From: Vitaly Kuznetsov Date: Mon, 7 Jan 2019 18:44:51 +0000 (+0100) Subject: KVM: nSVM: clear events pending from svm_complete_interrupts() when exiting to L1 X-Git-Tag: v5.0-rc4~8^2~7 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=619ad846fc3452adaf71ca246c5aa711e2055398;p=linux.git KVM: nSVM: clear events pending from svm_complete_interrupts() when exiting to L1 kvm-unit-tests' eventinj "NMI failing on IDT" test results in NMI being delivered to the host (L1) when it's running nested. The problem seems to be: svm_complete_interrupts() raises 'nmi_injected' flag but later we decide to reflect EXIT_NPF to L1. The flag remains pending and we do NMI injection upon entry so it got delivered to L1 instead of L2. It seems that VMX code solves the same issue in prepare_vmcs12(), this was introduced with code refactoring in commit 5f3d5799974b ("KVM: nVMX: Rework event injection and recovery"). Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 8a0c9a1f6ac8..9caf1252c64a 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3414,6 +3414,14 @@ static int nested_svm_vmexit(struct vcpu_svm *svm) kvm_mmu_reset_context(&svm->vcpu); kvm_mmu_load(&svm->vcpu); + /* + * Drop what we picked up for L2 via svm_complete_interrupts() so it + * doesn't end up in L1. + */ + svm->vcpu.arch.nmi_injected = false; + kvm_clear_exception_queue(&svm->vcpu); + kvm_clear_interrupt_queue(&svm->vcpu); + return 0; }