From: Daniel P. Berrangé <berrange@redhat.com>
Date: Fri, 13 Mar 2020 16:43:26 +0000 (+0000)
Subject: qemu: fix detection of vCPU pids when multiple dies are present
X-Git-Tag: v6.2.0-rc1~174
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8b789c6574454863acbd2511fc2094d1e63e8154;p=thirdparty%2Flibvirt.git

qemu: fix detection of vCPU pids when multiple dies are present

The logic for querying hotpluggable CPUs needs to sort the list
of CPUs returned by QEMU. Unfortunately our sorting method failed
to use the die_id field, so CPUs were not correctly sorted.

This is seen when configuring a guest with partially populated
CPUs

  <vcpu placement='static' current='1'>16</vcpu>
  <cpu...>
    <topology sockets='4' dies='2' cores='1' threads='2'/>
  </cpu>

Then trying to start it would fail:

  # virsh -c qemu:///system start demo
  error: Failed to start domain demo
  error: internal error: qemu didn't report thread id for vcpu '0'

Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 34eb094528..68b1da2958 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -13644,8 +13644,14 @@ qemuDomainRefreshVcpuInfo(virQEMUDriverPtr driver,
         }
 
         if (validTIDs)
-            VIR_DEBUG("vCPU[%zu] PID %llu is valid",
-                      i, (unsigned long long)info[i].tid);
+            VIR_DEBUG("vCPU[%zu] PID %llu is valid "
+                      "(node=%d socket=%d die=%d core=%d thread=%d)",
+                      i, (unsigned long long)info[i].tid,
+                      info[i].node_id,
+                      info[i].socket_id,
+                      info[i].die_id,
+                      info[i].core_id,
+                      info[i].thread_id);
     }
 
     VIR_DEBUG("Extracting vCPU information validTIDs=%d", validTIDs);
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index e3d621f038..017b818f73 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -1615,6 +1615,7 @@ qemuMonitorCPUInfoClear(qemuMonitorCPUInfoPtr cpus,
         cpus[i].id = 0;
         cpus[i].qemu_id = -1;
         cpus[i].socket_id = -1;
+        cpus[i].die_id = -1;
         cpus[i].core_id = -1;
         cpus[i].thread_id = -1;
         cpus[i].node_id = -1;
@@ -1770,6 +1771,7 @@ qemuMonitorGetCPUInfoHotplug(struct qemuMonitorQueryHotpluggableCpusEntry *hotpl
         vcpus[mastervcpu].hotpluggable = !!hotplugvcpus[i].alias ||
                                          !vcpus[mastervcpu].online;
         vcpus[mastervcpu].socket_id = hotplugvcpus[i].socket_id;
+        vcpus[mastervcpu].die_id = hotplugvcpus[i].die_id;
         vcpus[mastervcpu].core_id = hotplugvcpus[i].core_id;
         vcpus[mastervcpu].thread_id = hotplugvcpus[i].thread_id;
         vcpus[mastervcpu].node_id = hotplugvcpus[i].node_id;
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 6ccea909e9..be4195e734 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -561,6 +561,7 @@ struct qemuMonitorQueryHotpluggableCpusEntry {
     /* topology information -1 if qemu didn't report given parameter */
     int node_id;
     int socket_id;
+    int die_id;
     int core_id;
     int thread_id;
 
@@ -583,6 +584,7 @@ struct _qemuMonitorCPUInfo {
     /* topology info for hotplug purposes. Hotplug of given vcpu impossible if
      * all entries are -1 */
     int socket_id;
+    int die_id;
     int core_id;
     int thread_id;
     int node_id;
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 3eac80c060..8e1e81ee06 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -8560,11 +8560,13 @@ qemuMonitorJSONProcessHotpluggableCpusReply(virJSONValuePtr vcpu,
 
     entry->node_id = -1;
     entry->socket_id = -1;
+    entry->die_id = -1;
     entry->core_id = -1;
     entry->thread_id = -1;
 
     ignore_value(virJSONValueObjectGetNumberInt(props, "node-id", &entry->node_id));
     ignore_value(virJSONValueObjectGetNumberInt(props, "socket-id", &entry->socket_id));
+    ignore_value(virJSONValueObjectGetNumberInt(props, "die-id", &entry->die_id));
     ignore_value(virJSONValueObjectGetNumberInt(props, "core-id", &entry->core_id));
     ignore_value(virJSONValueObjectGetNumberInt(props, "thread-id", &entry->thread_id));
 
@@ -8599,6 +8601,9 @@ qemuMonitorQueryHotpluggableCpusEntrySort(const void *p1,
     if (a->socket_id != b->socket_id)
         return a->socket_id - b->socket_id;
 
+    if (a->die_id != b->die_id)
+        return a->die_id - b->die_id;
+
     if (a->core_id != b->core_id)
         return a->core_id - b->core_id;