xref: /freebsd/share/man/man9/pci_iov_schema.9 (revision 0a36787e4c1fa0cf77dcf83be0867178476e372b)
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28.Dd July 8, 2015
29.Dt PCI_IOV_SCHEMA 9
30.Os
31.Sh NAME
32.Nm pci_iov_schema ,
33.Nm pci_iov_schema_alloc_node ,
34.Nm pci_iov_schema_add_bool ,
35.Nm pci_iov_schema_add_string ,
36.Nm pci_iov_schema_add_uint8 ,
37.Nm pci_iov_schema_add_uint16 ,
38.Nm pci_iov_schema_add_uint32 ,
39.Nm pci_iov_schema_add_uint64 ,
40.Nm pci_iov_schema_add_unicast_mac
41.Nd PCI SR-IOV config schema interface
42.Sh SYNOPSIS
43.In machine/stdarg.h
44.In sys/nv.h
45.In sys/iov_schema.h
46.Ft nvlist_t *
47.Fn pci_iov_schema_alloc_node "void"
48.Ft void
49.Fn pci_iov_schema_add_bool "nvlist_t *schema" "const char *name" \
50"uint32_t flags" "int defaultVal"
51.Ft void
52.Fn pci_iov_schema_add_string "nvlist_t *schema" "const char *name" \
53"uint32_t flags" "const char *defaultVal"
54.Ft void
55.Fn pci_iov_schema_add_uint8 "nvlist_t *schema" "const char *name" \
56"uint32_t flags" "uint8_t defaultVal"
57.Ft void
58.Fn pci_iov_schema_add_uint16 "nvlist_t *schema" "const char *name" \
59"uint32_t flags" "uint16_t defaultVal"
60.Ft void
61.Fn pci_iov_schema_add_uint32 "nvlist_t *schema" "const char *name" \
62"uint32_t flags" "uint32_t defaultVal"
63.Ft void
64.Fn pci_iov_schema_add_uint64 "nvlist_t *schema" "const char *name" \
65"uint32_t flags" "uint64_t defaultVal"
66.Ft void
67.Fn pci_iov_schema_add_unicast_mac "nvlist_t *schema" "const char *name" \
68"uint32_t flags" "const uint8_t *defaultVal"
69.Sh DESCRIPTION
70The PCI Single-Root I/O Virtualization
71.Pq SR-IOV
72configuration schema is a data
73structure that describes the device-specific configuration parameters that a PF
74driver will accept when SR-IOV is enabled on the PF device.
75Each PF driver defines two schema instances: the PF schema and the VF schema.
76The PF schema describes configuration that applies to the PF device as a whole.
77The VF schema describes configuration that applies to an individual VF device.
78Different VF devices may have different configuration applied to them, as long
79as the configuration for each VF conforms to the VF schema.
80.Pp
81A PF driver builds a configuration schema by first allocating a schema node and
82then adding configuration parameter specifications to the schema.
83The configuration parameter specification consists of a name and a value type.
84.Pp
85Configuration parameter names are case-insensitive.
86It is an error to specify two or more configuration parameters with the same
87name.
88It is also an error to specific a configuration parameter that uses the same
89name as a configuration parameter used by the SR-IOV infrastructure.
90See
91.Xr iovctl.conf 5
92for documentation of all configuration parameters used by the SR-IOV
93infrastructure.
94.Pp
95The parameter type constrains the possible values that the configuration
96parameter may take.
97.Pp
98A configuration parameter may be specified as a required parameter by setting
99the
100.Dv IOV_SCHEMA_REQUIRED
101flag in the
102.Pa flags
103argument.
104Required parameters must be specified by the user when SR-IOV is enabled.
105If the user does not specify a required parameter, the SR-IOV infrastructure
106will abort the request to enable SR-IOV and return an error to the user.
107.Pp
108Alternatively, a configuration parameter may be given a default value by
109setting the
110.Dv IOV_SCHEMA_HASDEFAULT
111flag in the
112.Pa flags
113argument.
114If a configuration parameter has a default value but the user has not specified
115a value for that parameter, then the SR-IOV infrastructure will apply
116.Pa defaultVal
117for that parameter in the configuration before passing it to the PF driver.
118It is an error for the value of the
119.Pa defaultVal
120parameter to not conform to the restrictions of the specified type.
121If this flag is not specified then the
122.Pa defaultVal
123argument is ignored.
124This flag is not compatible with the
125.Dv IOV_SCHEMA_REQUIRED
126flag; it is an error to specify both on the same parameter.
127.Pp
128The SR-IOV infrastructure guarantees that all configuration parameters that are
129either specified as required or given a default value will be present in the
130configuration passed to the PF driver.
131Configuration parameters that are neither specified as required nor given a
132default value are optional and may or may not be present in the configuration
133passed to the PF driver.
134.Pp
135It is highly recommended that a PF driver reserve the use of optional parameters
136for configuration that is truly optional.
137For example, a Network Interface PF device might have the option to encapsulate
138all traffic to and from a VF device in a vlan tag.
139The PF driver could expose that option as a "vlan" parameter accepting an
140integer argument specifying the vlan tag.
141In this case, it would be appropriate to set the "vlan" parameter as an optional
142parameter as it would be legitimate for a VF to be configured to have no vlan
143tagging enabled at all.
144.Pp
145Alternatively, if the PF device had an boolean option that controlled whether
146the VF was allowed to change its MAC address, it would not be appropriate to
147set this parameter as optional.
148The PF driver must either allow the MAC to change or not, so it would be more
149appropriate for the PF driver to document the default behaviour by specifying
150a default value in the schema
151.Po or potentially force the user to make the choice by setting the parameter
152to be required
153.Pc .
154.Pp
155Configuration parameters that have security implications must default to the
156most secure configuration possible.
157.Pp
158All device-specific configuration parameters must be documented in the manual
159page for the PF driver, or in a separate manual page that is cross-referenced
160from the main driver manual page.
161.Pp
162It is not necessary for a PF driver to check for failure from any of these
163functions.
164If an error occurs, it is flagged in the schema.
165The
166.Xr pci_iov_attach 9
167function checks for this error and will fail to initialize SR-IOV on the PF
168device if an error is set in the schema.
169If this occurs, it is recommended that the PF driver still succeed in attaching
170and run with SR-IOV disabled on the device.
171.Pp
172The
173.Fn pci_iov_schema_alloc_node
174function is used to allocate an empty configuration schema.
175It is not necessary to check for failure from this function.
176The SR-IOV infrastructure will gracefully handle failure to allocate a schema
177and will simply not enable SR-IOV on the PF device.
178.Pp
179The
180.Fn pci_iov_schema_add_bool
181function is used to specify a configuration parameter in the given schema with
182the name
183.Pa name
184and having a boolean type.
185Boolean values can only take the value true or false (1 or 0, respectively).
186.Pp
187The
188.Fn pci_iov_schema_add_string
189function is used to specify a configuration parameter in the given schema with
190the name
191.Pa name
192and having a string type.
193String values are standard C strings.
194.Pp
195The
196.Fn pci_iov_schema_add_uint8
197function is used to specify a configuration parameter in the given schema with
198the name
199.Pa name
200and having a
201.Vt uint8_t
202type.
203Values of type
204.Vt uint8_t
205are unsigned integers in the range 0 to 255, inclusive.
206.Pp
207The
208.Fn pci_iov_schema_add_uint16
209function is used to specify a configuration parameter in the given schema with
210the name
211.Pa name
212and having a
213.Vt uint16_t
214type.
215Values of type
216.Vt uint16_t
217are unsigned integers in the range 0 to 65535, inclusive.
218.Pp
219The
220.Fn pci_iov_schema_add_uint32
221function is used to specify a configuration parameter in the given schema with
222the name
223.Pa name
224and having a
225.Vt uint32_t
226type.
227Values of type
228.Vt uint32_t
229are unsigned integers in the range 0 to
230.Pq 2**32 - 1 ,
231inclusive.
232.Pp
233The
234.Fn pci_iov_schema_add_uint64
235function is used to specify a configuration parameter in the given schema with
236the name
237.Pa name
238and having a
239.Vt uint64_t
240type.
241Values of type
242.Vt uint64_t
243are unsigned integers in the range 0 to
244.Pq 2**64 - 1 ,
245inclusive.
246.Pp
247The
248.Fn pci_iov_schema_add_unicast_mac
249function is used to specify a configuration parameter in the given schema with
250the name
251.Pa name
252and having a unicast-mac type.
253Values of type unicast-mac are binary values exactly 6 bytes long.
254The MAC address is guaranteed to not be a multicast or broadcast address.
255.Sh RETURN VALUES
256The
257.Fn pci_iov_schema_alloc_node
258function returns a pointer to the allocated schema, or NULL if a failure occurs.
259.Sh SEE ALSO
260.Xr pci 9 ,
261.Xr PCI_IOV_ADD_VF 9 ,
262.Xr PCI_IOV_INIT 9
263.Sh AUTHORS
264This manual page was written by
265.An Ryan Stone Aq rstone@FreeBSD.org .
266