neither' is now a bit confusing; what about
"Any changes in the PCI address are not visible in the guest..." ?
> the PCI address for the ``virtio-net`` device with
> - <address type='pci' domain='0x0000' bus='0x01' slot='0x07' function='0x3'>
> + <address type='pci' domain='0x0000' bus='0x01' slot='0x06' function='0x4'>
> will result in the exactly same view in the guest, as the addresses there
If you move the fid/uid stuff up, make this
"as the fid and uid values in the zpci element remain unchanged." ?
> -are generated from the information provided via the ``zpci`` element (in
> -fact, from the ``uid``).
> +are generated from the information provided via the ``zpci`` element:
> +the ``uid`` is used as PCI domain, and the ``fid`` is used as the PCI devices
> +slot in the sysfs.
s/the sysfs./sysfs (it does not influence the PCI device address.)/
> Device assignment
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