KVM: nVMX: Fix returned value of MSR_IA32_VMX_PROCBASED_CTLS

SDM says bits 1, 4-6, 8, 13-16, and 26 have to be set.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/vmx.h

@@ -51,6 +51,9 @@
 #define CPU_BASED_MONITOR_EXITING               0x20000000
 #define CPU_BASED_PAUSE_EXITING                 0x40000000
 #define CPU_BASED_ACTIVATE_SECONDARY_CONTROLS   0x80000000
+
+#define CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x0401e172
+
 /*
  * Definitions of Secondary Processor-Based VM-Execution Controls.
  */

arch/x86/kvm/vmx.c

@@ -2306,7 +2306,7 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	/* cpu-based controls */
 	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS,
 		nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high);
-	nested_vmx_procbased_ctls_low = 0;
+	nested_vmx_procbased_ctls_low = CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 	nested_vmx_procbased_ctls_high &=
 		CPU_BASED_VIRTUAL_INTR_PENDING |
 		CPU_BASED_VIRTUAL_NMI_PENDING | CPU_BASED_USE_TSC_OFFSETING |
@@ -2327,7 +2327,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 * can use it to avoid exits to L1 - even when L0 runs L2
 	 * without MSR bitmaps.
 	 */
-	nested_vmx_procbased_ctls_high |= CPU_BASED_USE_MSR_BITMAPS;
+	nested_vmx_procbased_ctls_high |= CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR |
+		CPU_BASED_USE_MSR_BITMAPS;
 
 	/* We support free control of CR3 access interception. */
 	nested_vmx_true_procbased_ctls_low = nested_vmx_procbased_ctls_low &