From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 30 Jul 2018 12:10:30 +0000 (+0200)
Subject: x86/AMD: distinguish compute units from hyper-threads
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=e90e2431a4aee843db49db9a3ac7ee0d9e1bf8f0;p=xen.git

x86/AMD: distinguish compute units from hyper-threads

Fam17 replaces CUs by HTs, which we should reflect accordingly, even if
the difference is not very big. The most relevant change (requiring some
code restructuring) is that the topoext feature no longer means there is
a valid CU ID.

Take the opportunity and convert wrongly plain int variables in
set_cpu_sibling_map() to unsigned int.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Brian Woods <brian.woods@amd.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 9429b07a0af7f92a5f25e4068e11db881e157495
master date: 2018-07-19 09:42:42 +0200
---

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index 5fc2b1dcab..bc16f7e632 100644
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -502,17 +502,23 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
                 u32 eax, ebx, ecx, edx;
 
                 cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
-                c->compute_unit_id = ebx & 0xFF;
                 c->x86_num_siblings = ((ebx >> 8) & 0x3) + 1;
+
+                if (c->x86 < 0x17)
+                        c->compute_unit_id = ebx & 0xFF;
+                else {
+                        c->cpu_core_id = ebx & 0xFF;
+                        c->x86_max_cores /= c->x86_num_siblings;
+                }
         }
         
         if (opt_cpu_info)
                 printk("CPU %d(%d) -> Processor %d, %s %d\n",
                        cpu, c->x86_max_cores, c->phys_proc_id,
-                       cpu_has(c, X86_FEATURE_TOPOEXT) ? "Compute Unit" : 
-                                                         "Core",
-                       cpu_has(c, X86_FEATURE_TOPOEXT) ? c->compute_unit_id :
-                                                         c->cpu_core_id);
+                       c->compute_unit_id != INVALID_CUID ? "Compute Unit"
+                                                          : "Core",
+                       c->compute_unit_id != INVALID_CUID ? c->compute_unit_id
+                                                          : c->cpu_core_id);
 }
 
 static void early_init_amd(struct cpuinfo_x86 *c)
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 97804d3b4d..7874e694ed 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -219,33 +219,41 @@ static void link_thread_siblings(int cpu1, int cpu2)
     cpumask_set_cpu(cpu2, per_cpu(cpu_core_mask, cpu1));
 }
 
-static void set_cpu_sibling_map(int cpu)
+static void set_cpu_sibling_map(unsigned int cpu)
 {
-    int i;
+    unsigned int i;
     struct cpuinfo_x86 *c = cpu_data;
 
     cpumask_set_cpu(cpu, &cpu_sibling_setup_map);
 
     cpumask_set_cpu(cpu, socket_cpumask[cpu_to_socket(cpu)]);
+    cpumask_set_cpu(cpu, per_cpu(cpu_core_mask, cpu));
+    cpumask_set_cpu(cpu, per_cpu(cpu_sibling_mask, cpu));
 
     if ( c[cpu].x86_num_siblings > 1 )
     {
         for_each_cpu ( i, &cpu_sibling_setup_map )
         {
-            if ( cpu_has(c, X86_FEATURE_TOPOEXT) ) {
-                if ( (c[cpu].phys_proc_id == c[i].phys_proc_id) &&
-                     (c[cpu].compute_unit_id == c[i].compute_unit_id) )
+            if ( cpu == i || c[cpu].phys_proc_id != c[i].phys_proc_id )
+                continue;
+            if ( c[cpu].compute_unit_id != INVALID_CUID &&
+                 c[i].compute_unit_id != INVALID_CUID )
+            {
+                if ( c[cpu].compute_unit_id == c[i].compute_unit_id )
+                    link_thread_siblings(cpu, i);
+            }
+            else if ( c[cpu].cpu_core_id != XEN_INVALID_CORE_ID &&
+                      c[i].cpu_core_id != XEN_INVALID_CORE_ID )
+            {
+                if ( c[cpu].cpu_core_id == c[i].cpu_core_id )
                     link_thread_siblings(cpu, i);
-            } else if ( (c[cpu].phys_proc_id == c[i].phys_proc_id) &&
-                        (c[cpu].cpu_core_id == c[i].cpu_core_id) ) {
-                link_thread_siblings(cpu, i);
             }
+            else
+                printk(XENLOG_WARNING
+                       "CPU%u: unclear relationship with CPU%u\n",
+                       cpu, i);
         }
     }
-    else
-    {
-        cpumask_set_cpu(cpu, per_cpu(cpu_sibling_mask, cpu));
-    }
 
     if ( c[cpu].x86_max_cores == 1 )
     {