Re: [PATCH 1/7] KVM: Add a route layer to convert MSI message to GSI

[Avi Kivity <avi@redhat.com>]

Sheng Yang wrote:
> After reconsidering, I must say I prefer add/remove ioctls.
>
> About the code size, I don't think it would increase much. I've rewritten
> the code twice, I think I know the difference is little.
>   

:( sorry about that.

> For the option 2 route table ioctl, we got a array from userspace, and would
> convert it to linked list and keep it in kernel. That's a kind of must(I
> don't think you would prefer use a array in kernel), and it's very direct.
>   

Actually, eventually we'd want an array indexed by gsi.  Each element 
would be a pointer to another array (one or two routing entries).

Certainly we don't want to iterate a list which could hold several 
hundred interrupts for a large guest.

It's okay to start with a linked list, but eventually we'll want 
something faster.

> So, we have to insert/delete route entry for both. What's the real
> difference we do it one by one or do it all at once. I don't think it is
> much different on the code size. And it's indeed very clear and direct.
>
> Beside this, option 2 seems strange. Why should we handle this table in this
> way when it won't result in significant code reduce. Insert/delete entry it
> there, look up entry is also there, not many things changed. And it's not
> that direct as option 1, which also can be a source of bugs.
>
> How do you think?
>   

I'm not convinced.  Please post your latest, and I will post a 
counter-proposal.

-- 
error compiling committee.c: too many arguments to function