[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [RFC][PATCH 14/16] kvm: x86: Add user space part for in

From: Jan Kiszka
Subject: Re: [Qemu-devel] [RFC][PATCH 14/16] kvm: x86: Add user space part for in-kernel i8259
Date: Sun, 04 Dec 2011 16:19:24 +0100
User-agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv: Gecko/20080226 SUSE/ Thunderbird/ Mnenhy/

On 2011-12-04 16:12, Avi Kivity wrote:
> On 12/04/2011 04:06 PM, Jan Kiszka wrote:
>> On 2011-12-04 15:04, Avi Kivity wrote:
>>> On 12/04/2011 03:51 PM, Jan Kiszka wrote:
>>>>> But the name becomes part of the save/restore ABI, so you can't.
>>>> Nope, the vmstate names are identical. That would ruin migration
>>>> otherwise. It's just the output of info qtree & co. that changes.
>>> Oh, okay.  I still think it's wrong, but now it's just a matter of
>>> taste, and I can live with it.
>> Wrong in what sense?
> In the sense that kernel-apic is just an accelerated apic.  From the
> guest point of view, there's no difference, and that should be reflected
> in the device model.

That was my goal as well: The guest should not notice the difference,
but the admin on the host side should still be able to tell both
internally fairly different models apart. Plus the code should be
clearly split where there are differences and explicitly shared where
there aren't.

> If I'm reading an apic register, either from the guest or via a monitor
> debug interface, I shouldn't care whether it's accelerated or not.  The
> guest part already holds, of course.

Specifically for the debug scenario, I'd prefer the clear
differentiation by name as there can always remain subtle differences in
the implementation of kernel vs. user space. Someone debugging the guest
and/or qemu/kvm should remain aware of this.


Attachment: signature.asc
Description: OpenPGP digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]