On Tue, 18 Mar 2025 14:45:48 +0800
Longfang Liu <liulongfang@xxxxxxxxxx> wrote:
> 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@xxxxxxxxxx>
> Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
> ---
> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 21 ++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> index cadc82419dca..68b1c7204cad 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> @@ -426,13 +426,6 @@ static int vf_qm_check_match(struct hisi_acc_vf_core_device *hisi_acc_vdev,
> return -EINVAL;
> }
>
> - ret = qm_write_regs(vf_qm, QM_VF_STATE, &vf_data->vf_qm_state, 1);
> - if (ret) {
> - dev_err(dev, "failed to write QM_VF_STATE\n");
> - return ret;
> - }
> -
> - hisi_acc_vdev->vf_qm_state = vf_data->vf_qm_state;
> hisi_acc_vdev->match_done = true;
> return 0;
> }
> @@ -498,6 +491,13 @@ static int vf_qm_load_data(struct hisi_acc_vf_core_device *hisi_acc_vdev,
> if (migf->total_length < sizeof(struct acc_vf_data))
> return -EINVAL;
>
> + ret = qm_write_regs(qm, QM_VF_STATE, &vf_data->vf_qm_state, 1);
> + if (ret) {
> + dev_err(dev, "failed to write QM_VF_STATE\n");
> + return -EINVAL;
> + }
> + hisi_acc_vdev->vf_qm_state = vf_data->vf_qm_state;
> +
> qm->eqe_dma = vf_data->eqe_dma;
> qm->aeqe_dma = vf_data->aeqe_dma;
> qm->sqc_dma = vf_data->sqc_dma;
> @@ -506,6 +506,12 @@ 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;
> + }
> +
I'm not sure how this fits in based on the commit log. IIUC, we're
actually rejecting the migration data here, which will cause a
migration failure. We're also testing the validity of the data *after*
we've actually applied it to the hisi_qm object, which seems backwards.
Are we just not processing the migration data because there's no driver
or are we failing the migration? There shouldn't be a requirement on
the state of the guest driver for a successful migration. Thanks,
Alex
> ret = qm_set_regs(qm, vf_data);
> if (ret) {
> dev_err(dev, "set VF regs failed\n");
> @@ -1531,6 +1537,7 @@ 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);
>
