Re: [Xen-devel] can dom0 modify Shadow PT of HVM domU?

To:	Wu Bingzheng <wubingzheng@xxxxxxx>, Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
Subject:	Re: [Xen-devel] can dom0 modify Shadow PT of HVM domU?
From:	Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date:	Wed, 26 Aug 2009 13:58:38 +0100
Cc:	xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
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On 26/08/2009 11:30, "Wu Bingzheng" <wubingzheng@xxxxxxx> wrote:

>> I see.  That seems like a pretty convoluted way of doing it.  Why don't
>> you just inject #GP (or whatever) straight into the guest from your dom0
>> hypercall?
> 
> I think vmx_inject_hw_exception() can't be called under dom0's context,
> because it calls __vmread() to read VMCS.

You can do vmx_vmcs_enter(v) at the very start of the function (before any
vmread or vmwrite) and vmx_vmcs_exit(v) at the very end. If you make this
change then it will be safe to call the function from dom0.

 -- Keir

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Re: [Xen-devel] can dom0 modify Shadow PT of HVM domU?