User Manual

Rev 2.0-3.0.0

Mellanox Technologies

• Each vHCA port has its own virtual port state

A vHCA port is up if the following conditions apply:

• The physical port is up

• The virtual GID table contains the GIDs requested by the host admin

• The SM has acknowledged the requested GIDs since the last time that the physical port

went up

• Other port attributes are shared, such as: GID prefix, LID, SM LID, LMC mask

To allow the host admin to control the virtual GID and PKey tables of vHCAs, a new sysfs 'iov'

sub-tree has been added under the PF InfiniBand device.

4.13.7.2.1SRIOV sysfs Administration Interfaces on the Hypervisor

Administration of GUIDs and PKeys is done via the sysfs interface in the Hypervisor (Dom0).

This interface is under:

Under this directory, the following subdirectories can be found:

•

ports - The actual (physical) port resource tables

Port GID tables:

• ports/<n>/gids/<n> where 0 <= n <= 127 (the physical port gids)

• ports/<n>/admin_guids/<n> where 0 <= n <= 127 (allows examining or changing the

administrative state of a given GUID>

• ports/<n>/pkeys/<n> where 0 <= n <= 126 (displays the contents of the physical pkey

table)

• <pci id> directories - one for Dom0 and one per guest. Here, you may see the map-

ping between virtual and physical pkey indices, and the virtual to physical gid 0.

Currently, the GID mapping cannot be modified, but the pkey virtual to physical mapping can .

These directories have the structure:

• <pci_id>/port/<m>/gid_idx/0 where m = 1..2 (this is read-only)

and

• <pci_id>/port/<m>/pkey_idx/<n>, where m = 1..2 and n = 0..126

For instructions on configuring pkey_idx, please see below.

4.13.7.2.2Configuring an Alias GUID (under ports/<n>/admin_guids)

Step 1. Determine the GUID index of the PCI Virtual Function that you want to pass through to a

guest.

For example, if you want to pass through PCI function 02:00.3 to a certain guest, you initially

need to see which GUID index is used for this function.

To do so:

The value returned will present which guid index to modify on Dom0.

Step 2. Modify the physical GUID table via the admin_guids sysfs interface.

/sys/class/infiniband/<infiniband device>/iov

cat /sys/class/infiniband/iov/0000:02:00.3/port/<port_num>/gid_idx/0