From ec480dc43848aeb20abc82e12cb673f97e6a856d Mon Sep 17 00:00:00 2001
From: Christophe de Dinechin <dinechin@redhat.com>
Date: Wed, 6 Aug 2025 18:51:14 +0200
Subject: [PATCH] qemu: Respect the JSON schema for hot plug

When hot-plugging CPUs on QEMU, we send a QMP command with JSON
arguments. QEMU 9.2 recently became more strict[1] enforcing the
JSON schema for QMP parameters. As a result, running Kata Containers
with QEMU 9.2 results in a message complaining that the core-id
parameter is expected to be an integer:

```
qmp hotplug cpu, cpuID=cpu-0 socketID=1, error:
QMP command failed:
Invalid parameter type for 'core-id', expected: integer
```

Fix that by changing the core-id, socket-id and thread-id to be
integer values.

[1]: https://github.com/qemu/qemu/commit/be93fd53723cbdca675bd9ed112dae5cabbe1e91

Fixes: #11633

Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>
---
 src/runtime/pkg/govmm/qemu/qmp.go      | 12 +++++-------
 src/runtime/pkg/govmm/qemu/qmp_test.go |  8 ++++----
 src/runtime/virtcontainers/qemu.go     | 16 ++++++++--------
 3 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/src/runtime/pkg/govmm/qemu/qmp.go b/src/runtime/pkg/govmm/qemu/qmp.go
index 3b6e2c7e6b..4eafb66767 100644
--- a/src/runtime/pkg/govmm/qemu/qmp.go
+++ b/src/runtime/pkg/govmm/qemu/qmp.go
@@ -1257,25 +1257,23 @@ func (q *QMP) isDieIDSupported(driver string) bool {
 // node/board the CPU belongs to, coreID is the core number within socket the CPU belongs to, threadID is the
 // thread number within core the CPU belongs to. Note that socketID and threadID are not a requirement for
 // architecures like ppc64le.
-func (q *QMP) ExecuteCPUDeviceAdd(ctx context.Context, driver, cpuID, socketID, dieID, coreID, threadID, romfile string) error {
+func (q *QMP) ExecuteCPUDeviceAdd(ctx context.Context, driver, cpuID string, socketID, dieID, coreID, threadID int, romfile string) error {
 	args := map[string]interface{}{
 		"driver":  driver,
 		"id":      cpuID,
 		"core-id": coreID,
 	}
 
-	if socketID != "" && isSocketIDSupported(driver) {
+	if socketID >= 0 && isSocketIDSupported(driver) {
 		args["socket-id"] = socketID
 	}
 
-	if threadID != "" && isThreadIDSupported(driver) {
+	if threadID >= 0 && isThreadIDSupported(driver) {
 		args["thread-id"] = threadID
 	}
 
-	if q.isDieIDSupported(driver) {
-		if dieID != "" {
-			args["die-id"] = dieID
-		}
+	if dieID >= 0 && q.isDieIDSupported(driver) {
+		args["die-id"] = dieID
 	}
 
 	return q.executeCommand(ctx, "device_add", args, nil)
diff --git a/src/runtime/pkg/govmm/qemu/qmp_test.go b/src/runtime/pkg/govmm/qemu/qmp_test.go
index 06738a40d6..7aeb907e48 100644
--- a/src/runtime/pkg/govmm/qemu/qmp_test.go
+++ b/src/runtime/pkg/govmm/qemu/qmp_test.go
@@ -1140,10 +1140,10 @@ func TestQMPAPVFIOMediatedDeviceAdd(t *testing.T) {
 func TestQMPCPUDeviceAdd(t *testing.T) {
 	drivers := []string{"host-x86_64-cpu", "host-s390x-cpu", "host-powerpc64-cpu"}
 	cpuID := "cpu-0"
-	socketID := "0"
-	dieID := "0"
-	coreID := "1"
-	threadID := "0"
+	socketID := 0
+	dieID := 0
+	coreID := 1
+	threadID := 0
 	for _, d := range drivers {
 		connectedCh := make(chan *QMPVersion)
 		disconnectedCh := make(chan struct{})
diff --git a/src/runtime/virtcontainers/qemu.go b/src/runtime/virtcontainers/qemu.go
index 51a46d2729..0de579c870 100644
--- a/src/runtime/virtcontainers/qemu.go
+++ b/src/runtime/virtcontainers/qemu.go
@@ -2197,20 +2197,20 @@ func (q *qemu) hotplugAddCPUs(amount uint32) (uint32, error) {
 		// CPU type, i.e host-x86_64-cpu
 		driver := hc.Type
 		cpuID := fmt.Sprintf("cpu-%d", len(q.state.HotpluggedVCPUs))
-		socketID := fmt.Sprintf("%d", hc.Properties.Socket)
-		dieID := fmt.Sprintf("%d", hc.Properties.Die)
-		coreID := fmt.Sprintf("%d", hc.Properties.Core)
-		threadID := fmt.Sprintf("%d", hc.Properties.Thread)
+		socketID := hc.Properties.Socket
+		dieID := hc.Properties.Die
+		coreID := hc.Properties.Core
+		threadID := hc.Properties.Thread
 
 		// If CPU type is IBM pSeries, Z or arm virt, we do not set socketID and threadID
 		if machine.Type == "pseries" || machine.Type == QemuCCWVirtio || machine.Type == "virt" {
-			socketID = ""
-			threadID = ""
-			dieID = ""
+			socketID = -1
+			threadID = -1
+			dieID = -1
 		}
 
 		if err := q.qmpMonitorCh.qmp.ExecuteCPUDeviceAdd(q.qmpMonitorCh.ctx, driver, cpuID, socketID, dieID, coreID, threadID, romFile); err != nil {
-			q.Logger().WithField("hotplug", "cpu").Warnf("qmp hotplug cpu, cpuID=%s socketID=%s, error: %v", cpuID, socketID, err)
+			q.Logger().WithField("hotplug", "cpu").Warnf("qmp hotplug cpu, cpuID=%s socketID=%d, error: %v", cpuID, socketID, err)
 			// don't fail, let's try with other CPU
 			continue
 		}