KVM: selftests: Stop assuming stats are contiguous in kvm_binary_stat…

…s_test

Remove the assumption from kvm_binary_stats_test that all stats are
laid out contiguously in memory. The current stats in KVM are
contiguously laid out in memory, but that may change in the future and
the ABI specifically allows holes in the stats data (since each stat
exposes its own offset).

While here drop the check that each stats' offset is less than
size_data, as that is now always true by construction.

Link: https://lore.kernel.org/kvm/20221208193857.4090582-9-dmatlack@google.com/
Fixes: 0b45d58 ("KVM: selftests: Add selftest for KVM statistics data binary interface")
Signed-off-by: Jing Zhang <jingzhangos@google.com>
[dmatlack: Re-worded the commit message.]
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20230117222707.3949974-1-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

tools/testing/selftests/kvm/kvm_binary_stats_test.c

@@ -134,7 +134,7 @@ static void stats_test(int stats_fd)
 				    "Bucket size of stats (%s) is not zero",
 				    pdesc->name);
 		}
-		size_data += pdesc->size * sizeof(*stats_data);
+		size_data = max(size_data, pdesc->offset + pdesc->size * sizeof(*stats_data));
 	}
 
 	/*
@@ -149,14 +149,6 @@ static void stats_test(int stats_fd)
 	TEST_ASSERT(size_data >= header.num_desc * sizeof(*stats_data),
 		    "Data size is not correct");
 
-	/* Check stats offset */
-	for (i = 0; i < header.num_desc; ++i) {
-		pdesc = get_stats_descriptor(stats_desc, i, &header);
-		TEST_ASSERT(pdesc->offset < size_data,
-			    "Invalid offset (%u) for stats: %s",
-			    pdesc->offset, pdesc->name);
-	}
-
 	/* Allocate memory for stats data */
 	stats_data = malloc(size_data);
 	TEST_ASSERT(stats_data, "Allocate memory for stats data");