KVM: x86: Take an unsigned 32-bit int for has_emulated_msr()'s index

Take a u32 for the index in has_emulated_msr() to match hardware, which
treats MSR indices as unsigned 32-bit values.  Functionally, taking a
signed int doesn't cause problems with the current code base, but could
theoretically cause problems with 32-bit KVM, e.g. if the index were
checked via a less-than statement, which would evaluate incorrectly for
MSR indices with bit 31 set.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200218234012.7110-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -1064,7 +1064,7 @@ struct kvm_x86_ops {
 	void (*hardware_disable)(void);
 	void (*hardware_unsetup)(void);
 	bool (*cpu_has_accelerated_tpr)(void);
-	bool (*has_emulated_msr)(int index);
+	bool (*has_emulated_msr)(u32 index);
 	void (*cpuid_update)(struct kvm_vcpu *vcpu);
 
 	unsigned int vm_size;

arch/x86/kvm/svm/svm.c

@@ -3525,7 +3525,7 @@ static bool svm_cpu_has_accelerated_tpr(void)
 	return false;
 }
 
-static bool svm_has_emulated_msr(int index)
+static bool svm_has_emulated_msr(u32 index)
 {
 	switch (index) {
 	case MSR_IA32_MCG_EXT_CTL:

arch/x86/kvm/vmx/vmx.c

@@ -6434,7 +6434,7 @@ static void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
 		handle_exception_nmi_irqoff(vmx);
 }
 
-static bool vmx_has_emulated_msr(int index)
+static bool vmx_has_emulated_msr(u32 index)
 {
 	switch (index) {
 	case MSR_IA32_SMBASE: