[Qemu-devel] [PATCH] tests/hexloader-test: Don't pass -nographic to the QEMU under test

[Qemu-devel] [PATCH] tests/hexloader-test: Don't pass -nographic to the QEMU under test

[Peter Maydell]

The hexloader test invokes QEMU with the -nographic argument. This
is unnecessary, because the qtest_initf() function will pass it
-display none, which suffices to disable the graphical window.
It also means that the QEMU process will make the stdin/stdout
O_NONBLOCK. Since O_NONBLOCK is not per-file descriptor but per
"file description", this non-blocking behaviour is then shared
with any other process that's using the stdin/stdout of the
'make check' run, including make itself. This can result in make
falling over with "make: write error: stdout" because it got
an unexpected EINTR trying to write output messages to the terminal.
This is particularly noticable if running 'make check' in a loop with
  while make check; do true; done
(It does not affect single make check runs so much because the
shell will remove the O_NONBLOCK status before it reads the
terminal for interactive input.)

Remove the unwanted -nographic argument.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
This seems to be sufficient to resolve my "make falls over"
issues with the current test harness and a build done for
arm targets; I haven't checked whether other test cases which
are specific to other target architectures might have similar
accidental O_NONBLOCK behaviour.

 tests/hexloader-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/hexloader-test.c b/tests/hexloader-test.c
index 834ed52c22b..8b7aa2d72d0 100644
--- a/tests/hexloader-test.c
+++ b/tests/hexloader-test.c
@@ -23,7 +23,7 @@ static void hex_loader_test(void)
     const unsigned int base_addr = 0x00010000;
 
     QTestState *s = qtest_initf(
-        "-M vexpress-a9 -nographic -device loader,file=tests/data/hex-loader/test.hex");
+        "-M vexpress-a9 -device loader,file=tests/data/hex-loader/test.hex");
 
     for (i = 0; i < 256; ++i) {
         uint8_t val = qtest_readb(s, base_addr + i);
-- 
2.19.2

Re: [Qemu-devel] [PATCH] tests/hexloader-test: Don't pass -nographic to the QEMU under test

[Thomas Huth]

On 2019-01-04 15:50, Peter Maydell wrote:
> The hexloader test invokes QEMU with the -nographic argument. This
> is unnecessary, because the qtest_initf() function will pass it
> -display none, which suffices to disable the graphical window.
> It also means that the QEMU process will make the stdin/stdout
> O_NONBLOCK. Since O_NONBLOCK is not per-file descriptor but per
> "file description", this non-blocking behaviour is then shared
> with any other process that's using the stdin/stdout of the
> 'make check' run, including make itself. This can result in make
> falling over with "make: write error: stdout" because it got
> an unexpected EINTR trying to write output messages to the terminal.
> This is particularly noticable if running 'make check' in a loop with
>   while make check; do true; done
> (It does not affect single make check runs so much because the
> shell will remove the O_NONBLOCK status before it reads the
> terminal for interactive input.)
> 
> Remove the unwanted -nographic argument.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> This seems to be sufficient to resolve my "make falls over"
> issues with the current test harness and a build done for
> arm targets; I haven't checked whether other test cases which
> are specific to other target architectures might have similar
> accidental O_NONBLOCK behaviour.
> 
>  tests/hexloader-test.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/hexloader-test.c b/tests/hexloader-test.c
> index 834ed52c22b..8b7aa2d72d0 100644
> --- a/tests/hexloader-test.c
> +++ b/tests/hexloader-test.c
> @@ -23,7 +23,7 @@ static void hex_loader_test(void)
>      const unsigned int base_addr = 0x00010000;
>  
>      QTestState *s = qtest_initf(
> -        "-M vexpress-a9 -nographic -device loader,file=tests/data/hex-loader/test.hex");
> +        "-M vexpress-a9 -device loader,file=tests/data/hex-loader/test.hex");
>  
>      for (i = 0; i < 256; ++i) {
>          uint8_t val = qtest_readb(s, base_addr + i);

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [Qemu-devel] [PATCH] tests/hexloader-test: Don't pass -nographic to the QEMU under test

[Paolo Bonzini]

On 04/01/19 15:50, Peter Maydell wrote:
> The hexloader test invokes QEMU with the -nographic argument. This
> is unnecessary, because the qtest_initf() function will pass it
> -display none, which suffices to disable the graphical window.
> It also means that the QEMU process will make the stdin/stdout
> O_NONBLOCK. Since O_NONBLOCK is not per-file descriptor but per
> "file description", this non-blocking behaviour is then shared
> with any other process that's using the stdin/stdout of the
> 'make check' run, including make itself. This can result in make
> falling over with "make: write error: stdout" because it got
> an unexpected EINTR trying to write output messages to the terminal.
> This is particularly noticable if running 'make check' in a loop with
>   while make check; do true; done
> (It does not affect single make check runs so much because the
> shell will remove the O_NONBLOCK status before it reads the
> terminal for interactive input.)
> 
> Remove the unwanted -nographic argument.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> This seems to be sufficient to resolve my "make falls over"
> issues with the current test harness and a build done for
> arm targets; I haven't checked whether other test cases which
> are specific to other target architectures might have similar
> accidental O_NONBLOCK behaviour.
> 
>  tests/hexloader-test.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/hexloader-test.c b/tests/hexloader-test.c
> index 834ed52c22b..8b7aa2d72d0 100644
> --- a/tests/hexloader-test.c
> +++ b/tests/hexloader-test.c
> @@ -23,7 +23,7 @@ static void hex_loader_test(void)
>      const unsigned int base_addr = 0x00010000;
>  
>      QTestState *s = qtest_initf(
> -        "-M vexpress-a9 -nographic -device loader,file=tests/data/hex-loader/test.hex");
> +        "-M vexpress-a9 -device loader,file=tests/data/hex-loader/test.hex");
>  
>      for (i = 0; i < 256; ++i) {
>          uint8_t val = qtest_readb(s, base_addr + i);
> 

Great, I'll put it in my pull request together with the TAP driver
(however, I'll also put in the </dev/null for good measure).

Paolo