Provided by: freebsd-manpages_12.2-1_all 
NAME
pci_iov_schema, pci_iov_schema_alloc_node, pci_iov_schema_add_bool,
pci_iov_schema_add_string, pci_iov_schema_add_uint8, pci_iov_schema_add_uint16,
pci_iov_schema_add_uint32, pci_iov_schema_add_uint64, pci_iov_schema_add_unicast_mac — PCI
SR-IOV config schema interface
SYNOPSIS
#include <machine/stdarg.h>
#include <sys/nv.h>
#include <sys/iov_schema.h>
nvlist_t *
pci_iov_schema_alloc_node(void);
void
pci_iov_schema_add_bool(nvlist_t *schema, const char *name, uint32_t flags, int defaultVal);
void
pci_iov_schema_add_string(nvlist_t *schema, const char *name, uint32_t flags,
const char *defaultVal);
void
pci_iov_schema_add_uint8(nvlist_t *schema, const char *name, uint32_t flags,
uint8_t defaultVal);
void
pci_iov_schema_add_uint16(nvlist_t *schema, const char *name, uint32_t flags,
uint16_t defaultVal);
void
pci_iov_schema_add_uint32(nvlist_t *schema, const char *name, uint32_t flags,
uint32_t defaultVal);
void
pci_iov_schema_add_uint64(nvlist_t *schema, const char *name, uint32_t flags,
uint64_t defaultVal);
void
pci_iov_schema_add_unicast_mac(nvlist_t *schema, const char *name, uint32_t flags,
const uint8_t *defaultVal);
DESCRIPTION
The PCI Single-Root I/O Virtualization (SR-IOV) configuration schema is a data structure
that describes the device-specific configuration parameters that a PF driver will accept
when SR-IOV is enabled on the PF device. Each PF driver defines two schema instances: the
PF schema and the VF schema. The PF schema describes configuration that applies to the PF
device as a whole. The VF schema describes configuration that applies to an individual VF
device. Different VF devices may have different configuration applied to them, as long as
the configuration for each VF conforms to the VF schema.
A PF driver builds a configuration schema by first allocating a schema node and then adding
configuration parameter specifications to the schema. The configuration parameter
specification consists of a name and a value type.
Configuration parameter names are case-insensitive. It is an error to specify two or more
configuration parameters with the same name. It is also an error to specific a
configuration parameter that uses the same name as a configuration parameter used by the SR-
IOV infrastructure. See iovctl.conf(5) for documentation of all configuration parameters
used by the SR-IOV infrastructure.
The parameter type constrains the possible values that the configuration parameter may take.
A configuration parameter may be specified as a required parameter by setting the
IOV_SCHEMA_REQUIRED flag in the flags argument. Required parameters must be specified by
the user when SR-IOV is enabled. If the user does not specify a required parameter, the SR-
IOV infrastructure will abort the request to enable SR-IOV and return an error to the user.
Alternatively, a configuration parameter may be given a default value by setting the
IOV_SCHEMA_HASDEFAULT flag in the flags argument. If a configuration parameter has a
default value but the user has not specified a value for that parameter, then the SR-IOV
infrastructure will apply defaultVal for that parameter in the configuration before passing
it to the PF driver. It is an error for the value of the defaultVal parameter to not
conform to the restrictions of the specified type. If this flag is not specified then the
defaultVal argument is ignored. This flag is not compatible with the IOV_SCHEMA_REQUIRED
flag; it is an error to specify both on the same parameter.
The SR-IOV infrastructure guarantees that all configuration parameters that are either
specified as required or given a default value will be present in the configuration passed
to the PF driver. Configuration parameters that are neither specified as required nor given
a default value are optional and may or may not be present in the configuration passed to
the PF driver.
It is highly recommended that a PF driver reserve the use of optional parameters for
configuration that is truly optional. For example, a Network Interface PF device might have
the option to encapsulate all traffic to and from a VF device in a vlan tag. The PF driver
could expose that option as a "vlan" parameter accepting an integer argument specifying the
vlan tag. In this case, it would be appropriate to set the "vlan" parameter as an optional
parameter as it would be legitimate for a VF to be configured to have no vlan tagging
enabled at all.
Alternatively, if the PF device had an boolean option that controlled whether the VF was
allowed to change its MAC address, it would not be appropriate to set this parameter as
optional. The PF driver must either allow the MAC to change or not, so it would be more
appropriate for the PF driver to document the default behaviour by specifying a default
value in the schema (or potentially force the user to make the choice by setting the
parameter to be required).
Configuration parameters that have security implications must default to the most secure
configuration possible.
All device-specific configuration parameters must be documented in the manual page for the
PF driver, or in a separate manual page that is cross-referenced from the main driver manual
page.
It is not necessary for a PF driver to check for failure from any of these functions. If an
error occurs, it is flagged in the schema. The pci_iov_attach(9) function checks for this
error and will fail to initialize SR-IOV on the PF device if an error is set in the schema.
If this occurs, it is recommended that the PF driver still succeed in attaching and run with
SR-IOV disabled on the device.
The pci_iov_schema_alloc_node() function is used to allocate an empty configuration schema.
It is not necessary to check for failure from this function. The SR-IOV infrastructure will
gracefully handle failure to allocate a schema and will simply not enable SR-IOV on the PF
device.
The pci_iov_schema_add_bool() function is used to specify a configuration parameter in the
given schema with the name name and having a boolean type. Boolean values can only take the
value true or false (1 or 0, respectively).
The pci_iov_schema_add_string() function is used to specify a configuration parameter in the
given schema with the name name and having a string type. String values are standard C
strings.
The pci_iov_schema_add_uint8() function is used to specify a configuration parameter in the
given schema with the name name and having a uint8_t type. Values of type uint8_t are
unsigned integers in the range 0 to 255, inclusive.
The pci_iov_schema_add_uint16() function is used to specify a configuration parameter in the
given schema with the name name and having a uint16_t type. Values of type uint16_t are
unsigned integers in the range 0 to 65535, inclusive.
The pci_iov_schema_add_uint32() function is used to specify a configuration parameter in the
given schema with the name name and having a uint32_t type. Values of type uint32_t are
unsigned integers in the range 0 to (2**32 - 1), inclusive.
The pci_iov_schema_add_uint64() function is used to specify a configuration parameter in the
given schema with the name name and having a uint64_t type. Values of type uint64_t are
unsigned integers in the range 0 to (2**64 - 1), inclusive.
The pci_iov_schema_add_unicast_mac() function is used to specify a configuration parameter
in the given schema with the name name and having a unicast-mac type. Values of type
unicast-mac are binary values exactly 6 bytes long. The MAC address is guaranteed to not be
a multicast or broadcast address.
RETURN VALUES
The pci_iov_schema_alloc_node() function returns a pointer to the allocated schema, or NULL
if a failure occurs.
SEE ALSO
pci(9), PCI_IOV_ADD_VF(9), PCI_IOV_INIT(9)
AUTHORS
This manual page was written by Ryan Stone <rstone@FreeBSD.org>.