KVM: x86: Add infrastructure for MSR filtering

In the following commits we will add pieces of MSR filtering.
To ensure that code compiles even with the feature half-merged, let's add
a few stubs and struct definitions before the real patches start.

Signed-off-by: Alexander Graf <graf@amazon.com>

Message-Id: <20200925143422.21718-4-graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/uapi/asm/kvm.h

@@ -192,6 +192,8 @@ struct kvm_msr_list {
 	__u32 indices[0];
 };
 
+#define KVM_MSR_FILTER_READ  (1 << 0)
+#define KVM_MSR_FILTER_WRITE (1 << 1)
 
 struct kvm_cpuid_entry {
 	__u32 function;