Re: [Qemu-devel] [PATCH v3 4/6] qemu-option: support +foo/-foo command line agruments

["Andreas Färber" <afaerber@suse.de>]

Am 11.11.2013 13:52, schrieb Jan Kiszka:
> On 2013-11-11 13:41, Andreas Färber wrote:
>> Am 11.11.2013 08:44, schrieb Alexey Kardashevskiy:
>>> This converts +foo/-foo to "foo=on"/"foo=off" respectively when
>>> QEMU parser is used for the command line options.
>>>
>>> "-cpu" parsers in x86 and other architectures should be unaffected
>>> by this change.
>>>
>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>> ---
>>>  util/qemu-option.c | 6 ++++++
>>>  1 file changed, 6 insertions(+)
>>>
>>> diff --git a/util/qemu-option.c b/util/qemu-option.c
>>> index efcb5dc..6c8667c 100644
>>> --- a/util/qemu-option.c
>>> +++ b/util/qemu-option.c
>>> @@ -890,6 +890,12 @@ static int opts_do_parse(QemuOpts *opts, const char *params,
>>>                  if (strncmp(option, "no", 2) == 0) {
>>>                      memmove(option, option+2, strlen(option+2)+1);
>>>                      pstrcpy(value, sizeof(value), "off");
>>> +                } else if (strncmp(option, "-", 1) == 0) {
>>> +                    memmove(option, option+1, strlen(option+1)+1);
>>> +                    pstrcpy(value, sizeof(value), "off");
>>> +                } else if (strncmp(option, "+", 1) == 0) {
>>> +                    memmove(option, option+1, strlen(option+1)+1);
>>> +                    pstrcpy(value, sizeof(value), "on");
>>>                  } else {
>>>                      pstrcpy(value, sizeof(value), "on");
>>>                  }
>>
>> This looks like an interesting idea! However this is much too big a
>> change to just CC ppc folks on...
>>
>> Jan, I wonder if this might break slirp's hostfwd option?
> 
> hostfwd starts with ":" in the simplest case - or what pattern do you
> have in mind?

Ah right, I had :8022-:22 or so in mind and mixed up optional host name
with optional source port.

Basically I'm checking for anything which is using the generic QemuOpts
parsing and where a literal + or - may lead to unexpected parsing
changes with this patch. Without having looked up more context for this
hunk, it should not affect foo=-bar but only where foo= is optional,
such as type names for driver= starting with either character (not aware
of such types though).

Andreas

>> Not sure what other options potentially starting with '-' might be
>> affected. Test cases would be a helpful way of demonstrating that this
>> change does not have undesired side effects.

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