[PATCH 6.19 493/781] hisi_acc_vfio_pci: fix VF reset timeout issue

Greg Kroah-Hartman
2026-02-25T01:36:07Z

From: Weili Qian <qianweili@huawei.com>

[ Upstream commit a22099ed7936f8e8dabbdbadd97d56047797116b ]

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>
Link: https://lore.kernel.org/r/20260122020205.2884497-2-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../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 cf45f6370c369..d1e8053640a98 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -1188,9 +1188,32 @@ 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->set_reset_flag)
+ clear_bit(QM_RESETTING, &qm->misc_ctl);

if (hisi_acc_vdev->core_device.vdev.migration_flags !=
VFIO_MIGRATION_STOP_COPY)
@@ -1734,6 +1757,7 @@ 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 cd55eba64dfb2..a3d91a31e3d88 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.
--
2.51.0