KVM: nVMX: Fix content of MSR_IA32_VMX_ENTRY/EXIT_CTLS

Properly set those bits to 1 that the spec demands in case bit 55 of
VMX_BASIC is 0 - like in our case.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

2 files changed, 14 insertions, 3 deletions

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index b6fbf860e398..5fb6e24f0649 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -81,6 +81,8 @@
 #define VM_EXIT_LOAD_IA32_EFER                  0x00200000
 #define VM_EXIT_SAVE_VMX_PREEMPTION_TIMER       0x00400000
 
+#define VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR       0x00036dff
+
 #define VM_ENTRY_LOAD_DEBUG_CONTROLS            0x00000002
 #define VM_ENTRY_IA32E_MODE                     0x00000200
 #define VM_ENTRY_SMM                            0x00000400
@@ -89,6 +91,8 @@
 #define VM_ENTRY_LOAD_IA32_PAT                  0x00004000
 #define VM_ENTRY_LOAD_IA32_EFER                 0x00008000
 
+#define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR      0x000011ff
+
 /* VMCS Encodings */
 enum vmcs_field {
         VIRTUAL_PROCESSOR_ID            = 0x00000000,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index aacf6a458ae1..a9d885353108 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2049,21 +2049,28 @@ static __init void nested_vmx_setup_ctls_msrs(void)
                 PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING |
                 PIN_BASED_VIRTUAL_NMIS;
 
-        /* exit controls */
-        nested_vmx_exit_ctls_low = 0;
+        /*
+         * Exit controls
+         * If bit 55 of VMX_BASIC is off, bits 0-8 and 10, 11, 13, 14, 16 and
+         * 17 must be 1.
+         */
+        nested_vmx_exit_ctls_low = VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR;
         /* Note that guest use of VM_EXIT_ACK_INTR_ON_EXIT is not supported. */
 #ifdef CONFIG_X86_64
         nested_vmx_exit_ctls_high = VM_EXIT_HOST_ADDR_SPACE_SIZE;
 #else
         nested_vmx_exit_ctls_high = 0;
 #endif
+        nested_vmx_exit_ctls_high |= VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR;
 
         /* entry controls */
         rdmsr(MSR_IA32_VMX_ENTRY_CTLS,
                 nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high);
-        nested_vmx_entry_ctls_low = 0;
+        /* If bit 55 of VMX_BASIC is off, bits 0-8 and 12 must be 1. */
+        nested_vmx_entry_ctls_low = VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR;
         nested_vmx_entry_ctls_high &=
                 VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_IA32E_MODE;
+        nested_vmx_entry_ctls_high |= VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR;
 
         /* cpu-based controls */
         rdmsr(MSR_IA32_VMX_PROCBASED_CTLS,