Messages in this thread | | | Date | Thu, 9 Dec 2021 01:21:47 +0000 | From | Sean Christopherson <> | Subject | Re: [PATCH 1/12] KVM: X86: Fix when shadow_root_level=5 && guest root_level<4 |
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On Thu, Dec 09, 2021, Sean Christopherson wrote: > On Wed, Nov 24, 2021, Lai Jiangshan wrote: > > From: Lai Jiangshan <laijs@linux.alibaba.com> > > > > If the is an L1 with nNPT in 32bit, the shadow walk starts with > > pae_root. > > > > Fixes: a717a780fc4e ("KVM: x86/mmu: Support shadowing NPT when 5-level paging is enabled in host) > > Have you actually run with 5-level nNPT? I don't have access to hardware, at least > not that I know of :-) > > I'm staring at kvm_mmu_sync_roots() and don't see how it can possibly work for > 5-level nNPT with a 4-level NPT guest.
Oh, and fast_pgd_switch() will also break kvm_mmu_sync_prev_roots() / is_unsync_root() by putting a root into the prev_roots array that doesn't have a shadow page associated with the root.
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