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Re: [Xen-ia64-devel] [PATCH] translate_domain_pte must handle ED bit
On Mon, Feb 20, 2006 at 10:54:41PM +0800, Tian, Kevin wrote:
> >From: Isaku Yamahata
> >Sent: 2006年2月20日 16:32
> >translate_domain_pte() must handle ED bit explicitly.
> >This case can occur because of vcpu_itc_d().
> Seems a bug, however do you know why it only jumps out now? Seems PAGE_ED is
> likely on in lookup_domain_mpa...
Perhaps vcpu->arch.dtlb cache hit in vcpu_translate() is very rare
because of tlb cache and VHPT.
To hit this bug it would be necessary to run a huge amount of
guest domains competing tlb cache and VHPT entries.
It seems that no one does.
Otherwise artificial repeated vhpt/tlb flush in xen for debug might have
this bug appear.
> BTW, bit[53-63] are ignored bits per 184.108.40.206 of SDM2, and then you can just
> ignore them instead of BUG there. ;-)
Hmm, the current code seems to assume just simply that bit[53-63] and
ED bit can be used for address machine page frame number.
Some clean up might be needed.
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