Re: [Xen-ia64-devel] Strange code in vmx_init.c

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

On Mon, Sep 10, 2007 at 09:32:42AM +0800, Zhang, Xing Z wrote:
> I think Isaku have the answer. Is it related to MCA? 

No. It's for xm dump-core.
When I wrote the patch c/s 3c8039aa5004,
I thought the area should also be dumped to the file.
The fact that it uses v->arch.privregs seconded.

Yes, the guest shouldn't write to the area.
For that we can make it read-only by using ASSIGN_readonly.
If we think it's the infomation leak (i.e. the guest shouln't read the area),
another choice is not to dump the area.
With Tristan's get vcpu context patch the area isn't necessary
for the guest dump. Fortunatly the current crash utility doesn't look
the .xen_ia64_mmapped_regs section, the change won't break the compatibility.

My vote is the latter option. But I'm not sure the area should be dumped or not.


> 
> Good good study,day day up ! ^_^
> -Wing(zhang xin)
> 
> OTC,Intel Corporation
> >-----Original Message-----
> >From: xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx
> >[mailto:xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx] On
> >Behalf Of Tristan Gingold
> >Sent: 2007年9月8日 0:26
> >To: Xen-ia64-devel
> >Subject: [Xen-ia64-devel] Strange code in vmx_init.c
> >
> >Hi,
> >
> >in vms_final_setup_guest() I can read:
> >
> >     v->arch.privregs = (mapped_regs_t *)vpd;
> >     vcpu_share_privregs_with_guest(v);
> >
> >Why is vcpu_share_privregs_with_guest() called ?  Do we really
> >want make the
> >vpd writable by the guest software ?  Looks like a bug to me.
> >
> >Tristan.
> >
> >_______________________________________________
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-- 
yamahata

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