QTest Device Emulation Testing Framework¶
QTest is a device emulation testing framework. It can be very useful to test device models; it could also control certain aspects of QEMU (such as virtual clock stepping), with a special purpose “qtest” protocol. Refer to QTest Protocol for more details of the protocol.
QTest cases can be executed with
make check-qtest
The QTest library is implemented by tests/qtest/libqtest.c
and the API is
defined in tests/qtest/libqtest.h
.
Consider adding a new QTest case when you are introducing a new virtual hardware, or extending one if you are adding functionalities to an existing virtual device.
On top of libqtest, a higher level library, libqos
, was created to
encapsulate common tasks of device drivers, such as memory management and
communicating with system buses or devices. Many virtual device tests use
libqos instead of directly calling into libqtest.
Steps to add a new QTest case are:
Create a new source file for the test. (More than one file can be added as necessary.) For example,
tests/qtest/foo-test.c
.Write the test code with the glib and libqtest/libqos API. See also existing tests and the library headers for reference.
Register the new test in
tests/qtest/meson.build
. Add the test executable name to an appropriateqtests_*
variable. There is one variable per architecture, plusqtests_generic
for tests that can be run for all architectures. For example:qtests_generic = [ ... 'foo-test', ... ]
If the test has more than one source file or needs to be linked with any dependency other than
qemuutil
andqos
, list them in theqtests
dictionary. For example a test that needs to use theQIO
library will have an entry like:{ ... 'foo-test': [io], ... }
Debugging a QTest failure is slightly harder than the unit test because the
tests look up QEMU program names in the environment variables, such as
QTEST_QEMU_BINARY
and QTEST_QEMU_IMG
, and also because it is not easy
to attach gdb to the QEMU process spawned from the test. But manual invoking
and using gdb on the test is still simple to do: find out the actual command
from the output of
make check-qtest V=1
which you can run manually.
QTest Protocol¶
Line based protocol, request/response based. Server can send async messages so clients should always handle many async messages before the response comes in.
Valid requests¶
Clock management:¶
The qtest client is completely in charge of the QEMU_CLOCK_VIRTUAL. qtest commands let you adjust the value of the clock (monotonically). All the commands return the current value of the clock in nanoseconds.
> clock_step
< OK VALUE
Advance the clock to the next deadline. Useful when waiting for asynchronous events.
> clock_step NS
< OK VALUE
Advance the clock by NS nanoseconds.
> clock_set NS
< OK VALUE
Advance the clock to NS nanoseconds (do nothing if it’s already past).
PIO and memory access:¶
> outb ADDR VALUE
< OK
> outw ADDR VALUE
< OK
> outl ADDR VALUE
< OK
> inb ADDR
< OK VALUE
> inw ADDR
< OK VALUE
> inl ADDR
< OK VALUE
> writeb ADDR VALUE
< OK
> writew ADDR VALUE
< OK
> writel ADDR VALUE
< OK
> writeq ADDR VALUE
< OK
> readb ADDR
< OK VALUE
> readw ADDR
< OK VALUE
> readl ADDR
< OK VALUE
> readq ADDR
< OK VALUE
> read ADDR SIZE
< OK DATA
> write ADDR SIZE DATA
< OK
> b64read ADDR SIZE
< OK B64_DATA
> b64write ADDR SIZE B64_DATA
< OK
> memset ADDR SIZE VALUE
< OK
ADDR, SIZE, VALUE are all integers parsed with strtoul() with a base of 0. For ‘memset’ a zero size is permitted and does nothing.
DATA is an arbitrarily long hex number prefixed with ‘0x’. If it’s smaller than the expected size, the value will be zero filled at the end of the data sequence.
B64_DATA is an arbitrarily long base64 encoded string. If the sizes do not match, the data will be truncated.
IRQ management:¶
> irq_intercept_in QOM-PATH
< OK
> irq_intercept_out QOM-PATH
< OK
Attach to the gpio-in (resp. gpio-out) pins exported by the device at QOM-PATH. When the pin is triggered, one of the following async messages will be printed to the qtest stream:
IRQ raise NUM
IRQ lower NUM
where NUM is an IRQ number. For the PC, interrupts can be intercepted simply with “irq_intercept_in ioapic” (note that IRQ0 comes out with NUM=0 even though it is remapped to GSI 2).
Setting interrupt level:¶
> set_irq_in QOM-PATH NAME NUM LEVEL
< OK
where NAME is the name of the irq/gpio list, NUM is an IRQ number and LEVEL is an signed integer IRQ level.
Forcibly set the given interrupt pin to the given level.
libqtest API reference¶
-
QTestState *
qtest_initf
(const char *fmt, ...)¶
Parameters
const char * fmt
Format for creating other arguments to pass to QEMU, formatted like sprintf().
...
variable arguments
Description
Convenience wrapper around qtest_init().
Return
QTestState
instance.
-
QTestState *
qtest_vinitf
(const char *fmt, va_list ap)¶
Parameters
const char * fmt
Format for creating other arguments to pass to QEMU, formatted like vsprintf().
va_list ap
Format arguments.
Description
Convenience wrapper around qtest_init().
Return
QTestState
instance.
-
QTestState *
qtest_init
(const char *extra_args)¶
Parameters
const char * extra_args
other arguments to pass to QEMU. CAUTION: these arguments are subject to word splitting and shell evaluation.
Return
QTestState
instance.
-
QTestState *
qtest_init_without_qmp_handshake
(const char *extra_args)¶
Parameters
const char * extra_args
other arguments to pass to QEMU. CAUTION: these arguments are subject to word splitting and shell evaluation.
Return
QTestState
instance.
-
QTestState *
qtest_init_with_serial
(const char *extra_args, int *sock_fd)¶
Parameters
const char * extra_args
other arguments to pass to QEMU. CAUTION: these arguments are subject to word splitting and shell evaluation.
int * sock_fd
pointer to store the socket file descriptor for connection with serial.
Return
QTestState
instance.
-
void
qtest_quit
(QTestState *s)¶
Parameters
QTestState * s
QTestState
instance to operate on.
Description
Shut down the QEMU process associated to s.
-
QDict *
qtest_qmp_fds
(QTestState *s, int *fds, size_t fds_num, const char *fmt, ...)¶
Parameters
QTestState * s
QTestState
instance to operate on.int * fds
array of file descriptors
size_t fds_num
number of elements in fds
const char * fmt
QMP message to send to qemu, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
...
variable arguments
Description
Sends a QMP message to QEMU with fds and returns the response.
-
QDict *
qtest_qmp
(QTestState *s, const char *fmt, ...)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * fmt
QMP message to send to qemu, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
...
variable arguments
Description
Sends a QMP message to QEMU and returns the response.
-
void
qtest_qmp_send
(QTestState *s, const char *fmt, ...)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * fmt
QMP message to send to qemu, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
...
variable arguments
Description
Sends a QMP message to QEMU and leaves the response in the stream.
-
void
qtest_qmp_send_raw
(QTestState *s, const char *fmt, ...)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * fmt
text to send, formatted like sprintf()
...
variable arguments
Description
Sends text to the QMP monitor verbatim. Need not be valid JSON; this is useful for negative tests.
-
QDict *
qtest_vqmp_fds
(QTestState *s, int *fds, size_t fds_num, const char *fmt, va_list ap)¶
Parameters
QTestState * s
QTestState
instance to operate on.int * fds
array of file descriptors
size_t fds_num
number of elements in fds
const char * fmt
QMP message to send to QEMU, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
va_list ap
QMP message arguments
Description
Sends a QMP message to QEMU with fds and returns the response.
-
QDict *
qtest_vqmp
(QTestState *s, const char *fmt, va_list ap)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * fmt
QMP message to send to QEMU, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
va_list ap
QMP message arguments
Description
Sends a QMP message to QEMU and returns the response.
-
void
qtest_qmp_vsend_fds
(QTestState *s, int *fds, size_t fds_num, const char *fmt, va_list ap)¶
Parameters
QTestState * s
QTestState
instance to operate on.int * fds
array of file descriptors
size_t fds_num
number of elements in fds
const char * fmt
QMP message to send to QEMU, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
va_list ap
QMP message arguments
Description
Sends a QMP message to QEMU and leaves the response in the stream.
-
void
qtest_qmp_vsend
(QTestState *s, const char *fmt, va_list ap)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * fmt
QMP message to send to QEMU, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
va_list ap
QMP message arguments
Description
Sends a QMP message to QEMU and leaves the response in the stream.
-
QDict *
qtest_qmp_receive_dict
(QTestState *s)¶
Parameters
QTestState * s
QTestState
instance to operate on.
Description
Reads a QMP message from QEMU and returns the response.
-
QDict *
qtest_qmp_receive
(QTestState *s)¶
Parameters
QTestState * s
QTestState
instance to operate on.
Description
Reads a QMP message from QEMU and returns the response. Buffers all the events received meanwhile, until a call to qtest_qmp_eventwait
-
void
qtest_qmp_eventwait
(QTestState *s, const char *event)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * event
event to wait for.
Description
Continuously polls for QMP responses until it receives the desired event.
-
QDict *
qtest_qmp_eventwait_ref
(QTestState *s, const char *event)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * event
event to wait for.
Description
Continuously polls for QMP responses until it receives the desired event. Returns a copy of the event for further investigation.
-
QDict *
qtest_qmp_event_ref
(QTestState *s, const char *event)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * event
event to return.
Description
Removes non-matching events from the buffer that was set by qtest_qmp_receive, until an event bearing the given name is found, and returns it. If no event matches, clears the buffer and returns NULL.
-
char *
qtest_hmp
(QTestState *s, const char *fmt, ...)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * fmt
HMP command to send to QEMU, formats arguments like sprintf().
...
variable arguments
Description
Send HMP command to QEMU via QMP’s human-monitor-command. QMP events are discarded.
Return
the command’s output. The caller should g_free() it.
-
char *
qtest_vhmp
(QTestState *s, const char *fmt, va_list ap)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * fmt
HMP command to send to QEMU, formats arguments like vsprintf().
va_list ap
HMP command arguments
Description
Send HMP command to QEMU via QMP’s human-monitor-command. QMP events are discarded.
Return
the command’s output. The caller should g_free() it.
-
bool
qtest_get_irq
(QTestState *s, int num)¶
Parameters
QTestState * s
QTestState
instance to operate on.int num
Interrupt to observe.
Return
The level of the num interrupt.
-
void
qtest_irq_intercept_in
(QTestState *s, const char *string)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * string
QOM path of a device.
Description
Associate qtest irqs with the GPIO-in pins of the device whose path is specified by string.
-
void
qtest_irq_intercept_out
(QTestState *s, const char *string)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * string
QOM path of a device.
Description
Associate qtest irqs with the GPIO-out pins of the device whose path is specified by string.
-
void
qtest_set_irq_in
(QTestState *s, const char *string, const char *name, int irq, int level)¶
Parameters
QTestState * s
QTestState instance to operate on.
const char * string
QOM path of a device
const char * name
IRQ name
int irq
IRQ number
int level
IRQ level
Description
Force given device/irq GPIO-in pin to the given level.
-
void
qtest_outb
(QTestState *s, uint16_t addr, uint8_t value)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint16_t addr
I/O port to write to.
uint8_t value
Value being written.
Description
Write an 8-bit value to an I/O port.
-
void
qtest_outw
(QTestState *s, uint16_t addr, uint16_t value)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint16_t addr
I/O port to write to.
uint16_t value
Value being written.
Description
Write a 16-bit value to an I/O port.
-
void
qtest_outl
(QTestState *s, uint16_t addr, uint32_t value)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint16_t addr
I/O port to write to.
uint32_t value
Value being written.
Description
Write a 32-bit value to an I/O port.
-
uint8_t
qtest_inb
(QTestState *s, uint16_t addr)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint16_t addr
I/O port to read from.
Description
Returns an 8-bit value from an I/O port.
-
uint16_t
qtest_inw
(QTestState *s, uint16_t addr)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint16_t addr
I/O port to read from.
Description
Returns a 16-bit value from an I/O port.
-
uint32_t
qtest_inl
(QTestState *s, uint16_t addr)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint16_t addr
I/O port to read from.
Description
Returns a 32-bit value from an I/O port.
-
void
qtest_writeb
(QTestState *s, uint64_t addr, uint8_t value)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to write to.
uint8_t value
Value being written.
Description
Writes an 8-bit value to memory.
-
void
qtest_writew
(QTestState *s, uint64_t addr, uint16_t value)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to write to.
uint16_t value
Value being written.
Description
Writes a 16-bit value to memory.
-
void
qtest_writel
(QTestState *s, uint64_t addr, uint32_t value)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to write to.
uint32_t value
Value being written.
Description
Writes a 32-bit value to memory.
-
void
qtest_writeq
(QTestState *s, uint64_t addr, uint64_t value)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to write to.
uint64_t value
Value being written.
Description
Writes a 64-bit value to memory.
-
uint8_t
qtest_readb
(QTestState *s, uint64_t addr)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to read from.
Description
Reads an 8-bit value from memory.
Return
Value read.
-
uint16_t
qtest_readw
(QTestState *s, uint64_t addr)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to read from.
Description
Reads a 16-bit value from memory.
Return
Value read.
-
uint32_t
qtest_readl
(QTestState *s, uint64_t addr)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to read from.
Description
Reads a 32-bit value from memory.
Return
Value read.
-
uint64_t
qtest_readq
(QTestState *s, uint64_t addr)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to read from.
Description
Reads a 64-bit value from memory.
Return
Value read.
-
void
qtest_memread
(QTestState *s, uint64_t addr, void *data, size_t size)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to read from.
void * data
Pointer to where memory contents will be stored.
size_t size
Number of bytes to read.
Description
Read guest memory into a buffer.
-
uint64_t
qtest_rtas_call
(QTestState *s, const char *name, uint32_t nargs, uint64_t args, uint32_t nret, uint64_t ret)¶
Parameters
QTestState * s
QTestState
instance to operate on.const char * name
name of the command to call.
uint32_t nargs
Number of args.
uint64_t args
Guest address to read args from.
uint32_t nret
Number of return value.
uint64_t ret
Guest address to write return values to.
Description
Call an RTAS function
-
void
qtest_bufread
(QTestState *s, uint64_t addr, void *data, size_t size)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to read from.
void * data
Pointer to where memory contents will be stored.
size_t size
Number of bytes to read.
Description
Read guest memory into a buffer and receive using a base64 encoding.
-
void
qtest_memwrite
(QTestState *s, uint64_t addr, const void *data, size_t size)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to write to.
const void * data
Pointer to the bytes that will be written to guest memory.
size_t size
Number of bytes to write.
Description
Write a buffer to guest memory.
-
void
qtest_bufwrite
(QTestState *s, uint64_t addr, const void *data, size_t size)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to write to.
const void * data
Pointer to the bytes that will be written to guest memory.
size_t size
Number of bytes to write.
Description
Write a buffer to guest memory and transmit using a base64 encoding.
-
void
qtest_memset
(QTestState *s, uint64_t addr, uint8_t patt, size_t size)¶
Parameters
QTestState * s
QTestState
instance to operate on.uint64_t addr
Guest address to write to.
uint8_t patt
Byte pattern to fill the guest memory region with.
size_t size
Number of bytes to write.
Description
Write a pattern to guest memory.
-
int64_t
qtest_clock_step_next
(QTestState *s)¶
Parameters
QTestState * s
QTestState
instance to operate on.
Description
Advance the QEMU_CLOCK_VIRTUAL to the next deadline.
Return
The current value of the QEMU_CLOCK_VIRTUAL in nanoseconds.
-
int64_t
qtest_clock_step
(QTestState *s, int64_t step)¶
Parameters
QTestState * s
QTestState instance to operate on.
int64_t step
Number of nanoseconds to advance the clock by.
Description
Advance the QEMU_CLOCK_VIRTUAL by step nanoseconds.
Return
The current value of the QEMU_CLOCK_VIRTUAL in nanoseconds.
-
int64_t
qtest_clock_set
(QTestState *s, int64_t val)¶
Parameters
QTestState * s
QTestState instance to operate on.
int64_t val
Nanoseconds value to advance the clock to.
Description
Advance the QEMU_CLOCK_VIRTUAL to val nanoseconds since the VM was launched.
Return
The current value of the QEMU_CLOCK_VIRTUAL in nanoseconds.
-
bool
qtest_big_endian
(QTestState *s)¶
Parameters
QTestState * s
QTestState instance to operate on.
Return
True if the architecture under test has a big endian configuration.
-
const char *
qtest_get_arch
(void)¶
Parameters
void
no arguments
Return
The architecture for the QEMU executable under test.
-
void
qtest_add_func
(const char *str, void (*fn)(void))¶
Parameters
const char * str
Test case path.
void (*)(void) fn
Test case function
Description
Add a GTester testcase with the given name and function. The path is prefixed with the architecture under test, as returned by qtest_get_arch().
-
void
qtest_add_data_func
(const char *str, const void *data, void (*fn)(const void*))¶
Parameters
const char * str
Test case path.
const void * data
Test case data
void (*)(const void *) fn
Test case function
Description
Add a GTester testcase with the given name, data and function. The path is prefixed with the architecture under test, as returned by qtest_get_arch().
-
void
qtest_add_data_func_full
(const char *str, void *data, void (*fn)(const void*), GDestroyNotify data_free_func, )¶
Parameters
const char * str
Test case path.
void * data
Test case data
void (*)(const void *) fn
Test case function
GDestroyNotify data_free_func
GDestroyNotify for data
Description
Add a GTester testcase with the given name, data and function. The path is prefixed with the architecture under test, as returned by qtest_get_arch().
data is passed to data_free_func() on test completion.
-
qtest_add
(testpath, Fixture, tdata, fsetup, ftest, fteardown)¶
Parameters
testpath
Test case path
Fixture
Fixture type
tdata
Test case data
fsetup
Test case setup function
ftest
Test case function
fteardown
Test case teardown function
Description
Add a GTester testcase with the given name, data and functions. The path is prefixed with the architecture under test, as returned by qtest_get_arch().
-
void
qtest_qmp_assert_success
(QTestState *qts, const char *fmt, ...)¶
Parameters
QTestState * qts
QTestState instance to operate on
const char * fmt
QMP message to send to qemu, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
...
variable arguments
Description
Sends a QMP message to QEMU and asserts that a ‘return’ key is present in the response.
-
void
qtest_cb_for_every_machine
(void (*cb)(const char *machine), bool skip_old_versioned, )¶
Parameters
void (*)(const char *machine) cb
Pointer to the callback function
bool skip_old_versioned
true if versioned old machine types should be skipped
Description
Call a callback function for every name of all available machines.
-
void
qtest_qmp_device_add_qdict
(QTestState *qts, const char *drv, const QDict *arguments)¶
Parameters
QTestState * qts
QTestState instance to operate on
const char * drv
Name of the device that should be added
const QDict * arguments
QDict with properties for the device to intialize
Description
Generic hot-plugging test via the device_add QMP command with properties supplied in form of QDict. Use NULL for empty properties list.
-
void
qtest_qmp_device_add
(QTestState *qts, const char *driver, const char *id, const char *fmt, ...)¶
Parameters
QTestState * qts
QTestState instance to operate on
const char * driver
Name of the device that should be added
const char * id
Identification string
const char * fmt
QMP message to send to qemu, formatted like qobject_from_jsonf_nofail(). See parse_interpolation() for what’s supported after ‘%’.
...
variable arguments
Description
Generic hot-plugging test via the device_add QMP command.
-
void
qtest_qmp_device_del
(QTestState *qts, const char *id)¶
Parameters
QTestState * qts
QTestState instance to operate on
const char * id
Identification string
Description
Generic hot-unplugging test via the device_del QMP command.
-
bool
qmp_rsp_is_err
(QDict *rsp)¶
Parameters
QDict * rsp
QMP response to check for error
Description
Test rsp for error and discard rsp. Returns ‘true’ if there is error in rsp and ‘false’ otherwise.
-
void
qmp_expect_error_and_unref
(QDict *rsp, const char *class)¶
Parameters
QDict * rsp
QMP response to check for error
const char * class
an error class
Description
Assert the response has the given error class and discard rsp.
-
bool
qtest_probe_child
(QTestState *s)¶
Parameters
QTestState * s
QTestState instance to operate on.
Return
true if the child is still alive.
-
void
qtest_set_expected_status
(QTestState *s, int status)¶
Parameters
QTestState * s
QTestState instance to operate on.
int status
an expected exit status.
Description
Set expected exit status of the child.