[RFC PATCH v6 29/36] KVM: VMX: Add missing CPU based VM execution controls to vmcs_config

Sean Christopherson
2022-08-24T03:04:50Z

As a preparation to reusing the result of setup_vmcs_config() in
nested VMX MSR setup, add the CPU based VM execution controls which KVM
doesn't use but supports for nVMX to KVM_OPT_VMX_CPU_BASED_VM_EXEC_CONTROL
and filter them out in vmx_exec_control().

No functional change intended.

Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/vmx.c | 9 +++++++++
arch/x86/kvm/vmx/vmx.h | 6 +++++-
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 079cc4835248..11e75f2b832f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4322,6 +4322,15 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx)
{
u32 exec_control = vmcs_config.cpu_based_exec_ctrl;

+ /*
+ * Not used by KVM, but fully supported for nesting, i.e. are allowed in
+ * vmcs12 and propagated to vmcs02 when set in vmcs12.
+ */
+ exec_control &= ~(CPU_BASED_RDTSC_EXITING |
+ CPU_BASED_USE_IO_BITMAPS |
+ CPU_BASED_MONITOR_TRAP_FLAG |
+ CPU_BASED_PAUSE_EXITING);
+
/* INTR_WINDOW_EXITING and NMI_WINDOW_EXITING are toggled dynamically */
exec_control &= ~(CPU_BASED_INTR_WINDOW_EXITING |
CPU_BASED_NMI_WINDOW_EXITING);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index ce99704a37b7..8a05d24f4167 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -551,9 +551,13 @@ static inline u8 vmx_get_rvi(void)
#endif

#define KVM_OPTIONAL_VMX_CPU_BASED_VM_EXEC_CONTROL \
- (CPU_BASED_TPR_SHADOW | \
+ (CPU_BASED_RDTSC_EXITING | \
+ CPU_BASED_TPR_SHADOW | \
+ CPU_BASED_USE_IO_BITMAPS | \
+ CPU_BASED_MONITOR_TRAP_FLAG | \
CPU_BASED_USE_MSR_BITMAPS | \
CPU_BASED_NMI_WINDOW_EXITING | \
+ CPU_BASED_PAUSE_EXITING | \
CPU_BASED_ACTIVATE_SECONDARY_CONTROLS | \
CPU_BASED_ACTIVATE_TERTIARY_CONTROLS)

--
2.37.1.595.g718a3a8f04-goog