KVM: selftests: Use "standard" min virtual address for Hyper-V pages

Use the de facto standard minimum virtual address for Hyper-V's hcall
params page.  It's the allocator's job to not double-allocate memory,
i.e. there's no reason to force different regions for the params vs.
hcall page.  This will allow adding a page allocation helper with a
"standard" minimum address.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622200529.3650424-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/x86_64/hyperv_features.c

@@ -629,7 +629,7 @@ int main(void)
 	hcall_page = vm_vaddr_alloc(vm, 2 * getpagesize(), 0x10000, 0, 0);
 	memset(addr_gva2hva(vm, hcall_page), 0x0, 2 * getpagesize());
 
-	hcall_params = vm_vaddr_alloc(vm, getpagesize(), 0x20000, 0, 0);
+	hcall_params = vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
 	memset(addr_gva2hva(vm, hcall_params), 0x0, getpagesize());
 
 	vcpu_args_set(vm, VCPU_ID, 2, addr_gva2gpa(vm, hcall_page), hcall_params);