[RFC PATCH 6/7] xl: report per-CPU cache occupancy up to libxl

[Dario Faggioli <dario.faggioli@citrix.com>]

Now that the functionallity is wired, from within Xen
up to libxl, use that to implement a new mode for
`xl psr-cmt-show', by means of the '-c' switch.

With some pCPUs attached to CMT, the output looks as
follows:

  [root@redbrick ~]# xl psr-cmt-show -c cache_occupancy
  Socket 0:      46080 KB Total L3 Cache Size
   CPU 0:         936 KB
   CPU 1:          72 KB
   CPU 3:           0 KB
  Socket 1:      46080 KB Total L3 Cache Size
   CPU 36:         144 KB
   CPU 48:           0 KB
  Socket 2:      46080 KB Total L3 Cache Size
   CPU 74:           0 KB
   CPU 92:           0 KB
  Socket 3:      46080 KB Total L3 Cache Size
   CPU 121:           0 KB

XXX Columns can be aligned better, I know. ;-P

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
---
 tools/libxl/xl_cmdimpl.c  |   88 +++++++++++++++++++++++++++++++++++++++++----
 tools/libxl/xl_cmdtable.c |    2 +
 2 files changed, 82 insertions(+), 8 deletions(-)

diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 394b55d..d314947 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -8098,6 +8098,62 @@ static void psr_cmt_print_domain_info(libxl_dominfo *dominfo,
     printf("\n");
 }
 
+static bool psr_cmt_print_cpu_info(unsigned int cpu)
+{
+    uint32_t l3_occ;
+
+    if (libxl_psr_cmt_get_cpu_cache_occupancy(ctx, cpu, &l3_occ)) {
+        fprintf(stderr, "can't read the cache occupancy for cpu %u\n", cpu);
+        return false;
+    }
+
+    fprintf(stdout, " CPU %u: %11"PRIu32" KB\n", cpu, l3_occ);
+
+    return true;
+}
+
+static int psr_cmt_show_cpus(int cpu)
+{
+    libxl_cputopology *info;
+    int i, rc = 0, nr_cpus = 0;
+    int socket;
+
+    info = libxl_get_cpu_topology(ctx, &nr_cpus);
+    if (info == NULL) {
+        fprintf(stderr, "libxl_get_topologyinfo failed.\n");
+        return 1;
+    }
+
+    socket = -1;
+    for (i = cpu > 0 ? cpu : 0; i <= (cpu > 0 ? cpu : nr_cpus-1); i++) {
+        uint32_t l3_size;
+
+        if (!libxl_psr_cmt_cpu_attached(ctx, i))
+            continue;
+
+        if (socket != info[i].socket) {
+            if (libxl_psr_cmt_get_l3_cache_size(ctx, info[i].socket,
+                                                &l3_size)) {
+                fprintf(stderr, "Failed to get L3 cache size for socket:%d\n",
+                        info[i].socket);
+                rc = 1;
+                goto out;
+            }
+            fprintf(stdout, "Socket %u:%11"PRIu32" KB Total L3 Cache Size\n",
+                    info[i].socket, l3_size);
+            socket = info[i].socket;
+        }
+        if (!psr_cmt_print_cpu_info(i)) {
+            rc = 1;
+            goto out;
+        }
+    }
+
+ out:
+    libxl_cputopology_list_free(info, nr_cpus);
+    return rc;
+}
+
 static int psr_cmt_show(libxl_psr_cmt_type type, uint32_t domid)
 {
     uint32_t i, socketid, nr_sockets, total_rmid;
@@ -8105,11 +8161,6 @@ static int psr_cmt_show(libxl_psr_cmt_type type, uint32_t domid)
     libxl_physinfo info;
     int rc, nr_domains;
 
-    if (!libxl_psr_cmt_enabled(ctx)) {
-        fprintf(stderr, "CMT is disabled in the system\n");
-        return -1;
-    }
-
     if (!libxl_psr_cmt_type_supported(ctx, type)) {
         fprintf(stderr, "Monitor type '%s' is not supported in the system\n",
                 libxl_psr_cmt_type_to_string(type));
@@ -8213,11 +8264,20 @@ int main_psr_cmt_detach(int argc, char **argv)
 int main_psr_cmt_show(int argc, char **argv)
 {
     int opt, ret = 0;
+    bool cpus = false;
     uint32_t domid;
     libxl_psr_cmt_type type;
+    static struct option opts[] = {
+        {"cpus", 0, 0, 'c'},
+        COMMON_LONG_OPTS,
+        {0, 0, 0, 0}
+    };
 
-    SWITCH_FOREACH_OPT(opt, "", NULL, "psr-cmt-show", 1) {
-        /* No options */
+
+    SWITCH_FOREACH_OPT(opt, "c", opts, "psr-cmt-show", 1) {
+        case 'c':
+            cpus = true;
+            break;
     }
 
     if (!strcmp(argv[optind], "cache_occupancy"))
@@ -8231,6 +8291,15 @@ int main_psr_cmt_show(int argc, char **argv)
         return 2;
     }
 
+    if (cpus) {
+        if (type != LIBXL_PSR_CMT_TYPE_CACHE_OCCUPANCY) {
+            fprintf(stderr, "CPU monitoring supported for cache only\n");
+            return -1;
+        }
+        ret = psr_cmt_show_cpus(-1);
+        return ret;
+    }
+
     if (optind + 1 >= argc)
         domid = INVALID_DOMID;
     else if (optind + 1 == argc - 1)
@@ -8240,6 +8309,11 @@ int main_psr_cmt_show(int argc, char **argv)
         return 2;
     }
 
+    if (!libxl_psr_cmt_enabled(ctx)) {
+        fprintf(stderr, "CMT is disabled in the system\n");
+        return -1;
+    }
+
     ret = psr_cmt_show(type, domid);
 
     return ret;
diff --git a/tools/libxl/xl_cmdtable.c b/tools/libxl/xl_cmdtable.c
index 9284887..5bbe406 100644
--- a/tools/libxl/xl_cmdtable.c
+++ b/tools/libxl/xl_cmdtable.c
@@ -537,7 +537,7 @@ struct cmd_spec cmd_table[] = {
     { "psr-cmt-show",
       &main_psr_cmt_show, 0, 1,
       "Show Cache Monitoring Technology information",
-      "<PSR-CMT-Type> <Domain>",
+      "<PSR-CMT-Type> [-c | <Domain>]",
       "Available monitor types:\n"
       "\"cache_occupancy\":         Show L3 cache occupancy(KB)\n"
       "\"total_mem_bandwidth\":     Show total memory bandwidth(KB/s)\n"