Commit 649497d1 authored Dec 28, 2010 by Avi Kivity

KVM: MMU: Fix incorrect direct gfn for unpaged mode shadow

We use the physical address instead of the base gfn for the four
PAE page directories we use in unpaged mode.  When the guest accesses
an address above 1GB that is backed by a large host page, a BUG_ON()
in kvm_mmu_set_gfn() triggers.

Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=21962


Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com>
KVM-Stable-Tag.
Signed-off-by: Avi Kivity <avi@redhat.com>

parent 0a592281

arch/x86/kvm/mmu.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2394,7 +2394,8 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
		ASSERT(!VALID_PAGE(root));
		spin_lock(&vcpu->kvm->mmu_lock);
		kvm_mmu_free_some_pages(vcpu);
		sp = kvm_mmu_get_page(vcpu, i << 30, i << 30,
		sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT),
		i << 30,
		PT32_ROOT_LEVEL, 1, ACC_ALL,
		NULL);
		root = __pa(sp->spt);

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