[Xen-changelog] [xen staging-4.6] x86/AMD: distinguish compute units from hyper-threads

[patchbot@xxxxxxx]

commit cf7d9d1f3a04b6626e00c0683d414be933b9d011
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Mon Jul 30 14:19:05 2018 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Jul 30 14:19:05 2018 +0200

    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@xxxxxxxx>
    Reviewed-by: Brian Woods <brian.woods@xxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    master commit: 9429b07a0af7f92a5f25e4068e11db881e157495
    master date: 2018-07-19 09:42:42 +0200
---
 xen/arch/x86/cpu/amd.c | 16 +++++++++++-----
 xen/arch/x86/smpboot.c | 32 ++++++++++++++++++++------------
 2 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index efd943ae13..9ae51e487c 100644
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -412,17 +412,23 @@ static void __devinit 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 __devinit init_amd(struct cpuinfo_x86 *c)
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 57ccd0febe..66d794b19c 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -253,33 +253,41 @@ 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 )
     {
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.6

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