docs: documentation for xnvme ioengine

[fio.git] / HOWTO.rst

diff --git a/HOWTO.rst b/HOWTO.rst
index 6a3e09f51938788e4a272cc958a02d4e4c845558..84bea5c5ba0b0cf577aee9d6608dcad405f7af22 100644 (file)
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -2171,6 +2171,12 @@ I/O engine
                **exec**
                        Execute 3rd party tools. Could be used to perform monitoring during jobs runtime.
 
+               **xnvme**
+                       I/O engine using the xNVMe C API, for NVMe devices. The xnvme engine provides
+                       flexibility to access GNU/Linux Kernel NVMe driver via libaio, IOCTLs, io_uring,
+                       the SPDK NVMe driver, or your own custom NVMe driver. The xnvme engine includes
+                       engine specific options. (See https://xnvme.io).
+
 I/O engine specific parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -2260,7 +2266,7 @@ with the caveat that when used on the command line, they must come after the
        making the submission and completion part more lightweight. Required
        for the below :option:`sqthread_poll` option.
 
-.. option:: sqthread_poll : [io_uring]
+.. option:: sqthread_poll : [io_uring] [xnvme]
 
        Normally fio will submit IO by issuing a system call to notify the
        kernel of available items in the SQ ring. If this option is set, the
@@ -2275,7 +2281,7 @@ with the caveat that when used on the command line, they must come after the
 
 .. option:: hipri
 
-   [io_uring]
+   [io_uring], [xnvme]
 
         If this option is set, fio will attempt to use polled IO completions.
         Normal IO completions generate interrupts to signal the completion of
@@ -2725,6 +2731,51 @@ with the caveat that when used on the command line, they must come after the
 
        If set, stdout and stderr streams are redirected to files named from the job name. Default is true.
 
+.. option:: xnvme_async=str : [xnvme]
+
+       Select the xnvme async command interface. This can take these values.
+
+       **emu**
+               This is default and used to emulate asynchronous I/O.
+       **thrpool**
+               Use thread pool for Asynchronous I/O.
+       **io_uring**
+               Use Linux io_uring/liburing for Asynchronous I/O.
+       **libaio**
+               Use Linux aio for Asynchronous I/O.
+       **posix**
+               Use POSIX aio for Asynchronous I/O.
+       **nil**
+               Use nil-io; For introspective perf. evaluation
+
+.. option:: xnvme_sync=str : [xnvme]
+
+       Select the xnvme synchronous command interface. This can take these values.
+
+       **nvme**
+               This is default and uses Linux NVMe Driver ioctl() for synchronous I/O.
+       **psync**
+               Use pread()/write() for synchronous I/O.
+
+.. option:: xnvme_admin=str : [xnvme]
+
+       Select the xnvme admin command interface. This can take these values.
+
+       **nvme**
+               This is default and uses linux NVMe Driver ioctl() for admin commands.
+       **block**
+               Use Linux Block Layer ioctl() and sysfs for admin commands.
+       **file_as_ns**
+               Use file-stat to construct NVMe idfy responses.
+
+.. option:: xnvme_dev_nsid=int : [xnvme]
+
+       xnvme namespace identifier, for userspace NVMe driver.
+
+.. option:: xnvme_iovec=int : [xnvme]
+
+       If this option is set. xnvme will use vectored read/write commands.
+
 I/O depth
 ~~~~~~~~~