KVM: VMX: Heed the 'msr' argument in msr_write_intercepted()

Regardless of the 'msr' argument passed to the VMX version of
msr_write_intercepted(), the function always checks to see if a
specific MSR (IA32_SPEC_CTRL) is intercepted for write.  This behavior
seems unintentional and unexpected.

Modify the function so that it checks to see if the provided 'msr'
index is intercepted for write.

Fixes: 67f4b996 ("KVM: nVMX: Handle dynamic MSR intercept toggling")
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220810213050.2655000-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmx.c

@@ -843,8 +843,7 @@ static bool msr_write_intercepted(struct vcpu_vmx *vmx, u32 msr)
 	if (!(exec_controls_get(vmx) & CPU_BASED_USE_MSR_BITMAPS))
 		return true;
 
-	return vmx_test_msr_bitmap_write(vmx->loaded_vmcs->msr_bitmap,
-					 MSR_IA32_SPEC_CTRL);
+	return vmx_test_msr_bitmap_write(vmx->loaded_vmcs->msr_bitmap, msr);
 }
 
 unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx)