Messages in this thread | | | Date | Mon, 09 Sep 2013 12:12:23 +0200 | From | Paolo Bonzini <> | Subject | Re: [PATCH v2] KVM: mmu: allow page tables to be in read-only slots |
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Il 08/09/2013 11:04, Gleb Natapov ha scritto: > On Thu, Sep 05, 2013 at 02:21:53PM +0200, Paolo Bonzini wrote: >> Page tables in a read-only memory slot will currently cause a triple >> fault when running with shadow paging, because the page walker uses >> gfn_to_hva and it fails on such a slot. >> >> TianoCore uses such a page table. The idea is that, on real hardware, >> the firmware can already run in 64-bit flat mode when setting up the >> memory controller. Real hardware seems to be fine with that as long as >> the accessed/dirty bits are set. Thus, this patch saves whether the >> slot is readonly, and later checks it when updating the accessed and >> dirty bits. >> >> Note that this scenario is not supported by NPT at all, as explained by >> comments in the code. >> >> Cc: stable@vger.kernel.org >> Cc: kvm@vger.kernel.org >> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> >> Cc: Gleb Natapov <gleb@redhat.com> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > I would prefer to change gfn_to_hva_read() to gfn_to_hva_prot() in this > patch already, it will not make it any bigger
Sure.
Paolo
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