direct-io.hg

changeset 15520:73290f6fe70a

Xen API specification improvements.

Move the error list to be more prominent, and explicitly document
which generic error codes can be returned by all methods.

Mark host CPU flags/features return value as unspecified.

Document PERMISSION_DENIED.

Document error returns of session.login_with_password.

Signed-off-by: John Levon <john.levon@sun.com>
author kfraser@localhost.localdomain
date Tue Jul 10 10:22:41 2007 +0100 (2007-07-10)
parents 80099a459d7a
children 1f348e70a5af
files docs/xen-api/xenapi-datamodel.tex
line diff
     1.1 --- a/docs/xen-api/xenapi-datamodel.tex	Tue Jul 10 10:15:01 2007 +0100
     1.2 +++ b/docs/xen-api/xenapi-datamodel.tex	Tue Jul 10 10:22:41 2007 +0100
     1.3 @@ -225,6 +225,249 @@ The following enumeration types are used
     1.4  \end{longtable}
     1.5  
     1.6  \vspace{1cm}
     1.7 +\newpage
     1.8 +\section{Error Handling}
     1.9 +When a low-level transport error occurs, or a request is malformed at the HTTP
    1.10 +or XML-RPC level, the server may send an XML-RPC Fault response, or the client
    1.11 +may simulate the same.  The client must be prepared to handle these errors,
    1.12 +though they may be treated as fatal.  On the wire, these are transmitted in a
    1.13 +form similar to this:
    1.14 +
    1.15 +\begin{verbatim}
    1.16 +    <methodResponse>
    1.17 +      <fault>
    1.18 +        <value>
    1.19 +          <struct>
    1.20 +            <member>
    1.21 +                <name>faultCode</name>
    1.22 +                <value><int>-1</int></value>
    1.23 +              </member>
    1.24 +              <member>
    1.25 +                <name>faultString</name>
    1.26 +                <value><string>Malformed request</string></value>
    1.27 +            </member>
    1.28 +          </struct>
    1.29 +        </value>
    1.30 +      </fault>
    1.31 +    </methodResponse>
    1.32 +\end{verbatim}
    1.33 +
    1.34 +All other failures are reported with a more structured error response, to
    1.35 +allow better automatic response to failures, proper internationalisation of
    1.36 +any error message, and easier debugging.  On the wire, these are transmitted
    1.37 +like this:
    1.38 +
    1.39 +\begin{verbatim}
    1.40 +    <struct>
    1.41 +      <member>
    1.42 +        <name>Status</name>
    1.43 +        <value>Failure</value>
    1.44 +      </member>
    1.45 +      <member>
    1.46 +        <name>ErrorDescription</name>
    1.47 +        <value>
    1.48 +          <array>
    1.49 +            <data>
    1.50 +              <value>MAP_DUPLICATE_KEY</value>
    1.51 +              <value>Customer</value>
    1.52 +              <value>eSpeil Inc.</value>
    1.53 +              <value>eSpeil Incorporated</value>
    1.54 +            </data>
    1.55 +          </array>
    1.56 +        </value>
    1.57 +      </member>
    1.58 +    </struct>
    1.59 +\end{verbatim}
    1.60 +
    1.61 +Note that {\tt ErrorDescription} value is an array of string values. The
    1.62 +first element of the array is an error code; the remainder of the array are
    1.63 +strings representing error parameters relating to that code.  In this case,
    1.64 +the client has attempted to add the mapping {\tt Customer $\rightarrow$
    1.65 +eSpiel Incorporated} to a Map, but it already contains the mapping
    1.66 +{\tt Customer $\rightarrow$ eSpiel Inc.}, and so the request has failed.
    1.67 +
    1.68 +The reference below lists each possible error returned by each method.
    1.69 +As well as the errors explicitly listed, any method may return low-level
    1.70 +errors as described above, or any of the following generic errors:
    1.71 +
    1.72 +\begin{itemize}
    1.73 +\item HANDLE\_INVALID
    1.74 +\item INTERNAL\_ERROR
    1.75 +\item MAP\_DUPLICATE\_KEY
    1.76 +\item MESSAGE\_METHOD\_UNKNOWN
    1.77 +\item MESSAGE\_PARAMETER\_COUNT\_MISMATCH
    1.78 +\item OPERATION\_NOT\_ALLOWED
    1.79 +\item PERMISSION\_DENIED
    1.80 +\item SESSION\_INVALID
    1.81 +\end{itemize}
    1.82 +
    1.83 +Each possible error code is documented in the following section.
    1.84 +
    1.85 +\subsection{Error Codes}
    1.86 +
    1.87 +\subsubsection{HANDLE\_INVALID}
    1.88 +
    1.89 +You gave an invalid handle.  The object may have recently been deleted. 
    1.90 +The class parameter gives the type of reference given, and the handle
    1.91 +parameter echoes the bad value given.
    1.92 +
    1.93 +\vspace{0.3cm}
    1.94 +{\bf Signature:}
    1.95 +\begin{verbatim}HANDLE_INVALID(class, handle)\end{verbatim}
    1.96 +\begin{center}\rule{10em}{0.1pt}\end{center}
    1.97 +
    1.98 +\subsubsection{INTERNAL\_ERROR}
    1.99 +
   1.100 +The server failed to handle your request, due to an internal error.  The
   1.101 +given message may give details useful for debugging the problem.
   1.102 +
   1.103 +\vspace{0.3cm}
   1.104 +{\bf Signature:}
   1.105 +\begin{verbatim}INTERNAL_ERROR(message)\end{verbatim}
   1.106 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.107 +
   1.108 +\subsubsection{MAP\_DUPLICATE\_KEY}
   1.109 +
   1.110 +You tried to add a key-value pair to a map, but that key is already there. 
   1.111 +The key, current value, and the new value that you tried to set are all
   1.112 +echoed.
   1.113 +
   1.114 +\vspace{0.3cm}
   1.115 +{\bf Signature:}
   1.116 +\begin{verbatim}MAP_DUPLICATE_KEY(key, current value, new value)\end{verbatim}
   1.117 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.118 +
   1.119 +\subsubsection{MESSAGE\_METHOD\_UNKNOWN}
   1.120 +
   1.121 +You tried to call a method that does not exist.  The method name that you
   1.122 +used is echoed.
   1.123 +
   1.124 +\vspace{0.3cm}
   1.125 +{\bf Signature:}
   1.126 +\begin{verbatim}MESSAGE_METHOD_UNKNOWN(method)\end{verbatim}
   1.127 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.128 +
   1.129 +\subsubsection{MESSAGE\_PARAMETER\_COUNT\_MISMATCH}
   1.130 +
   1.131 +You tried to call a method with the incorrect number of parameters.  The
   1.132 +fully-qualified method name that you used, and the number of received and
   1.133 +expected parameters are returned.
   1.134 +
   1.135 +\vspace{0.3cm}
   1.136 +{\bf Signature:}
   1.137 +\begin{verbatim}MESSAGE_PARAMETER_COUNT_MISMATCH(method, expected, received)\end{verbatim}
   1.138 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.139 +
   1.140 +\subsubsection{NETWORK\_ALREADY\_CONNECTED}
   1.141 +
   1.142 +You tried to create a PIF, but the network you tried to attach it to is
   1.143 +already attached to some other PIF, and so the creation failed.
   1.144 +
   1.145 +\vspace{0.3cm}
   1.146 +{\bf Signature:}
   1.147 +\begin{verbatim}NETWORK_ALREADY_CONNECTED(network, connected PIF)\end{verbatim}
   1.148 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.149 +
   1.150 +\subsubsection{OPERATION\_NOT\_ALLOWED}
   1.151 +
   1.152 +You attempted an operation that was not allowed.
   1.153 +
   1.154 +\vspace{0.3cm}
   1.155 +No parameters.
   1.156 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.157 +
   1.158 +\subsubsection{PERMISSION\_DENIED}
   1.159 +
   1.160 +You do not have the required permissions to perform the operation.
   1.161 +
   1.162 +\vspace{0.3cm}
   1.163 +No parameters.
   1.164 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.165 +
   1.166 +\subsubsection{PIF\_IS\_PHYSICAL}
   1.167 +
   1.168 +You tried to destroy a PIF, but it represents an aspect of the physical
   1.169 +host configuration, and so cannot be destroyed.  The parameter echoes the
   1.170 +PIF handle you gave.
   1.171 +
   1.172 +\vspace{0.3cm}
   1.173 +{\bf Signature:}
   1.174 +\begin{verbatim}PIF_IS_PHYSICAL(PIF)\end{verbatim}
   1.175 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.176 +
   1.177 +\subsubsection{SESSION\_AUTHENTICATION\_FAILED}
   1.178 +
   1.179 +The credentials given by the user are incorrect, so access has been denied,
   1.180 +and you have not been issued a session handle.
   1.181 +
   1.182 +\vspace{0.3cm}
   1.183 +No parameters.
   1.184 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.185 +
   1.186 +\subsubsection{SESSION\_INVALID}
   1.187 +
   1.188 +You gave an invalid session handle.  It may have been invalidated by a
   1.189 +server restart, or timed out.  You should get a new session handle, using
   1.190 +one of the session.login\_ calls.  This error does not invalidate the
   1.191 +current connection.  The handle parameter echoes the bad value given.
   1.192 +
   1.193 +\vspace{0.3cm}
   1.194 +{\bf Signature:}
   1.195 +\begin{verbatim}SESSION_INVALID(handle)\end{verbatim}
   1.196 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.197 +
   1.198 +\subsubsection{SESSION\_NOT\_REGISTERED}
   1.199 +
   1.200 +This session is not registered to receive events.  You must call
   1.201 +event.register before event.next.  The session handle you are using is
   1.202 +echoed.
   1.203 +
   1.204 +\vspace{0.3cm}
   1.205 +{\bf Signature:}
   1.206 +\begin{verbatim}SESSION_NOT_REGISTERED(handle)\end{verbatim}
   1.207 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.208 +
   1.209 +\subsubsection{VALUE\_NOT\_SUPPORTED}
   1.210 +
   1.211 +You attempted to set a value that is not supported by this implementation. 
   1.212 +The fully-qualified field name and the value that you tried to set are
   1.213 +returned.  Also returned is a developer-only diagnostic reason.
   1.214 +
   1.215 +\vspace{0.3cm}
   1.216 +{\bf Signature:}
   1.217 +\begin{verbatim}VALUE_NOT_SUPPORTED(field, value, reason)\end{verbatim}
   1.218 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.219 +
   1.220 +\subsubsection{VLAN\_TAG\_INVALID}
   1.221 +
   1.222 +You tried to create a VLAN, but the tag you gave was invalid -- it mmust be
   1.223 +between 0 and 4095.  The parameter echoes the VLAN tag you gave.
   1.224 +
   1.225 +\vspace{0.3cm}
   1.226 +{\bf Signature:}
   1.227 +\begin{verbatim}VLAN_TAG_INVALID(VLAN)\end{verbatim}
   1.228 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.229 +
   1.230 +\subsubsection{VM\_BAD\_POWER\_STATE}
   1.231 +
   1.232 +You attempted an operation on a VM that was not in an appropriate power
   1.233 +state at the time; for example, you attempted to start a VM that was
   1.234 +already running.  The parameters returned are the VM's handle, and the
   1.235 +expected and actual VM state at the time of the call.
   1.236 +
   1.237 +\vspace{0.3cm}
   1.238 +{\bf Signature:}
   1.239 +\begin{verbatim}VM_BAD_POWER_STATE(vm, expected, actual)\end{verbatim}
   1.240 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.241 +
   1.242 +\subsubsection{VM\_HVM\_REQUIRED}
   1.243 +
   1.244 +HVM is required for this operation
   1.245 +
   1.246 +\vspace{0.3cm}
   1.247 +{\bf Signature:}
   1.248 +\begin{verbatim}VM_HVM_REQUIRED(vm)\end{verbatim}
   1.249 +\begin{center}\rule{10em}{0.1pt}\end{center}
   1.250  
   1.251  \newpage
   1.252  \section{Class: session}
   1.253 @@ -275,6 +518,11 @@ session ref
   1.254  
   1.255  
   1.256  ID of newly created session
   1.257 +
   1.258 +\vspace{0.3cm}
   1.259 +
   1.260 +\noindent{\bf Possible Error Codes:} {\tt SESSION\_AUTHENTICATION\_FAILED}
   1.261 +
   1.262  \vspace{0.3cm}
   1.263  \vspace{0.3cm}
   1.264  \vspace{0.3cm}
   1.265 @@ -7100,7 +7348,9 @@ value of the field
   1.266  \subsubsection{RPC name:~get\_flags}
   1.267  
   1.268  {\bf Overview:} 
   1.269 -Get the flags field of the given host\_cpu.
   1.270 +Get the flags field of the given host\_cpu.  As of this version of the
   1.271 +API, the semantics of the returned string are explicitly unspecified,
   1.272 +and may change in the future.
   1.273  
   1.274   \noindent {\bf Signature:} 
   1.275  \begin{verbatim} string get_flags (session_id s, host_cpu ref self)\end{verbatim}
   1.276 @@ -7132,7 +7382,9 @@ value of the field
   1.277  \subsubsection{RPC name:~get\_features}
   1.278  
   1.279  {\bf Overview:} 
   1.280 -Get the features field of the given host\_cpu.
   1.281 +Get the features field of the given host\_cpu. As of this version of the
   1.282 +API, the semantics of the returned string are explicitly unspecified,
   1.283 +and may change in the future.
   1.284  
   1.285   \noindent {\bf Signature:} 
   1.286  \begin{verbatim} string get_features (session_id s, host_cpu ref self)\end{verbatim}
   1.287 @@ -14192,224 +14444,3 @@ all fields from the object
   1.288  \vspace{0.3cm}
   1.289  \vspace{0.3cm}
   1.290  
   1.291 -\vspace{1cm}
   1.292 -\newpage
   1.293 -\section{Error Handling}
   1.294 -When a low-level transport error occurs, or a request is malformed at the HTTP
   1.295 -or XML-RPC level, the server may send an XML-RPC Fault response, or the client
   1.296 -may simulate the same.  The client must be prepared to handle these errors,
   1.297 -though they may be treated as fatal.  On the wire, these are transmitted in a
   1.298 -form similar to this:
   1.299 -
   1.300 -\begin{verbatim}
   1.301 -    <methodResponse>
   1.302 -      <fault>
   1.303 -        <value>
   1.304 -          <struct>
   1.305 -            <member>
   1.306 -                <name>faultCode</name>
   1.307 -                <value><int>-1</int></value>
   1.308 -              </member>
   1.309 -              <member>
   1.310 -                <name>faultString</name>
   1.311 -                <value><string>Malformed request</string></value>
   1.312 -            </member>
   1.313 -          </struct>
   1.314 -        </value>
   1.315 -      </fault>
   1.316 -    </methodResponse>
   1.317 -\end{verbatim}
   1.318 -
   1.319 -All other failures are reported with a more structured error response, to
   1.320 -allow better automatic response to failures, proper internationalisation of
   1.321 -any error message, and easier debugging.  On the wire, these are transmitted
   1.322 -like this:
   1.323 -
   1.324 -\begin{verbatim}
   1.325 -    <struct>
   1.326 -      <member>
   1.327 -        <name>Status</name>
   1.328 -        <value>Failure</value>
   1.329 -      </member>
   1.330 -      <member>
   1.331 -        <name>ErrorDescription</name>
   1.332 -        <value>
   1.333 -          <array>
   1.334 -            <data>
   1.335 -              <value>MAP_DUPLICATE_KEY</value>
   1.336 -              <value>Customer</value>
   1.337 -              <value>eSpeil Inc.</value>
   1.338 -              <value>eSpeil Incorporated</value>
   1.339 -            </data>
   1.340 -          </array>
   1.341 -        </value>
   1.342 -      </member>
   1.343 -    </struct>
   1.344 -\end{verbatim}
   1.345 -
   1.346 -Note that {\tt ErrorDescription} value is an array of string values. The
   1.347 -first element of the array is an error code; the remainder of the array are
   1.348 -strings representing error parameters relating to that code.  In this case,
   1.349 -the client has attempted to add the mapping {\tt Customer $\rightarrow$
   1.350 -eSpiel Incorporated} to a Map, but it already contains the mapping
   1.351 -{\tt Customer $\rightarrow$ eSpiel Inc.}, and so the request has failed.
   1.352 -
   1.353 -Each possible error code is documented in the following section.
   1.354 -
   1.355 -\subsection{Error Codes}
   1.356 -
   1.357 -\subsubsection{HANDLE\_INVALID}
   1.358 -
   1.359 -You gave an invalid handle.  The object may have recently been deleted. 
   1.360 -The class parameter gives the type of reference given, and the handle
   1.361 -parameter echoes the bad value given.
   1.362 -
   1.363 -\vspace{0.3cm}
   1.364 -{\bf Signature:}
   1.365 -\begin{verbatim}HANDLE_INVALID(class, handle)\end{verbatim}
   1.366 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.367 -
   1.368 -\subsubsection{INTERNAL\_ERROR}
   1.369 -
   1.370 -The server failed to handle your request, due to an internal error.  The
   1.371 -given message may give details useful for debugging the problem.
   1.372 -
   1.373 -\vspace{0.3cm}
   1.374 -{\bf Signature:}
   1.375 -\begin{verbatim}INTERNAL_ERROR(message)\end{verbatim}
   1.376 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.377 -
   1.378 -\subsubsection{MAP\_DUPLICATE\_KEY}
   1.379 -
   1.380 -You tried to add a key-value pair to a map, but that key is already there. 
   1.381 -The key, current value, and the new value that you tried to set are all
   1.382 -echoed.
   1.383 -
   1.384 -\vspace{0.3cm}
   1.385 -{\bf Signature:}
   1.386 -\begin{verbatim}MAP_DUPLICATE_KEY(key, current value, new value)\end{verbatim}
   1.387 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.388 -
   1.389 -\subsubsection{MESSAGE\_METHOD\_UNKNOWN}
   1.390 -
   1.391 -You tried to call a method that does not exist.  The method name that you
   1.392 -used is echoed.
   1.393 -
   1.394 -\vspace{0.3cm}
   1.395 -{\bf Signature:}
   1.396 -\begin{verbatim}MESSAGE_METHOD_UNKNOWN(method)\end{verbatim}
   1.397 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.398 -
   1.399 -\subsubsection{MESSAGE\_PARAMETER\_COUNT\_MISMATCH}
   1.400 -
   1.401 -You tried to call a method with the incorrect number of parameters.  The
   1.402 -fully-qualified method name that you used, and the number of received and
   1.403 -expected parameters are returned.
   1.404 -
   1.405 -\vspace{0.3cm}
   1.406 -{\bf Signature:}
   1.407 -\begin{verbatim}MESSAGE_PARAMETER_COUNT_MISMATCH(method, expected, received)\end{verbatim}
   1.408 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.409 -
   1.410 -\subsubsection{NETWORK\_ALREADY\_CONNECTED}
   1.411 -
   1.412 -You tried to create a PIF, but the network you tried to attach it to is
   1.413 -already attached to some other PIF, and so the creation failed.
   1.414 -
   1.415 -\vspace{0.3cm}
   1.416 -{\bf Signature:}
   1.417 -\begin{verbatim}NETWORK_ALREADY_CONNECTED(network, connected PIF)\end{verbatim}
   1.418 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.419 -
   1.420 -\subsubsection{OPERATION\_NOT\_ALLOWED}
   1.421 -
   1.422 -You attempted an operation that was not allowed.
   1.423 -
   1.424 -\vspace{0.3cm}
   1.425 -No parameters.
   1.426 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.427 -
   1.428 -\subsubsection{PIF\_IS\_PHYSICAL}
   1.429 -
   1.430 -You tried to destroy a PIF, but it represents an aspect of the physical
   1.431 -host configuration, and so cannot be destroyed.  The parameter echoes the
   1.432 -PIF handle you gave.
   1.433 -
   1.434 -\vspace{0.3cm}
   1.435 -{\bf Signature:}
   1.436 -\begin{verbatim}PIF_IS_PHYSICAL(PIF)\end{verbatim}
   1.437 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.438 -
   1.439 -\subsubsection{SESSION\_AUTHENTICATION\_FAILED}
   1.440 -
   1.441 -The credentials given by the user are incorrect, so access has been denied,
   1.442 -and you have not been issued a session handle.
   1.443 -
   1.444 -\vspace{0.3cm}
   1.445 -No parameters.
   1.446 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.447 -
   1.448 -\subsubsection{SESSION\_INVALID}
   1.449 -
   1.450 -You gave an invalid session handle.  It may have been invalidated by a
   1.451 -server restart, or timed out.  You should get a new session handle, using
   1.452 -one of the session.login\_ calls.  This error does not invalidate the
   1.453 -current connection.  The handle parameter echoes the bad value given.
   1.454 -
   1.455 -\vspace{0.3cm}
   1.456 -{\bf Signature:}
   1.457 -\begin{verbatim}SESSION_INVALID(handle)\end{verbatim}
   1.458 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.459 -
   1.460 -\subsubsection{SESSION\_NOT\_REGISTERED}
   1.461 -
   1.462 -This session is not registered to receive events.  You must call
   1.463 -event.register before event.next.  The session handle you are using is
   1.464 -echoed.
   1.465 -
   1.466 -\vspace{0.3cm}
   1.467 -{\bf Signature:}
   1.468 -\begin{verbatim}SESSION_NOT_REGISTERED(handle)\end{verbatim}
   1.469 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.470 -
   1.471 -\subsubsection{VALUE\_NOT\_SUPPORTED}
   1.472 -
   1.473 -You attempted to set a value that is not supported by this implementation. 
   1.474 -The fully-qualified field name and the value that you tried to set are
   1.475 -returned.  Also returned is a developer-only diagnostic reason.
   1.476 -
   1.477 -\vspace{0.3cm}
   1.478 -{\bf Signature:}
   1.479 -\begin{verbatim}VALUE_NOT_SUPPORTED(field, value, reason)\end{verbatim}
   1.480 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.481 -
   1.482 -\subsubsection{VLAN\_TAG\_INVALID}
   1.483 -
   1.484 -You tried to create a VLAN, but the tag you gave was invalid -- it mmust be
   1.485 -between 0 and 4095.  The parameter echoes the VLAN tag you gave.
   1.486 -
   1.487 -\vspace{0.3cm}
   1.488 -{\bf Signature:}
   1.489 -\begin{verbatim}VLAN_TAG_INVALID(VLAN)\end{verbatim}
   1.490 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.491 -
   1.492 -\subsubsection{VM\_BAD\_POWER\_STATE}
   1.493 -
   1.494 -You attempted an operation on a VM that was not in an appropriate power
   1.495 -state at the time; for example, you attempted to start a VM that was
   1.496 -already running.  The parameters returned are the VM's handle, and the
   1.497 -expected and actual VM state at the time of the call.
   1.498 -
   1.499 -\vspace{0.3cm}
   1.500 -{\bf Signature:}
   1.501 -\begin{verbatim}VM_BAD_POWER_STATE(vm, expected, actual)\end{verbatim}
   1.502 -\begin{center}\rule{10em}{0.1pt}\end{center}
   1.503 -
   1.504 -\subsubsection{VM\_HVM\_REQUIRED}
   1.505 -
   1.506 -HVM is required for this operation
   1.507 -
   1.508 -\vspace{0.3cm}
   1.509 -{\bf Signature:}
   1.510 -\begin{verbatim}VM_HVM_REQUIRED(vm)\end{verbatim}
   1.511 -\begin{center}\rule{10em}{0.1pt}\end{center}