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[Qemu-devel] [PATCH v3 2/4] qdev/machine: Introduce hotplug_allowed hook
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH v3 2/4] qdev/machine: Introduce hotplug_allowed hook |
Date: |
Mon, 16 Sep 2019 16:07:16 +0800 |
Introduce this new per-machine hook to give any machine class a chance
to do a sanity check on the to-be-hotplugged device as a sanity test.
This will be used for x86 to try to detect some illegal configuration
of devices, e.g., possible conflictions between vfio-pci and x86
vIOMMU.
Reviewed-by: Eric Auger <address@hidden>
Signed-off-by: Peter Xu <address@hidden>
---
hw/core/qdev.c | 17 +++++++++++++++++
include/hw/boards.h | 9 +++++++++
include/hw/qdev-core.h | 1 +
qdev-monitor.c | 7 +++++++
4 files changed, 34 insertions(+)
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 60d66c2f39..cbad6c1d55 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -237,6 +237,23 @@ HotplugHandler
*qdev_get_machine_hotplug_handler(DeviceState *dev)
return NULL;
}
+bool qdev_hotplug_allowed(DeviceState *dev, Error **errp)
+{
+ MachineState *machine;
+ MachineClass *mc;
+ Object *m_obj = qdev_get_machine();
+
+ if (object_dynamic_cast(m_obj, TYPE_MACHINE)) {
+ machine = MACHINE(m_obj);
+ mc = MACHINE_GET_CLASS(machine);
+ if (mc->hotplug_allowed) {
+ return mc->hotplug_allowed(machine, dev, errp);
+ }
+ }
+
+ return true;
+}
+
HotplugHandler *qdev_get_bus_hotplug_handler(DeviceState *dev)
{
if (dev->parent_bus) {
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 2289536e48..be18a5c032 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -166,6 +166,13 @@ typedef struct {
* The function pointer to hook different machine specific functions for
* parsing "smp-opts" from QemuOpts to MachineState::CpuTopology and more
* machine specific topology fields, such as smp_dies for PCMachine.
+ * @hotplug_allowed:
+ * If the hook is provided, then it'll be called for each device
+ * hotplug to check whether the device hotplug is allowed. Return
+ * true to grant allowance or false to reject the hotplug. When
+ * false is returned, an error must be set to show the reason of
+ * the rejection. If the hook is not provided, all hotplug will be
+ * allowed.
*/
struct MachineClass {
/*< private >*/
@@ -224,6 +231,8 @@ struct MachineClass {
HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
DeviceState *dev);
+ bool (*hotplug_allowed)(MachineState *state, DeviceState *dev,
+ Error **errp);
CpuInstanceProperties (*cpu_index_to_instance_props)(MachineState *machine,
unsigned cpu_index);
const CPUArchIdList *(*possible_cpu_arch_ids)(MachineState *machine);
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index de70b7a19a..aa123f88cb 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -280,6 +280,7 @@ void qdev_set_legacy_instance_id(DeviceState *dev, int
alias_id,
int required_for_version);
HotplugHandler *qdev_get_bus_hotplug_handler(DeviceState *dev);
HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev);
+bool qdev_hotplug_allowed(DeviceState *dev, Error **errp);
/**
* qdev_get_hotplug_handler: Get handler responsible for device wiring
*
diff --git a/qdev-monitor.c b/qdev-monitor.c
index 8fe5c2cad2..148df9cacf 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -615,6 +615,13 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
/* create device */
dev = DEVICE(object_new(driver));
+ /* Check whether the hotplug is allowed by the machine */
+ if (qdev_hotplug && !qdev_hotplug_allowed(dev, &err)) {
+ /* Error must be set in the machine hook */
+ assert(err);
+ goto err_del_dev;
+ }
+
if (bus) {
qdev_set_parent_bus(dev, bus);
} else if (qdev_hotplug && !qdev_get_machine_hotplug_handler(dev)) {
--
2.21.0