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[PATCH 1/4] hisi_acc_vfio_pci: fix VF reset timeout issue

Longfang Liu posted 4 patches 1 month ago
There is a newer version of this series
[PATCH 1/4] hisi_acc_vfio_pci: fix VF reset timeout issue
Posted by Longfang Liu 1 month ago 
From: Weili Qian <qianweili@huawei.com>

If device error occurs during live migration, qemu will
reset the VF. At this time, VF reset and device reset are performed
simultaneously. The VF reset will timeout. Therefore, the QM_RESETTING
flag is used to ensure that VF reset and device reset are performed
serially.

Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration")
Signed-off-by: Weili Qian <qianweili@huawei.com>
---
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 24 +++++++++++++++++++
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  2 ++
 2 files changed, 26 insertions(+)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index fe2ffcd00d6e..d55365b21f78 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -1188,14 +1188,37 @@ hisi_acc_vfio_pci_get_device_state(struct vfio_device *vdev,
 	return 0;
 }
 
+static void hisi_acc_vf_pci_reset_prepare(struct pci_dev *pdev)
+{
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
+	struct hisi_qm *qm = hisi_acc_vdev->pf_qm;
+	struct device *dev = &qm->pdev->dev;
+	u32 delay = 0;
+
+	/* All reset requests need to be queued for processing */
+	while (test_and_set_bit(QM_RESETTING, &qm->misc_ctl)) {
+		msleep(1);
+		if (++delay > QM_RESET_WAIT_TIMEOUT) {
+			dev_err(dev, "reset prepare failed\n");
+			return;
+		}
+	}
+
+	hisi_acc_vdev->set_reset_flag = true;
+}
+
 static void hisi_acc_vf_pci_aer_reset_done(struct pci_dev *pdev)
 {
 	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
+	struct hisi_qm *qm = hisi_acc_vdev->pf_qm;
 
 	if (hisi_acc_vdev->core_device.vdev.migration_flags !=
 				VFIO_MIGRATION_STOP_COPY)
 		return;
 
+	if (hisi_acc_vdev->set_reset_flag)
+		clear_bit(QM_RESETTING, &qm->misc_ctl);
+
 	mutex_lock(&hisi_acc_vdev->state_mutex);
 	hisi_acc_vf_reset(hisi_acc_vdev);
 	mutex_unlock(&hisi_acc_vdev->state_mutex);
@@ -1746,6 +1769,7 @@ static const struct pci_device_id hisi_acc_vfio_pci_table[] = {
 MODULE_DEVICE_TABLE(pci, hisi_acc_vfio_pci_table);
 
 static const struct pci_error_handlers hisi_acc_vf_err_handlers = {
+	.reset_prepare = hisi_acc_vf_pci_reset_prepare,
 	.reset_done = hisi_acc_vf_pci_aer_reset_done,
 	.error_detected = vfio_pci_core_aer_err_detected,
 };
diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
index cd55eba64dfb..a3d91a31e3d8 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
@@ -27,6 +27,7 @@
 
 #define ERROR_CHECK_TIMEOUT		100
 #define CHECK_DELAY_TIME		100
+#define QM_RESET_WAIT_TIMEOUT  60000
 
 #define QM_SQC_VFT_BASE_SHIFT_V2	28
 #define QM_SQC_VFT_BASE_MASK_V2		GENMASK(15, 0)
@@ -128,6 +129,7 @@ struct hisi_acc_vf_migration_file {
 struct hisi_acc_vf_core_device {
 	struct vfio_pci_core_device core_device;
 	u8 match_done;
+	bool set_reset_flag;
 	/*
 	 * io_base is only valid when dev_opened is true,
 	 * which is protected by open_mutex.
-- 
2.24.0
Re: [PATCH 1/4] hisi_acc_vfio_pci: fix VF reset timeout issue
Posted by Alex Williamson 3 weeks, 2 days ago 
On Sun, 4 Jan 2026 15:07:03 +0800
Longfang Liu <liulongfang@huawei.com> wrote:

> From: Weili Qian <qianweili@huawei.com>
> 
> If device error occurs during live migration, qemu will
> reset the VF. At this time, VF reset and device reset are performed
> simultaneously. The VF reset will timeout. Therefore, the QM_RESETTING
> flag is used to ensure that VF reset and device reset are performed
> serially.
> 
> Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration")
> Signed-off-by: Weili Qian <qianweili@huawei.com>
> ---
>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 24 +++++++++++++++++++
>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  2 ++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> index fe2ffcd00d6e..d55365b21f78 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> @@ -1188,14 +1188,37 @@ hisi_acc_vfio_pci_get_device_state(struct vfio_device *vdev,
>  	return 0;
>  }
>  
> +static void hisi_acc_vf_pci_reset_prepare(struct pci_dev *pdev)
> +{
> +	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
> +	struct hisi_qm *qm = hisi_acc_vdev->pf_qm;
> +	struct device *dev = &qm->pdev->dev;
> +	u32 delay = 0;
> +
> +	/* All reset requests need to be queued for processing */
> +	while (test_and_set_bit(QM_RESETTING, &qm->misc_ctl)) {
> +		msleep(1);
> +		if (++delay > QM_RESET_WAIT_TIMEOUT) {
> +			dev_err(dev, "reset prepare failed\n");
> +			return;
> +		}
> +	}
> +
> +	hisi_acc_vdev->set_reset_flag = true;
> +}
> +
>  static void hisi_acc_vf_pci_aer_reset_done(struct pci_dev *pdev)
>  {
>  	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
> +	struct hisi_qm *qm = hisi_acc_vdev->pf_qm;
>  
>  	if (hisi_acc_vdev->core_device.vdev.migration_flags !=
>  				VFIO_MIGRATION_STOP_COPY)
>  		return;
>  
> +	if (hisi_acc_vdev->set_reset_flag)
> +		clear_bit(QM_RESETTING, &qm->misc_ctl);


.reset_prepare sets QM_RESETTING unconditionally, .reset_done clears
QM_RESETTING conditionally based on the migration state.  In 2/ this
becomes conditional on the device supporting migration ops.  Doesn't
this enable a scenario where a device that does not support migration
puts QM_RESETTING into an inconsistent state that is never cleared?
Should the clear_bit() occur before the migration state/capability
check?

Thanks,
Alex

> +
>  	mutex_lock(&hisi_acc_vdev->state_mutex);
>  	hisi_acc_vf_reset(hisi_acc_vdev);
>  	mutex_unlock(&hisi_acc_vdev->state_mutex);
> @@ -1746,6 +1769,7 @@ static const struct pci_device_id hisi_acc_vfio_pci_table[] = {
>  MODULE_DEVICE_TABLE(pci, hisi_acc_vfio_pci_table);
>  
>  static const struct pci_error_handlers hisi_acc_vf_err_handlers = {
> +	.reset_prepare = hisi_acc_vf_pci_reset_prepare,
>  	.reset_done = hisi_acc_vf_pci_aer_reset_done,
>  	.error_detected = vfio_pci_core_aer_err_detected,
>  };
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> index cd55eba64dfb..a3d91a31e3d8 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> @@ -27,6 +27,7 @@
>  
>  #define ERROR_CHECK_TIMEOUT		100
>  #define CHECK_DELAY_TIME		100
> +#define QM_RESET_WAIT_TIMEOUT  60000
>  
>  #define QM_SQC_VFT_BASE_SHIFT_V2	28
>  #define QM_SQC_VFT_BASE_MASK_V2		GENMASK(15, 0)
> @@ -128,6 +129,7 @@ struct hisi_acc_vf_migration_file {
>  struct hisi_acc_vf_core_device {
>  	struct vfio_pci_core_device core_device;
>  	u8 match_done;
> +	bool set_reset_flag;
>  	/*
>  	 * io_base is only valid when dev_opened is true,
>  	 * which is protected by open_mutex.
Re: [PATCH 1/4] hisi_acc_vfio_pci: fix VF reset timeout issue
Posted by liulongfang 2 weeks, 6 days ago 
On 2026/1/17 0:47, Alex Williamson wrote:
> On Sun, 4 Jan 2026 15:07:03 +0800
> Longfang Liu <liulongfang@huawei.com> wrote:
> 
>> From: Weili Qian <qianweili@huawei.com>
>>
>> If device error occurs during live migration, qemu will
>> reset the VF. At this time, VF reset and device reset are performed
>> simultaneously. The VF reset will timeout. Therefore, the QM_RESETTING
>> flag is used to ensure that VF reset and device reset are performed
>> serially.
>>
>> Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration")
>> Signed-off-by: Weili Qian <qianweili@huawei.com>
>> ---
>>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 24 +++++++++++++++++++
>>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  2 ++
>>  2 files changed, 26 insertions(+)
>>
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> index fe2ffcd00d6e..d55365b21f78 100644
>> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> @@ -1188,14 +1188,37 @@ hisi_acc_vfio_pci_get_device_state(struct vfio_device *vdev,
>>  	return 0;
>>  }
>>  
>> +static void hisi_acc_vf_pci_reset_prepare(struct pci_dev *pdev)
>> +{
>> +	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
>> +	struct hisi_qm *qm = hisi_acc_vdev->pf_qm;
>> +	struct device *dev = &qm->pdev->dev;
>> +	u32 delay = 0;
>> +
>> +	/* All reset requests need to be queued for processing */
>> +	while (test_and_set_bit(QM_RESETTING, &qm->misc_ctl)) {
>> +		msleep(1);
>> +		if (++delay > QM_RESET_WAIT_TIMEOUT) {
>> +			dev_err(dev, "reset prepare failed\n");
>> +			return;
>> +		}
>> +	}
>> +
>> +	hisi_acc_vdev->set_reset_flag = true;
>> +}
>> +
>>  static void hisi_acc_vf_pci_aer_reset_done(struct pci_dev *pdev)
>>  {
>>  	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
>> +	struct hisi_qm *qm = hisi_acc_vdev->pf_qm;
>>  
>>  	if (hisi_acc_vdev->core_device.vdev.migration_flags !=
>>  				VFIO_MIGRATION_STOP_COPY)
>>  		return;
>>  
>> +	if (hisi_acc_vdev->set_reset_flag)
>> +		clear_bit(QM_RESETTING, &qm->misc_ctl);
> 
> 
> .reset_prepare sets QM_RESETTING unconditionally, .reset_done clears
> QM_RESETTING conditionally based on the migration state.  In 2/ this
> becomes conditional on the device supporting migration ops.  Doesn't
> this enable a scenario where a device that does not support migration
> puts QM_RESETTING into an inconsistent state that is never cleared?
> Should the clear_bit() occur before the migration state/capability
> check?
>

Yes,  it makes more sense to move clear_bit() before the migration state
or capability check.

Thanks,
Longfang.

> Thanks,
> Alex
> 
>> +
>>  	mutex_lock(&hisi_acc_vdev->state_mutex);
>>  	hisi_acc_vf_reset(hisi_acc_vdev);
>>  	mutex_unlock(&hisi_acc_vdev->state_mutex);
>> @@ -1746,6 +1769,7 @@ static const struct pci_device_id hisi_acc_vfio_pci_table[] = {
>>  MODULE_DEVICE_TABLE(pci, hisi_acc_vfio_pci_table);
>>  
>>  static const struct pci_error_handlers hisi_acc_vf_err_handlers = {
>> +	.reset_prepare = hisi_acc_vf_pci_reset_prepare,
>>  	.reset_done = hisi_acc_vf_pci_aer_reset_done,
>>  	.error_detected = vfio_pci_core_aer_err_detected,
>>  };
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
>> index cd55eba64dfb..a3d91a31e3d8 100644
>> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
>> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
>> @@ -27,6 +27,7 @@
>>  
>>  #define ERROR_CHECK_TIMEOUT		100
>>  #define CHECK_DELAY_TIME		100
>> +#define QM_RESET_WAIT_TIMEOUT  60000
>>  
>>  #define QM_SQC_VFT_BASE_SHIFT_V2	28
>>  #define QM_SQC_VFT_BASE_MASK_V2		GENMASK(15, 0)
>> @@ -128,6 +129,7 @@ struct hisi_acc_vf_migration_file {
>>  struct hisi_acc_vf_core_device {
>>  	struct vfio_pci_core_device core_device;
>>  	u8 match_done;
>> +	bool set_reset_flag;
>>  	/*
>>  	 * io_base is only valid when dev_opened is true,
>>  	 * which is protected by open_mutex.
> 
> .
>

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