Re: [PATCH 1/2] system/vl.c: Fix handling of '-serial none -serial something'

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

On 1/23/24 02:36, Peter Maydell wrote:
> Currently if the user passes multiple -serial options on the command
> line, we mostly treat those as applying to the different serial
> devices in order, so that for example
>   -serial stdio -serialfile:filename
> will connect the first serial port to stdio and the second to the
> named file.
> 
> The exception to this is the '-serial none' serial device type.  This
> means "don't allocate this serial device", but a bug means that
> following -serial options are not correctly handled, so that
>   -serial none -serial stdio
> has the unexpected effect that stdio is connected to the first serial
> port, not the second.
> 
> This is a very long-standing bug that dates back at least as far as
> commit 998bbd74b9d81 from 2009.
> 
> Make the 'none' serial type move forward in the indexing of serial
> devices like all the other serial types, so that any subsequent
> -serial options are correctly handled.
> 
> Note that if your commandline mistakenly had a '-serial none' that
> was being overridden by a following '-serial something' option, you
> should delete the unnecessary '-serial none'.  This will give you the
> same behaviour as before, on QEMU versions both with and without this
> bug fix.
> 
> Cc:qemu-stable@nongnu.org
> Reported-by: Bohdan Kostiv<bohdan.kostiv@tii.ae>
> Fixes: 998bbd74b9d81 ("default devices: core code & serial lines")
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
> See the discussion of Bohdan's patch on the mailing list for
> further context:
> https://lore.kernel.org/qemu-devel/CAA3Sv1LQ8yDUNLCB5WqLVZjsHffrU0uSbL_YYJW_m+Db2PhEeQ@mail.gmail.com/
> ---
>   system/vl.c | 22 +++++++++++++---------
>   1 file changed, 13 insertions(+), 9 deletions(-)

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

r~