From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: Correct way of tracking reads on given gfn ?
Date: Mon, 09 Sep 2013 12:53:02 +0200
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Il 09/09/2013 12:22, SPA ha scritto:
> Thanks Paolo.
> 
> Is there a way where reads would trap ?
> 
> I explored a bit on PM_PRESENT_MASK.  Though its not READ bit, but a
> PRESENT bit,  it looks like it should generate traps on reads if this
> bit is reset. From code, looks like rmap_write_protect() like function
> I stated in previous mail should do. Would this approach work ? Are
> there any glaring problems with this approach ?

I cannot say right away.  Another way could be to set reserved bits to
generate EPT misconfigurations.  See ept_set_mmio_spte_mask and
is_mmio_spte.

This would trap both reads and writes.

Paolo