KVM: selftests: Clean up misnomers in xen_shinfo_test

As discussed[*], relabel the poorly named structs to align with the
current KVM nomenclature.

Old names are a leftover from before commit 52491a3 ("KVM:
Initialize gfn_to_pfn_cache locks in dedicated helper"), which i.a.
introduced kvm_gpc_init() and renamed kvm_gfn_to_pfn_cache_init()/
_destroy() to kvm_gpc_activate()/_deactivate(). Partly in an effort
to avoid implying that the cache really is destroyed/freed.

While at it, get rid of #define GPA_INVALID, which being used as a GFN,
is not only misnamed, but also unnecessarily reinvents a UAPI constant.

No functional change intended.

[*] https://lore.kernel.org/r/Y5yZ6CFkEMBqyJ6v@google.com

Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://lore.kernel.org/r/20230206202430.1898057-1-mhal@rbox.co
Signed-off-by: Sean Christopherson <seanjc@google.com>

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

@@ -19,9 +19,6 @@
 
 #include <sys/eventfd.h>
 
-/* Defined in include/linux/kvm_types.h */
-#define GPA_INVALID		(~(ulong)0)
-
 #define SHINFO_REGION_GVA	0xc0000000ULL
 #define SHINFO_REGION_GPA	0xc0000000ULL
 #define SHINFO_REGION_SLOT	10
@@ -412,19 +409,19 @@ static void *juggle_shinfo_state(void *arg)
 {
 	struct kvm_vm *vm = (struct kvm_vm *)arg;
 
-	struct kvm_xen_hvm_attr cache_init = {
+	struct kvm_xen_hvm_attr cache_activate = {
 		.type = KVM_XEN_ATTR_TYPE_SHARED_INFO,
 		.u.shared_info.gfn = SHINFO_REGION_GPA / PAGE_SIZE
 	};
 
-	struct kvm_xen_hvm_attr cache_destroy = {
+	struct kvm_xen_hvm_attr cache_deactivate = {
 		.type = KVM_XEN_ATTR_TYPE_SHARED_INFO,
-		.u.shared_info.gfn = GPA_INVALID
+		.u.shared_info.gfn = KVM_XEN_INVALID_GFN
 	};
 
 	for (;;) {
-		__vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_init);
-		__vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_destroy);
+		__vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_activate);
+		__vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_deactivate);
 		pthread_testcancel();
 	}