[v4,1/2] PCI: hv: Decouple the func definition in hv_dr_state from VSP message
diff mbox series

Message ID 1578946101-74036-1-git-send-email-longli@linuxonhyperv.com
State New
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  • [v4,1/2] PCI: hv: Decouple the func definition in hv_dr_state from VSP message
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Commit Message

Long Li Jan. 13, 2020, 8:08 p.m. UTC
From: Long Li <longli@microsoft.com>

hv_dr_state is used to find present PCI devices on the bus. The structure
reuses struct pci_function_description from VSP message to describe a
device.

To prepare support for pci_function_description v2, decouple this
dependence in hv_dr_state so it can work with both v1 and v2 VSP messages.

There is no functionality change.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
---
Changes
v2: Changed some spaces to tabs, changed failure code to -ENOMEM
v3: Revised comment for function hv_pci_devices_present(), reformatted patch title
v4: Fixed spelling

 drivers/pci/controller/pci-hyperv.c | 101 +++++++++++++++++++---------
 1 file changed, 70 insertions(+), 31 deletions(-)

Comments

Long Li Jan. 22, 2020, 9:42 p.m. UTC | #1
Hi Lorenzo,

Can you take a look at this patch?

Thanks

Long

>Subject: [Patch v4 1/2] PCI: hv: Decouple the func definition in hv_dr_state from
>VSP message
>
>From: Long Li <longli@microsoft.com>
>
>hv_dr_state is used to find present PCI devices on the bus. The structure reuses
>struct pci_function_description from VSP message to describe a device.
>
>To prepare support for pci_function_description v2, decouple this dependence in
>hv_dr_state so it can work with both v1 and v2 VSP messages.
>
>There is no functionality change.
>
>Signed-off-by: Long Li <longli@microsoft.com>
>Reviewed-by: Michael Kelley <mikelley@microsoft.com>
>---
>Changes
>v2: Changed some spaces to tabs, changed failure code to -ENOMEM
>v3: Revised comment for function hv_pci_devices_present(), reformatted patch
>title
>v4: Fixed spelling
>
> drivers/pci/controller/pci-hyperv.c | 101 +++++++++++++++++++---------
> 1 file changed, 70 insertions(+), 31 deletions(-)
>
>diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-
>hyperv.c
>index f1f300218fab..3b3e1967cf08 100644
>--- a/drivers/pci/controller/pci-hyperv.c
>+++ b/drivers/pci/controller/pci-hyperv.c
>@@ -507,10 +507,24 @@ struct hv_dr_work {
> 	struct hv_pcibus_device *bus;
> };
>
>+struct hv_pcidev_description {
>+	u16	v_id;	/* vendor ID */
>+	u16	d_id;	/* device ID */
>+	u8	rev;
>+	u8	prog_intf;
>+	u8	subclass;
>+	u8	base_class;
>+	u32	subsystem_id;
>+	union	win_slot_encoding win_slot;
>+	u32	ser;	/* serial number */
>+	u32	flags;
>+	u16	virtual_numa_node;
>+};
>+
> struct hv_dr_state {
> 	struct list_head list_entry;
> 	u32 device_count;
>-	struct pci_function_description func[0];
>+	struct hv_pcidev_description func[0];
> };
>
> enum hv_pcichild_state {
>@@ -527,7 +541,7 @@ struct hv_pci_dev {
> 	refcount_t refs;
> 	enum hv_pcichild_state state;
> 	struct pci_slot *pci_slot;
>-	struct pci_function_description desc;
>+	struct hv_pcidev_description desc;
> 	bool reported_missing;
> 	struct hv_pcibus_device *hbus;
> 	struct work_struct wrk;
>@@ -1862,7 +1876,7 @@ static void q_resource_requirements(void *context,
>struct pci_response *resp,
>  * Return: Pointer to the new tracking struct
>  */
> static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
>-		struct pci_function_description *desc)
>+		struct hv_pcidev_description *desc)
> {
> 	struct hv_pci_dev *hpdev;
> 	struct pci_child_message *res_req;
>@@ -1973,7 +1987,7 @@ static void pci_devices_present_work(struct
>work_struct *work)  {
> 	u32 child_no;
> 	bool found;
>-	struct pci_function_description *new_desc;
>+	struct hv_pcidev_description *new_desc;
> 	struct hv_pci_dev *hpdev;
> 	struct hv_pcibus_device *hbus;
> 	struct list_head removed;
>@@ -2090,43 +2104,26 @@ static void pci_devices_present_work(struct
>work_struct *work)
> 	put_hvpcibus(hbus);
> 	kfree(dr);
> }
>-
> /**
>- * hv_pci_devices_present() - Handles list of new children
>+ * hv_pci_start_relations_work() - Queue work to start device discovery
>  * @hbus:	Root PCI bus, as understood by this driver
>- * @relations:	Packet from host listing children
>+ * @dr:		The list of children returned from host
>  *
>- * This function is invoked whenever a new list of devices for
>- * this bus appears.
>+ * Return:  0 on success, -errno on failure
>  */
>-static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
>-				   struct pci_bus_relations *relations)
>+static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
>+				       struct hv_dr_state *dr)
> {
>-	struct hv_dr_state *dr;
> 	struct hv_dr_work *dr_wrk;
>-	unsigned long flags;
> 	bool pending_dr;
>+	unsigned long flags;
>
> 	dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
> 	if (!dr_wrk)
>-		return;
>-
>-	dr = kzalloc(offsetof(struct hv_dr_state, func) +
>-		     (sizeof(struct pci_function_description) *
>-		      (relations->device_count)), GFP_NOWAIT);
>-	if (!dr)  {
>-		kfree(dr_wrk);
>-		return;
>-	}
>+		return -ENOMEM;
>
> 	INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
> 	dr_wrk->bus = hbus;
>-	dr->device_count = relations->device_count;
>-	if (dr->device_count != 0) {
>-		memcpy(dr->func, relations->func,
>-		       sizeof(struct pci_function_description) *
>-		       dr->device_count);
>-	}
>
> 	spin_lock_irqsave(&hbus->device_list_lock, flags);
> 	/*
>@@ -2144,6 +2141,47 @@ static void hv_pci_devices_present(struct
>hv_pcibus_device *hbus,
> 		get_hvpcibus(hbus);
> 		queue_work(hbus->wq, &dr_wrk->wrk);
> 	}
>+
>+	return 0;
>+}
>+
>+/**
>+ * hv_pci_devices_present() - Handle list of new children
>+ * @hbus:	Root PCI bus, as understood by this driver
>+ * @relations:	Packet from host listing children
>+ *
>+ * Process a new list of devices on the bus. The list of devices is
>+ * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
>+ * whenever a new list of devices for this bus appears.
>+ */
>+static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
>+				   struct pci_bus_relations *relations) {
>+	struct hv_dr_state *dr;
>+	int i;
>+
>+	dr = kzalloc(offsetof(struct hv_dr_state, func) +
>+		     (sizeof(struct hv_pcidev_description) *
>+		      (relations->device_count)), GFP_NOWAIT);
>+
>+	if (!dr)
>+		return;
>+
>+	dr->device_count = relations->device_count;
>+	for (i = 0; i < dr->device_count; i++) {
>+		dr->func[i].v_id = relations->func[i].v_id;
>+		dr->func[i].d_id = relations->func[i].d_id;
>+		dr->func[i].rev = relations->func[i].rev;
>+		dr->func[i].prog_intf = relations->func[i].prog_intf;
>+		dr->func[i].subclass = relations->func[i].subclass;
>+		dr->func[i].base_class = relations->func[i].base_class;
>+		dr->func[i].subsystem_id = relations->func[i].subsystem_id;
>+		dr->func[i].win_slot = relations->func[i].win_slot;
>+		dr->func[i].ser = relations->func[i].ser;
>+	}
>+
>+	if (hv_pci_start_relations_work(hbus, dr))
>+		kfree(dr);
> }
>
> /**
>@@ -3018,7 +3056,7 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
> 		struct pci_packet teardown_packet;
> 		u8 buffer[sizeof(struct pci_message)];
> 	} pkt;
>-	struct pci_bus_relations relations;
>+	struct hv_dr_state *dr;
> 	struct hv_pci_compl comp_pkt;
> 	int ret;
>
>@@ -3030,8 +3068,9 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
> 		return;
>
> 	/* Delete any children which might still exist. */
>-	memset(&relations, 0, sizeof(relations));
>-	hv_pci_devices_present(hbus, &relations);
>+	dr = kzalloc(sizeof(*dr), GFP_KERNEL);
>+	if (dr && hv_pci_start_relations_work(hbus, dr))
>+		kfree(dr);
>
> 	ret = hv_send_resources_released(hdev);
> 	if (ret)
>--
>2.17.1
Long Li Feb. 6, 2020, 11:48 p.m. UTC | #2
Hi guys,

Ping again...

Please take a look at these two patches.

Thanks

Long

>Subject: RE: [Patch v4 1/2] PCI: hv: Decouple the func definition in hv_dr_state
>from VSP message
>
>Hi Lorenzo,
>
>Can you take a look at this patch?
>
>Thanks
>
>Long
>
>>Subject: [Patch v4 1/2] PCI: hv: Decouple the func definition in
>>hv_dr_state from VSP message
>>
>>From: Long Li <longli@microsoft.com>
>>
>>hv_dr_state is used to find present PCI devices on the bus. The
>>structure reuses struct pci_function_description from VSP message to describe
>a device.
>>
>>To prepare support for pci_function_description v2, decouple this
>>dependence in hv_dr_state so it can work with both v1 and v2 VSP messages.
>>
>>There is no functionality change.
>>
>>Signed-off-by: Long Li <longli@microsoft.com>
>>Reviewed-by: Michael Kelley <mikelley@microsoft.com>
>>---
>>Changes
>>v2: Changed some spaces to tabs, changed failure code to -ENOMEM
>>v3: Revised comment for function hv_pci_devices_present(), reformatted
>>patch title
>>v4: Fixed spelling
>>
>> drivers/pci/controller/pci-hyperv.c | 101 +++++++++++++++++++---------
>> 1 file changed, 70 insertions(+), 31 deletions(-)
>>
>>diff --git a/drivers/pci/controller/pci-hyperv.c
>>b/drivers/pci/controller/pci- hyperv.c index f1f300218fab..3b3e1967cf08
>>100644
>>--- a/drivers/pci/controller/pci-hyperv.c
>>+++ b/drivers/pci/controller/pci-hyperv.c
>>@@ -507,10 +507,24 @@ struct hv_dr_work {
>> 	struct hv_pcibus_device *bus;
>> };
>>
>>+struct hv_pcidev_description {
>>+	u16	v_id;	/* vendor ID */
>>+	u16	d_id;	/* device ID */
>>+	u8	rev;
>>+	u8	prog_intf;
>>+	u8	subclass;
>>+	u8	base_class;
>>+	u32	subsystem_id;
>>+	union	win_slot_encoding win_slot;
>>+	u32	ser;	/* serial number */
>>+	u32	flags;
>>+	u16	virtual_numa_node;
>>+};
>>+
>> struct hv_dr_state {
>> 	struct list_head list_entry;
>> 	u32 device_count;
>>-	struct pci_function_description func[0];
>>+	struct hv_pcidev_description func[0];
>> };
>>
>> enum hv_pcichild_state {
>>@@ -527,7 +541,7 @@ struct hv_pci_dev {
>> 	refcount_t refs;
>> 	enum hv_pcichild_state state;
>> 	struct pci_slot *pci_slot;
>>-	struct pci_function_description desc;
>>+	struct hv_pcidev_description desc;
>> 	bool reported_missing;
>> 	struct hv_pcibus_device *hbus;
>> 	struct work_struct wrk;
>>@@ -1862,7 +1876,7 @@ static void q_resource_requirements(void
>>*context, struct pci_response *resp,
>>  * Return: Pointer to the new tracking struct
>>  */
>> static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
>>-		struct pci_function_description *desc)
>>+		struct hv_pcidev_description *desc)
>> {
>> 	struct hv_pci_dev *hpdev;
>> 	struct pci_child_message *res_req;
>>@@ -1973,7 +1987,7 @@ static void pci_devices_present_work(struct
>>work_struct *work)  {
>> 	u32 child_no;
>> 	bool found;
>>-	struct pci_function_description *new_desc;
>>+	struct hv_pcidev_description *new_desc;
>> 	struct hv_pci_dev *hpdev;
>> 	struct hv_pcibus_device *hbus;
>> 	struct list_head removed;
>>@@ -2090,43 +2104,26 @@ static void pci_devices_present_work(struct
>>work_struct *work)
>> 	put_hvpcibus(hbus);
>> 	kfree(dr);
>> }
>>-
>> /**
>>- * hv_pci_devices_present() - Handles list of new children
>>+ * hv_pci_start_relations_work() - Queue work to start device
>>+ discovery
>>  * @hbus:	Root PCI bus, as understood by this driver
>>- * @relations:	Packet from host listing children
>>+ * @dr:		The list of children returned from host
>>  *
>>- * This function is invoked whenever a new list of devices for
>>- * this bus appears.
>>+ * Return:  0 on success, -errno on failure
>>  */
>>-static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
>>-				   struct pci_bus_relations *relations)
>>+static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
>>+				       struct hv_dr_state *dr)
>> {
>>-	struct hv_dr_state *dr;
>> 	struct hv_dr_work *dr_wrk;
>>-	unsigned long flags;
>> 	bool pending_dr;
>>+	unsigned long flags;
>>
>> 	dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
>> 	if (!dr_wrk)
>>-		return;
>>-
>>-	dr = kzalloc(offsetof(struct hv_dr_state, func) +
>>-		     (sizeof(struct pci_function_description) *
>>-		      (relations->device_count)), GFP_NOWAIT);
>>-	if (!dr)  {
>>-		kfree(dr_wrk);
>>-		return;
>>-	}
>>+		return -ENOMEM;
>>
>> 	INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
>> 	dr_wrk->bus = hbus;
>>-	dr->device_count = relations->device_count;
>>-	if (dr->device_count != 0) {
>>-		memcpy(dr->func, relations->func,
>>-		       sizeof(struct pci_function_description) *
>>-		       dr->device_count);
>>-	}
>>
>> 	spin_lock_irqsave(&hbus->device_list_lock, flags);
>> 	/*
>>@@ -2144,6 +2141,47 @@ static void hv_pci_devices_present(struct
>>hv_pcibus_device *hbus,
>> 		get_hvpcibus(hbus);
>> 		queue_work(hbus->wq, &dr_wrk->wrk);
>> 	}
>>+
>>+	return 0;
>>+}
>>+
>>+/**
>>+ * hv_pci_devices_present() - Handle list of new children
>>+ * @hbus:	Root PCI bus, as understood by this driver
>>+ * @relations:	Packet from host listing children
>>+ *
>>+ * Process a new list of devices on the bus. The list of devices is
>>+ * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
>>+ * whenever a new list of devices for this bus appears.
>>+ */
>>+static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
>>+				   struct pci_bus_relations *relations) {
>>+	struct hv_dr_state *dr;
>>+	int i;
>>+
>>+	dr = kzalloc(offsetof(struct hv_dr_state, func) +
>>+		     (sizeof(struct hv_pcidev_description) *
>>+		      (relations->device_count)), GFP_NOWAIT);
>>+
>>+	if (!dr)
>>+		return;
>>+
>>+	dr->device_count = relations->device_count;
>>+	for (i = 0; i < dr->device_count; i++) {
>>+		dr->func[i].v_id = relations->func[i].v_id;
>>+		dr->func[i].d_id = relations->func[i].d_id;
>>+		dr->func[i].rev = relations->func[i].rev;
>>+		dr->func[i].prog_intf = relations->func[i].prog_intf;
>>+		dr->func[i].subclass = relations->func[i].subclass;
>>+		dr->func[i].base_class = relations->func[i].base_class;
>>+		dr->func[i].subsystem_id = relations->func[i].subsystem_id;
>>+		dr->func[i].win_slot = relations->func[i].win_slot;
>>+		dr->func[i].ser = relations->func[i].ser;
>>+	}
>>+
>>+	if (hv_pci_start_relations_work(hbus, dr))
>>+		kfree(dr);
>> }
>>
>> /**
>>@@ -3018,7 +3056,7 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
>> 		struct pci_packet teardown_packet;
>> 		u8 buffer[sizeof(struct pci_message)];
>> 	} pkt;
>>-	struct pci_bus_relations relations;
>>+	struct hv_dr_state *dr;
>> 	struct hv_pci_compl comp_pkt;
>> 	int ret;
>>
>>@@ -3030,8 +3068,9 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
>> 		return;
>>
>> 	/* Delete any children which might still exist. */
>>-	memset(&relations, 0, sizeof(relations));
>>-	hv_pci_devices_present(hbus, &relations);
>>+	dr = kzalloc(sizeof(*dr), GFP_KERNEL);
>>+	if (dr && hv_pci_start_relations_work(hbus, dr))
>>+		kfree(dr);
>>
>> 	ret = hv_send_resources_released(hdev);
>> 	if (ret)
>>--
>>2.17.1

Patch
diff mbox series

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index f1f300218fab..3b3e1967cf08 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -507,10 +507,24 @@  struct hv_dr_work {
 	struct hv_pcibus_device *bus;
 };
 
+struct hv_pcidev_description {
+	u16	v_id;	/* vendor ID */
+	u16	d_id;	/* device ID */
+	u8	rev;
+	u8	prog_intf;
+	u8	subclass;
+	u8	base_class;
+	u32	subsystem_id;
+	union	win_slot_encoding win_slot;
+	u32	ser;	/* serial number */
+	u32	flags;
+	u16	virtual_numa_node;
+};
+
 struct hv_dr_state {
 	struct list_head list_entry;
 	u32 device_count;
-	struct pci_function_description func[0];
+	struct hv_pcidev_description func[0];
 };
 
 enum hv_pcichild_state {
@@ -527,7 +541,7 @@  struct hv_pci_dev {
 	refcount_t refs;
 	enum hv_pcichild_state state;
 	struct pci_slot *pci_slot;
-	struct pci_function_description desc;
+	struct hv_pcidev_description desc;
 	bool reported_missing;
 	struct hv_pcibus_device *hbus;
 	struct work_struct wrk;
@@ -1862,7 +1876,7 @@  static void q_resource_requirements(void *context, struct pci_response *resp,
  * Return: Pointer to the new tracking struct
  */
 static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
-		struct pci_function_description *desc)
+		struct hv_pcidev_description *desc)
 {
 	struct hv_pci_dev *hpdev;
 	struct pci_child_message *res_req;
@@ -1973,7 +1987,7 @@  static void pci_devices_present_work(struct work_struct *work)
 {
 	u32 child_no;
 	bool found;
-	struct pci_function_description *new_desc;
+	struct hv_pcidev_description *new_desc;
 	struct hv_pci_dev *hpdev;
 	struct hv_pcibus_device *hbus;
 	struct list_head removed;
@@ -2090,43 +2104,26 @@  static void pci_devices_present_work(struct work_struct *work)
 	put_hvpcibus(hbus);
 	kfree(dr);
 }
-
 /**
- * hv_pci_devices_present() - Handles list of new children
+ * hv_pci_start_relations_work() - Queue work to start device discovery
  * @hbus:	Root PCI bus, as understood by this driver
- * @relations:	Packet from host listing children
+ * @dr:		The list of children returned from host
  *
- * This function is invoked whenever a new list of devices for
- * this bus appears.
+ * Return:  0 on success, -errno on failure
  */
-static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
-				   struct pci_bus_relations *relations)
+static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
+				       struct hv_dr_state *dr)
 {
-	struct hv_dr_state *dr;
 	struct hv_dr_work *dr_wrk;
-	unsigned long flags;
 	bool pending_dr;
+	unsigned long flags;
 
 	dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
 	if (!dr_wrk)
-		return;
-
-	dr = kzalloc(offsetof(struct hv_dr_state, func) +
-		     (sizeof(struct pci_function_description) *
-		      (relations->device_count)), GFP_NOWAIT);
-	if (!dr)  {
-		kfree(dr_wrk);
-		return;
-	}
+		return -ENOMEM;
 
 	INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
 	dr_wrk->bus = hbus;
-	dr->device_count = relations->device_count;
-	if (dr->device_count != 0) {
-		memcpy(dr->func, relations->func,
-		       sizeof(struct pci_function_description) *
-		       dr->device_count);
-	}
 
 	spin_lock_irqsave(&hbus->device_list_lock, flags);
 	/*
@@ -2144,6 +2141,47 @@  static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
 		get_hvpcibus(hbus);
 		queue_work(hbus->wq, &dr_wrk->wrk);
 	}
+
+	return 0;
+}
+
+/**
+ * hv_pci_devices_present() - Handle list of new children
+ * @hbus:	Root PCI bus, as understood by this driver
+ * @relations:	Packet from host listing children
+ *
+ * Process a new list of devices on the bus. The list of devices is
+ * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
+ * whenever a new list of devices for this bus appears.
+ */
+static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
+				   struct pci_bus_relations *relations)
+{
+	struct hv_dr_state *dr;
+	int i;
+
+	dr = kzalloc(offsetof(struct hv_dr_state, func) +
+		     (sizeof(struct hv_pcidev_description) *
+		      (relations->device_count)), GFP_NOWAIT);
+
+	if (!dr)
+		return;
+
+	dr->device_count = relations->device_count;
+	for (i = 0; i < dr->device_count; i++) {
+		dr->func[i].v_id = relations->func[i].v_id;
+		dr->func[i].d_id = relations->func[i].d_id;
+		dr->func[i].rev = relations->func[i].rev;
+		dr->func[i].prog_intf = relations->func[i].prog_intf;
+		dr->func[i].subclass = relations->func[i].subclass;
+		dr->func[i].base_class = relations->func[i].base_class;
+		dr->func[i].subsystem_id = relations->func[i].subsystem_id;
+		dr->func[i].win_slot = relations->func[i].win_slot;
+		dr->func[i].ser = relations->func[i].ser;
+	}
+
+	if (hv_pci_start_relations_work(hbus, dr))
+		kfree(dr);
 }
 
 /**
@@ -3018,7 +3056,7 @@  static void hv_pci_bus_exit(struct hv_device *hdev)
 		struct pci_packet teardown_packet;
 		u8 buffer[sizeof(struct pci_message)];
 	} pkt;
-	struct pci_bus_relations relations;
+	struct hv_dr_state *dr;
 	struct hv_pci_compl comp_pkt;
 	int ret;
 
@@ -3030,8 +3068,9 @@  static void hv_pci_bus_exit(struct hv_device *hdev)
 		return;
 
 	/* Delete any children which might still exist. */
-	memset(&relations, 0, sizeof(relations));
-	hv_pci_devices_present(hbus, &relations);
+	dr = kzalloc(sizeof(*dr), GFP_KERNEL);
+	if (dr && hv_pci_start_relations_work(hbus, dr))
+		kfree(dr);
 
 	ret = hv_send_resources_released(hdev);
 	if (ret)