KVM: nVMX: Move VM-Fail check out of nested_vmx_exit_reflected()

Check for VM-Fail on nested VM-Enter in nested_vmx_reflect_vmexit() in
preparation for separating nested_vmx_exit_reflected() into separate "L0
wants exit exit" and "L1 wants the exit" helpers.

Explicitly set exit_intr_info and exit_qual to zero instead of reading
them from vmcs02, as they are invalid on VM-Fail (and thankfully ignored
by nested_vmx_vmexit() for nested VM-Fail).

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200415175519.14230-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index afc8c35..cb7fd78 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5652,15 +5652,6 @@ static bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason)
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
 
-       WARN_ON_ONCE(vmx->nested.nested_run_pending);
-
-       if (unlikely(vmx->fail)) {
-               trace_kvm_nested_vmenter_failed(
-                       "hardware VM-instruction error: ",
-                       vmcs_read32(VM_INSTRUCTION_ERROR));
-               return true;
-       }
-
        trace_kvm_nested_vmexit(kvm_rip_read(vcpu), exit_reason,
                                vmcs_readl(EXIT_QUALIFICATION),
                                vmx->idt_vectoring_info,
@@ -5819,7 +5810,23 @@ static bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason)
  */
 bool nested_vmx_reflect_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason)
 {
-       u32 exit_intr_info;
+       struct vcpu_vmx *vmx = to_vmx(vcpu);
+       u32 exit_intr_info, exit_qual;
+
+       WARN_ON_ONCE(vmx->nested.nested_run_pending);
+
+       /*
+        * Late nested VM-Fail shares the same flow as nested VM-Exit since KVM
+        * has already loaded L2's state.
+        */
+       if (unlikely(vmx->fail)) {
+               trace_kvm_nested_vmenter_failed(
+                       "hardware VM-instruction error: ",
+                       vmcs_read32(VM_INSTRUCTION_ERROR));
+               exit_intr_info = 0;
+               exit_qual = 0;
+               goto reflect_vmexit;
+       }
 
        if (!nested_vmx_exit_reflected(vcpu, exit_reason))
                return false;
@@ -5840,9 +5847,10 @@ bool nested_vmx_reflect_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason)
                vmcs12->vm_exit_intr_error_code =
                        vmcs_read32(VM_EXIT_INTR_ERROR_CODE);
        }
+       exit_qual = vmcs_readl(EXIT_QUALIFICATION);
 
-       nested_vmx_vmexit(vcpu, exit_reason, exit_intr_info,
-                         vmcs_readl(EXIT_QUALIFICATION));
+reflect_vmexit:
+       nested_vmx_vmexit(vcpu, exit_reason, exit_intr_info, exit_qual);
        return true;
 }