From 2e53d63acba75795aa226febd140f67c58c6a353 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Wed, 20 Feb 2008 14:47:24 -0500 Subject: KVM: MMU: ignore zapped root pagetables Mark zapped root pagetables as invalid and ignore such pages during lookup. This is a problem with the cr3-target feature, where a zapped root table fools the faulting code into creating a read-only mapping. The result is a lockup if the instruction can't be emulated. Signed-off-by: Marcelo Tosatti Cc: Anthony Liguori Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0dd038e7392b..e8e64927bddc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2658,6 +2658,10 @@ preempted: kvm_x86_ops->guest_debug_pre(vcpu); again: + if (vcpu->requests) + if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests)) + kvm_mmu_unload(vcpu); + r = kvm_mmu_reload(vcpu); if (unlikely(r)) goto out; @@ -2689,6 +2693,14 @@ again: goto out; } + if (vcpu->requests) + if (test_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests)) { + local_irq_enable(); + preempt_enable(); + r = 1; + goto out; + } + if (signal_pending(current)) { local_irq_enable(); preempt_enable(); -- cgit v1.2.3