lwp: adding support for AMD lightweight profiling

diff -r c64dcc4d2eca -r b57ee5edd292 tools/libxc/xc_cpuid_x86.c
@@ -30,7 +30,8 @@
 #define set_bit(idx, dst)   ((dst) |= (1u << ((idx) & 31)))
 
 #define DEF_MAX_BASE 0x0000000du
-#define DEF_MAX_EXT  0x80000008u
+#define DEF_MAX_INTELEXT  0x80000008u
+#define DEF_MAX_AMDEXT    0x8000001cu
 
 static int hypervisor_is_64bit(xc_interface *xch)
 {

@@ -87,6 +88,11 @@
         regs[0] = regs[1] = regs[2] = 0;
         break;
 
+    case 0x80000000:
+        if ( regs[0] > DEF_MAX_AMDEXT )
+            regs[0] = DEF_MAX_AMDEXT;
+        break;
+
     case 0x80000001: {
         int is_64bit = hypervisor_is_64bit(xch) && is_pae;
 

@@ -104,7 +110,8 @@
                     bitmaskof(X86_FEATURE_3DNOWPREFETCH) |
                     bitmaskof(X86_FEATURE_XOP) |
                     bitmaskof(X86_FEATURE_FMA4) |
-                    bitmaskof(X86_FEATURE_TBM));
+                    bitmaskof(X86_FEATURE_TBM) |
+                    bitmaskof(X86_FEATURE_LWP));
         regs[3] &= (0x0183f3ff | /* features shared with 0x00000001:EDX */
                     (is_pae ? bitmaskof(X86_FEATURE_NX) : 0) |
                     (is_64bit ? bitmaskof(X86_FEATURE_LM) : 0) |

@@ -144,6 +151,11 @@
         regs[3] &= 0x3ffu;
         break;
 
+    case 0x80000000:
+        if ( regs[0] > DEF_MAX_INTELEXT )
+            regs[0] = DEF_MAX_INTELEXT;
+        break;
+
     case 0x80000001: {
         int is_64bit = hypervisor_is_64bit(xch) && is_pae;
 

@@ -305,8 +317,7 @@
         break;
 
     case 0x80000000:
-        if ( regs[0] > DEF_MAX_EXT )
-            regs[0] = DEF_MAX_EXT;
+        /* Passthrough to cpu vendor specific functions */
         break;
 
     case 0x80000001:

@@ -335,6 +346,7 @@
     case 0x80000004: /* ... continued         */
     case 0x80000005: /* AMD L1 cache/TLB info (dumped by Intel policy) */
     case 0x80000006: /* AMD L2/3 cache/TLB info ; Intel L2 cache features */
+    case 0x8000001c: /* AMD lightweight profiling */
         break;
 
     default:

@@ -507,13 +519,19 @@
 {
     unsigned int input[2] = { 0, 0 }, regs[4];
     unsigned int base_max, ext_max;
+    char brand[13];
     int rc;
 
     cpuid(input, regs);
     base_max = (regs[0] <= DEF_MAX_BASE) ? regs[0] : DEF_MAX_BASE;
     input[0] = 0x80000000;
     cpuid(input, regs);
-    ext_max = (regs[0] <= DEF_MAX_EXT) ? regs[0] : DEF_MAX_EXT;
+
+    xc_cpuid_brand_get(brand);
+    if ( strstr(brand, "AMD") )
+        ext_max = (regs[0] <= DEF_MAX_AMDEXT) ? regs[0] : DEF_MAX_AMDEXT;
+    else
+        ext_max = (regs[0] <= DEF_MAX_INTELEXT) ? regs[0] : DEF_MAX_INTELEXT;
 
     input[0] = 0;
     input[1] = XEN_CPUID_INPUT_UNUSED;