When a PF is bound to the driver via driver_override and passed through to a VM, its pf_qm stays NULL. The PCI error handler reset_prepare() runs during open_device through pci_try_reset_function(), before the mig_ops gate, and dereferences the NULL pf_qm for the timeout log, crashing the kernel. Move the mig_ops check to the entry of reset_prepare() and aer_reset_done() so non-migration devices skip the QM_RESETTING coordination. The dev local resolved &qm->pdev->dev before the gate, so open code it at the dev_err() call where qm is known valid. Also clear set_reset_flag together with QM_RESETTING in aer_reset_done(); the flag was never cleared before, so a later timed-out reset could release a foreign lock. Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Fixes: a22099ed7936f ("hisi_acc_vfio_pci: fix VF reset timeout issue") Signed-off-by: Longfang Liu --- drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 86362ec424a5..e6fdf4d2e581 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -1154,14 +1154,16 @@ 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; + if (!hisi_acc_vdev->core_device.vdev.mig_ops) + return; + /* 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"); + dev_err(&qm->pdev->dev, "reset prepare failed\n"); return; } } @@ -1174,12 +1176,14 @@ 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.mig_ops) return; + if (hisi_acc_vdev->set_reset_flag) { + clear_bit(QM_RESETTING, &qm->misc_ctl); + hisi_acc_vdev->set_reset_flag = false; + } + mutex_lock(&hisi_acc_vdev->state_mutex); hisi_acc_vf_reset(hisi_acc_vdev); mutex_unlock(&hisi_acc_vdev->state_mutex); -- 2.43.0