On Wed, Feb 27, 2013 at 09:42:50AM -0600, Anthony Liguori wrote:
Paolo Bonzini <pbonzini@redhat.com> writes:
Il 26/02/2013 20:35, Anthony Liguori ha scritto:
> > See also discussion on multi-valued keys in command line option > arguments and config files in v1 thread. Hopefully we can reach a > conclusion soon, and then we'll see whether this patch is what we want.
Yeah, let's drop this patch by now. I am starting to be convinced that "cpus=A,cpus=B,cpus=C" is the best approach. It is not pretty, but at least it uses generic parser code instead of yet another ad-hoc parser. No, we cannot rely on this behavior. We had to do it to support backwards compat with netdev but it should not be used anywhere else.
We chose a config format (git's) because it was a good match for QemuOpts, and multiple-valued operations are well supported by that config format; see git-config(1). There is no reason to consider it a backwards-compatibility hack.
There's such thing as list support in QemuOpts. [skipping stuff about internal implementation details that don't matter]
If we want to have list syntax, we need to introduce first class support for it.
Absolutely. But how the syntax for it should look like?
Here's a simple example of how to do this. Obviously we would want to introduce some better error checking so we can catch if someone tries to access a list with a non-list accessor. We also would need list accessor functions.
But it's really not hard at all.
Of course. Once we decide how the syntax will look like, implementing it should be very easy. But as far as I can see, we were trying to discuss what's the appropriate syntax, here. I still don't see why "option=A:B:C" with no possibility of having list items containing ":" (like your proposal below) is a better generic syntax for lists than "option=A,option=B,option=C".
From 4ee7ed36d597f0defd78baac7480ecb29e11e1c1 Mon Sep 17 00:00:00 2001 From: Anthony Liguori <aliguori@us.ibm.com> Date: Wed, 27 Feb 2013 09:32:09 -0600 Subject: [PATCH] qemu-opts: support lists
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> --- include/qemu/option.h | 2 ++ util/qemu-option.c | 12 ++++++++++++ 2 files changed, 14 insertions(+)
diff --git a/include/qemu/option.h b/include/qemu/option.h index ba197cd..e4808c3 100644 --- a/include/qemu/option.h +++ b/include/qemu/option.h @@ -41,6 +41,7 @@ enum QEMUOptionParType { typedef struct QEMUOptionParameter { const char *name; enum QEMUOptionParType type; + bool list; union { uint64_t n; char* s; @@ -95,6 +96,7 @@ enum QemuOptType { typedef struct QemuOptDesc { const char *name; enum QemuOptType type; + bool list; const char *help; } QemuOptDesc;
diff --git a/util/qemu-option.c b/util/qemu-option.c index 5a1d03c..6b1ae6e 100644 --- a/util/qemu-option.c +++ b/util/qemu-option.c @@ -636,6 +636,18 @@ static void opt_set(QemuOpts *opts, const char *name, const char *value, return; }
+ if (desc->list && strchr(value, ':')) { + gchar **tokens = g_strsplit(value, ":", 0); + int i; + for (i = 0; tokens[i]; i++) { + opt_set(opts, name, tokens[i], prepend, errp); + if (error_is_set(errp)) { + return; + } + } + g_strfreev(tokens); + } + opt = g_malloc0(sizeof(*opt)); opt->name = g_strdup(name); opt->opts = opts; -- 1.8.0
Regards,
Anthony Liguori
Paolo
-- Eduardo