[PATCH 093/103] qemuBuildVsockCommandLine: Generate via JSON

[Peter Krempa]

Build the properties of 'vhost-vsock' device via JSON. In comparison to
previous similar refactors this also modifies the hotplug code to attach
the vhost fd handle explicitly rather than using
'qemuMonitorAddDeviceWithFd'.

The properties of vhost-vsock have the following types according to
QEMU:

  guest-cid=<uint64>     -  (default: 0)
  vhostfd=<str>

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/qemu/qemu_command.c | 36 ++++++++++++++++++++----------------
 src/qemu/qemu_command.h | 12 +++++-------
 src/qemu/qemu_hotplug.c | 21 ++++++++++++++++-----
 3 files changed, 41 insertions(+), 28 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index a92bdd62f9..c566ab7bd5 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -10553,27 +10553,30 @@ qemuBuildSeccompSandboxCommandLine(virCommand *cmd,
 }


-char *
-qemuBuildVsockDevStr(virDomainDef *def,
-                     virDomainVsockDef *vsock,
-                     virQEMUCaps *qemuCaps,
-                     const char *fdprefix)
+virJSONValue *
+qemuBuildVsockDevProps(virDomainDef *def,
+                       virDomainVsockDef *vsock,
+                       virQEMUCaps *qemuCaps,
+                       const char *fdprefix)
 {
     qemuDomainVsockPrivate *priv = (qemuDomainVsockPrivate *)vsock->privateData;
-    g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER;
+    g_autoptr(virJSONValue) props = NULL;
+    g_autofree char *vhostfd = g_strdup_printf("%s%u", fdprefix, priv->vhostfd);

-    if (qemuBuildVirtioDevStr(&buf, qemuCaps, VIR_DOMAIN_DEVICE_VSOCK, vsock) < 0) {
+    if (!(props = qemuBuildVirtioDevProps(VIR_DOMAIN_DEVICE_VSOCK, vsock, qemuCaps)))
         return NULL;
-    }

-    virBufferAsprintf(&buf, ",id=%s", vsock->info.alias);
-    virBufferAsprintf(&buf, ",guest-cid=%u", vsock->guest_cid);
-    virBufferAsprintf(&buf, ",vhostfd=%s%u", fdprefix, priv->vhostfd);
+    if (virJSONValueObjectAdd(props,
+                              "s:id", vsock->info.alias,
+                              "u:guest-cid", vsock->guest_cid,
+                              "s:vhostfd", vhostfd,
+                              NULL) < 0)
+        return NULL;

-    if (qemuBuildDeviceAddressStr(&buf, def, &vsock->info) < 0)
+    if (qemuBuildDeviceAddressProps(props, def, &vsock->info) < 0)
         return NULL;

-    return virBufferContentAndReset(&buf);
+    return g_steal_pointer(&props);
 }


@@ -10584,9 +10587,9 @@ qemuBuildVsockCommandLine(virCommand *cmd,
                           virQEMUCaps *qemuCaps)
 {
     qemuDomainVsockPrivate *priv = (qemuDomainVsockPrivate *)vsock->privateData;
-    g_autofree char *devstr = NULL;
+    g_autoptr(virJSONValue) devprops = NULL;

-    if (!(devstr = qemuBuildVsockDevStr(def, vsock, qemuCaps, "")))
+    if (!(devprops = qemuBuildVsockDevProps(def, vsock, qemuCaps, "")))
         return -1;

     virCommandPassFD(cmd, priv->vhostfd, VIR_COMMAND_PASS_FD_CLOSE_PARENT);
@@ -10595,7 +10598,8 @@ qemuBuildVsockCommandLine(virCommand *cmd,
     if (qemuCommandAddExtDevice(cmd, &vsock->info, qemuCaps) < 0)
         return -1;

-    virCommandAddArgList(cmd, "-device", devstr, NULL);
+    if (qemuBuildDeviceCommandlineFromJSON(cmd, devprops, qemuCaps) < 0)
+        return -1;

     return 0;
 }
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index 2a87a8a929..56999b7424 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -248,13 +248,11 @@ virJSONValue *
 qemuBuildInputUSBDevProps(const virDomainDef *def,
                           virDomainInputDef *dev);

-char *
-qemuBuildVsockDevStr(virDomainDef *def,
-                     virDomainVsockDef *vsock,
-                     virQEMUCaps *qemuCaps,
-                     const char *fdprefix)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
-    ATTRIBUTE_NONNULL(4);
+virJSONValue *
+qemuBuildVsockDevProps(virDomainDef *def,
+                       virDomainVsockDef *vsock,
+                       virQEMUCaps *qemuCaps,
+                       const char *fdprefix);

 /* this function is exported so that tests can mock the FDs */
 int
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 1e91fb393e..b9937220db 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -3349,7 +3349,9 @@ qemuDomainAttachVsockDevice(virQEMUDriver *driver,
     const char *fdprefix = "vsockfd";
     bool releaseaddr = false;
     g_autofree char *fdname = NULL;
-    g_autofree char *devstr = NULL;
+    g_autoptr(virJSONValue) devprops = NULL;
+    bool removeextension = false;
+    bool removehandle = false;
     int ret = -1;

     if (vm->def->vsock) {
@@ -3369,7 +3371,7 @@ qemuDomainAttachVsockDevice(virQEMUDriver *driver,

     fdname = g_strdup_printf("%s%u", fdprefix, vsockPriv->vhostfd);

-    if (!(devstr = qemuBuildVsockDevStr(vm->def, vsock, priv->qemuCaps, fdprefix)))
+    if (!(devprops = qemuBuildVsockDevProps(vm->def, vsock, priv->qemuCaps, fdprefix)))
         goto cleanup;

     qemuDomainObjEnterMonitor(driver, vm);
@@ -3377,10 +3379,15 @@ qemuDomainAttachVsockDevice(virQEMUDriver *driver,
     if (qemuDomainAttachExtensionDevice(priv->mon, &vsock->info) < 0)
         goto exit_monitor;

-    if (qemuMonitorAddDeviceWithFd(priv->mon, devstr, vsockPriv->vhostfd, fdname) < 0) {
-        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &vsock->info));
+    removeextension = true;
+
+    if ((ret = qemuMonitorSendFileHandle(priv->mon, fdname, vsockPriv->vhostfd)) < 0)
+        goto exit_monitor;
+
+    removehandle = true;
+
+    if ((ret = qemuMonitorAddDeviceProps(priv->mon, &devprops)) < 0)
         goto exit_monitor;
-    }

     if (qemuDomainObjExitMonitor(driver, vm) < 0) {
         releaseaddr = false;
@@ -3402,6 +3409,10 @@ qemuDomainAttachVsockDevice(virQEMUDriver *driver,
     return ret;

  exit_monitor:
+    if (removehandle)
+        ignore_value(qemuMonitorCloseFileHandle(priv->mon, fdname));
+    if (removeextension)
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &vsock->info));
     if (qemuDomainObjExitMonitor(driver, vm) < 0)
         releaseaddr = false;
     goto cleanup;
-- 
2.31.1