From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH  -v2] Monitor command: pfa2hva, translate guest physical
 address to host virtual address
Date: Wed, 10 Nov 2010 19:08:31 +0200
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Cc: Huang Ying <ying.huang@intel.com>,
	Anthony Liguori <aliguori@linux.vnet.ibm.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Anthony Liguori <aliguori@us.ibm.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Dean Nelson <dnelson@redhat.com>,
	Luiz Capitulino <lcapitulino@redhat.com>
To: Andi Kleen <andi@firstfloor.org>
Return-path: <kvm-owner@vger.kernel.org>
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On 11/10/2010 06:42 PM, Andi Kleen wrote:
> >  We need host kernel to break down the 2M huge page into 4k pages. Then
> >  send SIGBUS to QEMU with the poisoned 4k page. Because host kernel will
> >  poison the whole 2M virtual address space otherwise, and other 4k pages
> >  inside the 2M page can not used accessed in guest (will trigger SIGBUS
> >  and SRAR MCE).
>
> The easiest way would be to port the respective code from Andrea's
> transparent hugetlb patchkit. It already does break down huge pages
> as needed. You just have to be careful to not touch (/copy) the corrupted
> subpage.

Doing it in userspace in easier, since we can replace the vma for that 
section (and avoid mixed 4k/2M pages in hugetlbfs).

With transparent hugepages it's easy of course, you just call 
split_hugepage() and poison the 4k page.

-- 
error compiling committee.c: too many arguments to function