From 0be9c7a89f75072e091cd079d76194aec8d1fb09 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Sun, 15 Sep 2013 11:07:23 +0300 Subject: KVM: VMX: set "blocked by NMI" flag if EPT violation happens during IRET from NMI Set "blocked by NMI" flag if EPT violation happens during IRET from NMI otherwise NMI can be called recursively causing stack corruption. Signed-off-by: Gleb Natapov --- arch/x86/kvm/vmx.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch/x86/kvm') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 48735936860c..a1216de9ffda 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5339,6 +5339,15 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu) return 0; } + /* + * EPT violation happened while executing iret from NMI, + * "blocked by NMI" bit has to be set before next VM entry. + * There are errata that may cause this bit to not be set: + * AAK134, BY25. + */ + if (exit_qualification & INTR_INFO_UNBLOCK_NMI) + vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); + gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS); trace_kvm_page_fault(gpa, exit_qualification); -- cgit v1.2.3