[bug report] KVM: VMX: Use GPA legality helpers to replace open coded equivalents

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

Hello Sean Christopherson,

Commit 636e8b733491 ("KVM: VMX: Use GPA legality helpers to replace
open coded equivalents") from Feb 3, 2021 (linux-next), leads to the
following Smatch static checker warning:

	arch/x86/kvm/vmx/nested.c:834 nested_vmx_check_msr_switch()
	warn: potential user controlled sizeof overflow 'addr + count * 16' '0-u64max + 16-68719476720'

arch/x86/kvm/vmx/nested.c
    827 static int nested_vmx_check_msr_switch(struct kvm_vcpu *vcpu,
    828                                        u32 count, u64 addr)
    829 {
    830         if (count == 0)
    831                 return 0;
    832 
    833         if (!kvm_vcpu_is_legal_aligned_gpa(vcpu, addr, 16) ||
--> 834             !kvm_vcpu_is_legal_gpa(vcpu, (addr + count * sizeof(struct vmx_msr_entry) - 1)))
                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Do we support kvm on 32bit systems?

    835                 return -EINVAL;
    836 
    837         return 0;
    838 }

regards,
dan carpenter