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[3/3] i386: Sanity check CPU model feature sets

Message ID 20210201225404.3941395-4-ehabkost@redhat.com
State New
Headers show
Series i386: Ensure feature names are always defined | expand

Commit Message

Eduardo Habkost Feb. 1, 2021, 10:54 p.m. UTC 
All CPU models must refer only to features that have their names
defined in feature_word_info[].feat_names, otherwise error
reporting and query-cpu-model-expansion will break.

Validate CPU feature flags in x86_cpudef_validate(), we can catch
mistakes more easily.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 target/i386/cpu.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
diff mbox series

Patch

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 6285fb00eb8..3c066738e82 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5435,12 +5435,27 @@  static void x86_register_cpu_model_type(const char *name, X86CPUModel *model)
 static void x86_cpudef_validate(X86CPUDefinition *def)
 {
 #ifndef NDEBUG
+    FeatureWord w;
+    int bitnr;
+
     /* AMD aliases are handled at runtime based on CPUID vendor, so
      * they shouldn't be set on the CPU model table.
      */
     assert(!(def->features[FEAT_8000_0001_EDX] & CPUID_EXT2_AMD_ALIASES));
     /* catch mistakes instead of silently truncating model_id when too long */
     assert(def->model_id && strlen(def->model_id) <= 48);
+
+    /*
+     * CPU models must enable only features with valid names, otherwise
+     * error reporting and query-cpu-model-expansion can't work correctly.
+     */
+    for (w = 0; w < FEATURE_WORDS; w++) {
+        for (bitnr = 0; bitnr < 64; bitnr++) {
+            uint64_t mask = (1ULL << bitnr);
+            assert(!(def->features[w] & mask) ||
+                   feature_word_info[w].feat_names[bitnr]);
+        }
+    }
 #endif
 }