diff options
Diffstat (limited to 'drivers/kvm')
| -rw-r--r-- | drivers/kvm/kvm_main.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 0675d3e5169..67c1154960f 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -463,7 +463,19 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) vcpu->cr3 = cr3; spin_lock(&vcpu->kvm->lock); - vcpu->mmu.new_cr3(vcpu); + /* + * Does the new cr3 value map to physical memory? (Note, we + * catch an invalid cr3 even in real-mode, because it would + * cause trouble later on when we turn on paging anyway.) + * + * A real CPU would silently accept an invalid cr3 and would + * attempt to use it - with largely undefined (and often hard + * to debug) behavior on the guest side. + */ + if (unlikely(!gfn_to_memslot(vcpu->kvm, cr3 >> PAGE_SHIFT))) + inject_gp(vcpu); + else + vcpu->mmu.new_cr3(vcpu); spin_unlock(&vcpu->kvm->lock); } EXPORT_SYMBOL_GPL(set_cr3); |