Attachment 580182 Details for Bug 671510 – Modified code to differentiate between XenServer and Hyper-V

Modified code to differentiate between XenServer and Hyper-V

xenvmm.patch (text/plain), 1.50 KB, created by Valentine Sinitsyn on 2012-04-25 15:02:56 UTC

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Creator: Valentine Sinitsyn

Created: 2012-04-25 15:02:56 UTC

Size: 1.50 KB

patch

obsolete

>--- a/virt-what-cpuid-helper.c
>+++ b/virt-what-cpuid-helper.c
>@@ -39,29 +39,40 @@ cpuid (unsigned int eax, char *sig)
>   return eax;
> }
> 
>+#define MIN(x,y) ((x) <= (y) ? (x) : (y))
> static void
> cpu_sig (void)
> {
>   char sig[13];
>   unsigned int base = 0x40000000, leaf = base;
>   unsigned int max_entries;
>+  unsigned int xen = 0;
> 
>   memset (sig, 0, sizeof sig);
>   max_entries = cpuid (leaf, sig);
>-  puts (sig);
> 
>   /* Most hypervisors only have information in leaf 0x40000000, but
>    * upstream Xen contains further leaf entries (in particular when
>    * used with Viridian [HyperV] extensions).  CPUID is supposed to
>    * return the maximum leaf offset in %eax, so that's what we use,
>    * but only if it looks sensible.
>+   *
>+   * The problem is that (at leat) for some Xen releases, this number
>+   * doesn't look sensible. So we need to implement more sopisticated
>+   * logic in order to diffirentiate between Xen and Hyper-V.
>    */
>-  if (max_entries > 3 && max_entries < 0x10000) {
>-    for (leaf = base + 0x100; leaf <= base + max_entries; leaf += 0x100) {
>+  if (!strcmp("Microsoft Hv", sig) && max_entries != 0) {
>+    for (leaf = base + 0x100; leaf < base + MIN(max_entries, 0x10000); leaf += 0x100) {
>       memset (sig, 0, sizeof sig);
>       cpuid (leaf, sig);
>-      puts (sig);
>+      if (!strcmp("XenVMMXenVMM", sig)) {
>+        xen = 1;
>+        break;
>+      }
>     }
>+    puts(xen ? "XenVMMXenVMM" : "Microsoft Hv");
>+  } else {
>+    puts(sig);
>   }
> }
>

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Attachments on bug 671510: 580182