From 1abf23fb42f55eece2eefeea1b32aca865a14099 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <sean.j.christopherson@intel.com> Date: Wed, 26 Sep 2018 09:23:41 -0700 Subject: [PATCH] KVM: nVMX: use vm_exit_controls_init() to write exit controls for vmcs02 Write VM_EXIT_CONTROLS using vm_exit_controls_init() when configuring vmcs02, otherwise vm_exit_controls_shadow will be stale. EFER in particular can be corrupted if VM_EXIT_LOAD_IA32_EFER is not updated due to an incorrect shadow optimization, which can crash L0 due to EFER not being loaded on exit. This does not occur with the current code base simply because update_transition_efer() unconditionally clears VM_EXIT_LOAD_IA32_EFER before conditionally setting it, and because a nested guest always starts with VM_EXIT_LOAD_IA32_EFER clear, i.e. we'll only ever unnecessarily clear the bit. That is, until someone optimizes update_transition_efer()... Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/vmx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3831e0968d6a6..3c9c8ec168e42 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -12262,7 +12262,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, * we should use its exit controls. Note that VM_EXIT_LOAD_IA32_EFER * bits are further modified by vmx_set_efer() below. */ - vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl); + vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl); /* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are * emulated by vmx_set_efer(), below. -- GitLab