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From 649497d1a3676020802ebba04a3d9bb31253adb5 Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@redhat.com>
Date: Tue, 28 Dec 2010 12:09:07 +0200
Subject: [PATCH 26/66] 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>
---
 arch/x86/kvm/mmu.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index fb8b376..fbb04ae 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -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);
-- 
1.6.6.1