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[PATCH] KVM: Make loading cr3 more robust 

Prevent the guest's loading of a corrupt cr3 (pointing at no guest phsyical
page) from crashing the host.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
hifive-unleashed-5.1
Ingo Molnar 2007-01-05 16:36:59 -08:00 committed by Linus Torvalds
parent 760db773fb
commit d21225ee2b
1 changed files with 13 additions and 1 deletions
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14
drivers/kvm/kvm_main.c
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@ -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);