[PATCH 0/2] monitor, kvm: support for boolean statistics

[PATCH 0/2] monitor, kvm: support for boolean statistics

[Paolo Bonzini]

Some statistics exported by KVM only ever have a 0 or 1 value, and Linux has
grown the ability to mark them as such.  Bring it over to the new statistics
subsystem of QEMU: they will be presented to QAPI clients as JSON booleans, and
in HMP as "yes"/"no".

(This was proposed in the context of the Libvirt query-stats GSoC project,
and support will be in Linux 5.19-rc7).

Paolo

Paolo Bonzini (2):
  monitor: add support for boolean statistics
  kvm: add support for boolean statistics

 accel/kvm/kvm-all.c       | 10 +++++++++-
 linux-headers/linux/kvm.h |  1 +
 monitor/hmp-cmds.c        |  2 ++
 qapi/stats.json           |  4 +++-
 4 files changed, 15 insertions(+), 2 deletions(-)

-- 
2.36.1

[PATCH 1/2] monitor: add support for boolean statistics

[Paolo Bonzini]

The next version of Linux will introduce boolean statistics, which
can only have 0 or 1 values.  Support them in the schema and in
the HMP command.

Suggested-by: Amneesh Singh <natto@weirdnatto.in>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 monitor/hmp-cmds.c | 2 ++
 qapi/stats.json    | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index ca98df0495..e8d6963722 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -2337,6 +2337,8 @@ static void print_stats_results(Monitor *mon, StatsTarget target,
 
         if (stats_value->type == QTYPE_QNUM) {
             monitor_printf(mon, ": %" PRId64 "\n", stats_value->u.scalar);
+        } else if (stats_value->type == QTYPE_QBOOL) {
+            monitor_printf(mon, ": %s\n", stats_value->u.boolean ? "yes" : "no");
         } else if (stats_value->type == QTYPE_QLIST) {
             uint64List *list;
             int i;
diff --git a/qapi/stats.json b/qapi/stats.json
index 2f8bfe8fdb..cb6456c67a 100644
--- a/qapi/stats.json
+++ b/qapi/stats.json
@@ -38,11 +38,12 @@
 # @bytes: stat reported in bytes.
 # @seconds: stat reported in seconds.
 # @cycles: stat reported in clock cycles.
+# @cycles: stat is a boolean value.
 #
 # Since: 7.1
 ##
 { 'enum' : 'StatsUnit',
-  'data' : [ 'bytes', 'seconds', 'cycles' ] }
+  'data' : [ 'bytes', 'seconds', 'cycles', 'boolean' ] }
 
 ##
 # @StatsProvider:
@@ -123,6 +124,7 @@
 ##
 { 'alternate': 'StatsValue',
   'data': { 'scalar': 'uint64',
+            'boolean': 'bool',
             'list': [ 'uint64' ] } }
 
 ##
-- 
2.36.1

[PATCH 2/2] kvm: add support for boolean statistics

[Paolo Bonzini]

The next version of Linux will introduce boolean statistics, which
can only have 0 or 1 values.  Convert them to the new QAPI fields
added in the previous commit.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 accel/kvm/kvm-all.c       | 10 +++++++++-
 linux-headers/linux/kvm.h |  1 +
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index ed8b6b896e..3a2677d065 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -3743,6 +3743,7 @@ static StatsList *add_kvmstat_entry(struct kvm_stats_desc *pdesc,
     case KVM_STATS_UNIT_BYTES:
     case KVM_STATS_UNIT_CYCLES:
     case KVM_STATS_UNIT_SECONDS:
+    case KVM_STATS_UNIT_BOOLEAN:
         break;
     default:
         return stats_list;
@@ -3761,7 +3762,10 @@ static StatsList *add_kvmstat_entry(struct kvm_stats_desc *pdesc,
     stats->name = g_strdup(pdesc->name);
     stats->value = g_new0(StatsValue, 1);;
 
-    if (pdesc->size == 1) {
+    if ((pdesc->flags & KVM_STATS_UNIT_MASK) == KVM_STATS_UNIT_BOOLEAN) {
+        stats->value->u.boolean = *stats_data;
+        stats->value->type = QTYPE_QBOOL;
+    } else if (pdesc->size == 1) {
         stats->value->u.scalar = *stats_data;
         stats->value->type = QTYPE_QNUM;
     } else {
@@ -3809,6 +3813,10 @@ static StatsSchemaValueList *add_kvmschema_entry(struct kvm_stats_desc *pdesc,
     switch (pdesc->flags & KVM_STATS_UNIT_MASK) {
     case KVM_STATS_UNIT_NONE:
         break;
+    case KVM_STATS_UNIT_BOOLEAN:
+        schema_entry->value->has_unit = true;
+        schema_entry->value->unit = STATS_UNIT_BOOLEAN;
+        break;
     case KVM_STATS_UNIT_BYTES:
         schema_entry->value->has_unit = true;
         schema_entry->value->unit = STATS_UNIT_BYTES;
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 0d05d02ee4..f089349149 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -2031,6 +2031,7 @@ struct kvm_stats_header {
 #define KVM_STATS_UNIT_BYTES		(0x1 << KVM_STATS_UNIT_SHIFT)
 #define KVM_STATS_UNIT_SECONDS		(0x2 << KVM_STATS_UNIT_SHIFT)
 #define KVM_STATS_UNIT_CYCLES		(0x3 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_BOOLEAN		(0x4 << KVM_STATS_UNIT_SHIFT)
 #define KVM_STATS_UNIT_MAX		KVM_STATS_UNIT_CYCLES
 
 #define KVM_STATS_BASE_SHIFT		8
-- 
2.36.1