Re: [PATCH 5/5 V2] kvm tools: Initialize and use VESA and VNC

Pekka Enberg
2011-05-23T11:45:12Z

On 5/23/11 2:38 PM, Ingo Molnar wrote:
> * Sasha Levin<levinsasha928@gmail.com> wrote:
>
>> @@ -511,7 +515,13 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
>> kvm->nrcpus = nrcpus;
>>
>> memset(real_cmdline, 0, sizeof(real_cmdline));
>> - strcpy(real_cmdline, "notsc noapic noacpi pci=conf1 console=ttyS0 earlyprintk=serial");
>> + strcpy(real_cmdline, "notsc noapic noacpi pci=conf1");
>> + if (vnc) {
>> + strcat(real_cmdline, " video=vesafb console=tty0");
>> + vidmode = 0x312;
>> + } else {
>> + strcat(real_cmdline, " console=ttyS0 earlyprintk=serial");
>> + }
> Hm, i think all the kernel parameter handling code wants to move into driver
> specific routines as well. Something like:
>
> serial_init(kvm, real_cmdline);
>
> where serial_init() would append to real_cmdline if needed.
>
> This removes a bit of serial-driver specific knowledge from kvm-run.c.
>
> Same goes for the VESA driver and the above video mode flag logic.
>
>> @@ -597,6 +607,9 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
>>
>> kvm__init_ram(kvm);
>>
>> + if (vnc)
>> + vesa__init(kvm);
> Shouldnt vesa__init() itself know about whether it's active (i.e. the 'vnc'
> flag is set) and return early if it's not set?
>
> That way this could become more encapsulated and self-sufficient:
>
> vesa__init(kvm);
>
> With no VESA driver specific state exposed to the generic kvm_cmd_run()
> function.
>
> Ideally kvm_cmd_run() hould just be a series of:
>
> serial_init(kvm, real_cmdline);
> vesa_init(kvm, real_cmdline);
> ...
>
> initialization routines. Later on even this could be removed: using section
> tricks we can put init functions into a section and drivers could register
> their init function like initcall(func) functions are registered within the
> kernel. kvm_cmd_run() could thus iterate over that (build time constructed)
> section like this:
>
> extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
>
> static void __init do_initcalls(void)
> {
> initcall_t *fn;
>
> for (fn = __early_initcall_end; fn< __initcall_end; fn++)
> do_one_initcall(*fn);
> }
>
> and would not actually have *any* knowledge about what drivers were built in.
>
> Currently it's fine to initialize everything explicitly - but this would be the
> long term model to work towards ...

Prasad, didn't you have patches to do exactly that?