From 6a2ee1fd8d36ed8407b403a7307de1633462759c Mon Sep 17 00:00:00 2001

From: Peter Xu <peterx@redhat.com>

Date: Wed, 9 Oct 2019 12:39:45 +0100

Subject: [PATCH 19/22] qdev/machine: Introduce hotplug_allowed hook

RH-Author: Peter Xu <peterx@redhat.com>

Message-id: <20191009123947.21505-4-peterx@redhat.com>

Patchwork-id: 91351

O-Subject: [RHEL-8.2.0 qemu-kvm PATCH 3/5] qdev/machine: Introduce hotplug_allowed hook

Bugzilla: 1738440

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Auger Eric <eric.auger@redhat.com>

RH-Acked-by: Alex Williamson <alex.williamson@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

Conflicts:

  hw/core/qdev.c: don't have 14405c274e86e ("qdev: Provide

    qdev_get_bus_hotplug_handler()")

  include/hw/boards: plenty of new things missing in

    MachineClass (kvm_type, numa_mem_supported, smp_parse)

  include/hw/qdev-core.h: don't have 17cc0128da3 ("qdev: Let machine

    hotplug handler to override bus hotplug handler")

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 <eric.auger@redhat.com>

Signed-off-by: Peter Xu <peterx@redhat.com>

Message-Id: <20190916080718.3299-3-peterx@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

(cherry picked from commit d2321d31ff98b75b652c2b1594f00a4cfd48102a)

Signed-off-by: Peter Xu <peterx@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 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 24f1ae7..5971242 100644

--- a/hw/core/qdev.c

+++ b/hw/core/qdev.c

@@ -259,6 +259,23 @@ 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_hotplug_handler(DeviceState *dev)

 {

     HotplugHandler *hotplug_ctrl;

diff --git a/include/hw/boards.h b/include/hw/boards.h

index 9b4a69b..e568a3c 100644

--- a/include/hw/boards.h

+++ b/include/hw/boards.h

@@ -156,6 +156,13 @@ typedef struct {

  *    should instead use "unimplemented-device" for all memory ranges where

  *    the guest will attempt to probe for a device that QEMU doesn't

  *    implement and a stub device is required.

+ * @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 >*/

@@ -210,6 +217,8 @@ 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 9453588..b8d1cac 100644

--- a/include/hw/qdev-core.h

+++ b/include/hw/qdev-core.h

@@ -286,6 +286,7 @@ void qdev_init_nofail(DeviceState *dev);

 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,

                                  int required_for_version);

 HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev);

+bool qdev_hotplug_allowed(DeviceState *dev, Error **errp);

 HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev);

 void qdev_unplug(DeviceState *dev, Error **errp);

 void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev,

diff --git a/qdev-monitor.c b/qdev-monitor.c

index f439b83..70bce8f 100644

--- a/qdev-monitor.c

+++ b/qdev-monitor.c

@@ -606,6 +606,13 @@ 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)) {

-- 

1.8.3.1