From: Roger Pau Monné <roger.pau@citrix.com>
Date: Thu, 2 May 2024 11:49:22 +0000 (+0100)
Subject: tools/xen-cpuid: Use automatically generated feature names
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=bbb5c171d730eb524d21c7348726f06e95f6db19;p=people%2Faperard%2Fxen-unstable.git

tools/xen-cpuid: Use automatically generated feature names

Have gen-cpuid.py write out INIT_FEATURE_VAL_TO_NAME, derived from the same
data source as INIT_FEATURE_NAME_TO_VAL, although both aliases of common_1d
are needed.

In xen-cpuid.c, sanity check at build time that leaf_info[] and
feature_names[] are of sensible length.

As dump_leaf() rendered missing names as numbers, always dump leaves even if
we don't have the leaf name.  This conversion was argumably missed in commit
59afdb8a81d6 ("tools/misc: Tweak reserved bit handling for xen-cpuid").

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
---

diff --git a/tools/misc/xen-cpuid.c b/tools/misc/xen-cpuid.c
index 6ee835b229..51009683da 100644
--- a/tools/misc/xen-cpuid.c
+++ b/tools/misc/xen-cpuid.c
@@ -11,6 +11,7 @@
 #include <xenguest.h>
 
 #include <xen-tools/common-macros.h>
+#include <xen/lib/x86/cpuid-autogen.h>
 
 static uint32_t nr_features;
 
@@ -291,6 +292,8 @@ static const struct {
 
 #define COL_ALIGN "24"
 
+static const char *const feature_names[] = INIT_FEATURE_VAL_TO_NAME;
+
 static const char *const fs_names[] = {
     [XEN_SYSCTL_cpu_featureset_raw]     = "Raw",
     [XEN_SYSCTL_cpu_featureset_host]    = "Host",
@@ -304,12 +307,6 @@ static void dump_leaf(uint32_t leaf, const char *const *strs)
 {
     unsigned i;
 
-    if ( !strs )
-    {
-        printf(" ???");
-        return;
-    }
-
     for ( i = 0; i < 32; ++i )
         if ( leaf & (1u << i) )
         {
@@ -327,6 +324,10 @@ static void decode_featureset(const uint32_t *features,
 {
     unsigned int i;
 
+    /* If this trips, you probably need to extend leaf_info[] above. */
+    BUILD_BUG_ON(ARRAY_SIZE(leaf_info) != FEATURESET_NR_ENTRIES);
+    BUILD_BUG_ON(ARRAY_SIZE(feature_names) != FEATURESET_NR_ENTRIES * 32);
+
     printf("%-"COL_ALIGN"s        ", name);
     for ( i = 0; i < length; ++i )
         printf("%08x%c", features[i],
@@ -338,8 +339,7 @@ static void decode_featureset(const uint32_t *features,
     for ( i = 0; i < length && i < ARRAY_SIZE(leaf_info); ++i )
     {
         printf("  [%02u] %-"COL_ALIGN"s", i, leaf_info[i].name ?: "<UNKNOWN>");
-        if ( leaf_info[i].name )
-            dump_leaf(features[i], leaf_info[i].strs);
+        dump_leaf(features[i], &feature_names[i * 32]);
         printf("\n");
     }
 }
diff --git a/xen/tools/gen-cpuid.py b/xen/tools/gen-cpuid.py
index 79d7f5c8e1..601eec6089 100755
--- a/xen/tools/gen-cpuid.py
+++ b/xen/tools/gen-cpuid.py
@@ -470,6 +470,35 @@ def write_results(state):
     state.output.write(
 """}
 
+""")
+
+    state.output.write(
+"""
+#define INIT_FEATURE_VAL_TO_NAME { \\
+""")
+
+    for name, bit in sorted(state.values.items()):
+        state.output.write(
+            '    [%s] = "%s",\\\n' % (bit, name)
+            )
+
+        # Add the other alias for 1d/e1d common bits.  64 is the difference
+        # between 1d and e1d.
+        if bit in state.common_1d:
+            state.output.write(
+                '    [%s] = "%s",\\\n' % (64 + bit, name)
+            )
+
+    # Pad to an exact multiple of FEATURESET_SIZE if necessary
+    pad_feat = state.nr_entries * 32 - 1
+    if not state.names.get(pad_feat):
+        state.output.write(
+            '    [%s] = NULL,\\\n' % (pad_feat, )
+        )
+
+    state.output.write(
+"""}
+
 """)
 
     for idx, text in enumerate(state.bitfields):