Re: [PATCH 093/103] qemuBuildVsockCommandLine: Generate via JSON

[Ján Tomko]

On a Thursday in 2021, Peter Krempa wrote:

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= -  (default: 0)
 vhostfd=

Signed-off-by: Peter Krempa 
---
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(-)



Reviewed-by: Ján Tomko 

Jano


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[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= -  (default: 0)
  vhostfd=

Signed-off-by: Peter Krempa 
---
 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(, qemuCaps, VIR_DOMAIN_DEVICE_VSOCK, vsock) 
< 0) {
+if (!(props = qemuBuildVirtioDevProps(VIR_DOMAIN_DEVICE_VSOCK, vsock, 
qemuCaps)))
 return NULL;
-}

-virBufferAsprintf(, ",id=%s", vsock->info.alias);
-virBufferAsprintf(, ",guest-cid=%u", vsock->guest_cid);
-virBufferAsprintf(, ",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(, def, >info) < 0)
+if (qemuBuildDeviceAddressProps(props, def, >info) < 0)
 return NULL;

-return virBufferContentAndReset();
+return g_steal_pointer();
 }


@@ -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, >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);
@@