-----Original Message----- From: liulongfang <liulongfang@huawei.com> Sent: Tuesday, February 25, 2025 6:28 AM To: alex.williamson@redhat.com; jgg@nvidia.com; Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>; Jonathan Cameron <jonathan.cameron@huawei.com> Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org; linuxarm@openeuler.org; liulongfang <liulongfang@huawei.com> Subject: [PATCH v4 5/5] hisi_acc_vfio_pci: bugfix live migration function without VF device driver

If the driver of the VF device is not loaded in the Guest OS, then perform device data migration. The migrated data address will be NULL.

May be rephrase: If the VF device driver is not loaded in the Guest OS and we attempt to perform device data migration, the address of the migrated data will be NULL.

The live migration recovery operation on the destination side will access a null address value, which will cause access errors.

Therefore, live migration of VMs without added VF device drivers does not require device data migration. In addition, when the queue address data obtained by the destination is empty, device queue recovery processing will not be performed.

Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Signed-off-by: Longfang Liu <liulongfang@huawei.com> --- drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 3f0bcd855839..77872fc4cd34 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -440,6 +440,7 @@ static int vf_qm_get_match_data(struct hisi_acc_vf_core_device *hisi_acc_vdev, struct acc_vf_data *vf_data) { struct hisi_qm *pf_qm = hisi_acc_vdev->pf_qm; + struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm; struct device *dev = &pf_qm->pdev->dev; int vf_id = hisi_acc_vdev->vf_id; int ret; @@ -466,6 +467,13 @@ static int vf_qm_get_match_data(struct hisi_acc_vf_core_device *hisi_acc_vdev, return ret; }

+ /* Get VF driver insmod state */ + ret = qm_read_regs(vf_qm, QM_VF_STATE, &vf_data->vf_qm_state, 1);

We already have qm_wait_dev_not_ready() function that checks the QM_VF_STATE. Why can't we use that here? Also we are getting this vf_qm_state already in vf_qm_state_save(). And you don't seem to check the vf_qm_state in vf_qm_check_match(). So why it is read early in this function? Thanks, Shameer

+ if (ret) { + dev_err(dev, "failed to read QM_VF_STATE!\n"); + return ret; + } + return 0; }

@@ -505,6 +513,12 @@ static int vf_qm_load_data(struct hisi_acc_vf_core_device *hisi_acc_vdev, qm->qp_base = vf_data->qp_base; qm->qp_num = vf_data->qp_num;

+ if (!vf_data->eqe_dma || !vf_data->aeqe_dma || + !vf_data->sqc_dma || !vf_data->cqc_dma) { + dev_err(dev, "resume dma addr is NULL!\n"); + return -EINVAL; + } + ret = qm_set_regs(qm, vf_data); if (ret) { dev_err(dev, "set VF regs failed\n"); @@ -727,6 +741,9 @@ static int hisi_acc_vf_load_state(struct hisi_acc_vf_core_device *hisi_acc_vdev) struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev-

...

resuming_migf; int ret;

+ if (hisi_acc_vdev->vf_qm_state != QM_READY) + return 0; + /* Recover data to VF */ ret = vf_qm_load_data(hisi_acc_vdev, migf); if (ret) { @@ -1530,6 +1547,7 @@ static int hisi_acc_vfio_pci_migrn_init_dev(struct vfio_device *core_vdev) hisi_acc_vdev->vf_id = pci_iov_vf_id(pdev) + 1; hisi_acc_vdev->pf_qm = pf_qm; hisi_acc_vdev->vf_dev = pdev; + hisi_acc_vdev->vf_qm_state = QM_NOT_READY; mutex_init(&hisi_acc_vdev->state_mutex); mutex_init(&hisi_acc_vdev->open_mutex);

-- 2.24.0