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kvm: mmu: fix is_tdp_mmu_check when the TDP MMU is not in use

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In some cases where shadow paging is in use, the root page will
be either mmu->pae_root or vcpu->arch.mmu->lm_root.  Then it will
not have an associated struct kvm_mmu_page, because it is allocated
with alloc_page instead of kvm_mmu_alloc_page.

Just return false quickly from is_tdp_mmu_root if the TDP MMU is
not in use, which also includes the case where shadow paging is
enabled.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2020-11-15 08:55:43 -05:00
parent 96308b0661
commit c887c9b9ca
1 changed files with 7 additions and 0 deletions
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7
arch/x86/kvm/mmu/tdp_mmu.c
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@ -49,7 +49,14 @@ bool is_tdp_mmu_root(struct kvm *kvm, hpa_t hpa)
{
struct kvm_mmu_page *sp;
if (!kvm->arch.tdp_mmu_enabled)
return false;
if (WARN_ON(!VALID_PAGE(hpa)))
return false;
sp = to_shadow_page(hpa);
if (WARN_ON(!sp))
return false;
return sp->tdp_mmu_page && sp->root_count;
}