Re: [PATCH 1/3] xen: Add instruction length parameter in function hvm_inject_exception

[Keir Fraser <keir@xen.org>]

On 25/05/2012 20:17, "Aravindh Puthiyaparambil" <aravindh@virtuata.com>
wrote:

>> I don't like adding yet another parameter for all callers, especially as we
>> should also be passing down the event type (sw interrupt, hw exception, ...)
>> and that would bloat the parameter list further.
>> 
>> I attach a cleanup patch which packs everything into a new struct and
>> renames hvm_inject_exception to hvm_inject_trap. I then define a couple of
>> wrappers around that function for existing callers, so that their parameter
>> lists actually *shrink*.
>> 
>> Let me know what you think. If it looks acceptable I can check it in and we
>> can build on top of this restructuring. The aim being to keep
>> hvm/vmx_inject_trap dumb, and push down the knowledge from the callers into
>> it.
> 
> So I take it that with just this patch injecting of software
> interrupts will not work and I should hold off on testing that out.
> What is the plan for injecting software interrupts? Add another libxc
> API for that?

Yes, everything represented in my 'struct hvm_trap', plus instruction
length, which my patch doesn't add, should be part of the trap injection API
through hvm_op hypercall and libxc. So the toolstack can inject an arbitrary
trap type, on an arbitrary vector, specify an error code (and cr2 for page
fault), and specify an increment for rIP when the trap is successfully
injected. All through one API function.

But as you say, my patch is just a proposed refactoring basis for Xudong's
patches. It actually almost certainly reverts some behaviour that you guys
actually want, which then gets added back in more sanely in patches that go
on top.

 -- Keir