Re: [PATCH] tests/avocado: raspi2_initrd: Wait for guest shutdown message before stopping

[Richard Henderson <richard.henderson@linaro.org>]

On 10/20/22 20:20, Peter Maydell wrote:
> The avocado test
>   tests/avocado/boot_linux_console.py:BootLinuxConsole.test_arm_raspi2_initrd
> finishes wiith
> 
>      exec_command(self, 'halt')
>      # Wait for VM to shut down gracefully
>      self.vm.wait()
> 
> In theory this should be fine. In practice it runs into two bugs:
> 
>   * when the test calls self.vm.wait() Avocado closes the socket
>     connection to the guest serial console immediately, so the
>     avocado logs don't have the last part of the guest output:
>     https://gitlab.com/qemu-project/qemu/-/issues/1265
>   * when the socket is closed, a bug in the QEMU socket chardev
>     means that it loses any data that the guest UART has not
>     yet consumed. This means that the guest doesn't always read
>     the full 'halt' command string, so the test intermittently
>     fails with a timeout:
>     https://gitlab.com/qemu-project/qemu/-/issues/1264
> 
> Work around both of these by waiting for the guest to print the
> string that means it has completed the shutdown process.  This fixes
> a very long standing intermittent failure in this test.
> 
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/636
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~