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RE: [Xen-devel] Re: Are linker scripts needed?

To: "Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>, "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx>
Subject: RE: [Xen-devel] Re: Are linker scripts needed?
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Tue, 24 May 2005 11:40:48 +0800
Cc: "Sharma, Arun" <arun.sharma@xxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx
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Thread-topic: [Xen-devel] Re: Are linker scripts needed?
>> I thought that VMX provided a virtual equivalent of SMM,
>> where management and emulation code can run under the OS's
>> feet without it realising? If this is not provided then I do
>> not think the trick can work, as you would need to steal some
>> virtual address space in which to execute the qemu code.
>
>I'd be inclined to move to a model where we execute the device
emulation
>in the root (monitor) VMCS, using the same protection mechanism we use
>for para-virtualized guests e.g. segmentation for x86, paging for
>x86_64. The device emulation should should work like a normal front-end
>driver, connecting via a device channel to a normal backend.

I like the idea. :) but where is the resource of device emulation
component getting allocation from, like physical frame allocated to that
module? If it's managed by vmx domain's kernel, I'm not sure it's easy
for such type of DM to acquire system resource and also access the user
eco system across multiple space, like:
        - page fault handle
        - Access special files like /proc/privcmd
        - Where are configuration files of qemu saved? In service OS
file system, or in vmx domain's FS?
        - How to sync between DM and corresponding vmx domain?
        ...

Also that style of DM will be another type of domain, which has to been
considered by HV specially with resource and schedule...

Just some immature concerns, and like to learn more in this direction.
:)

Thanks,
Kevin

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