[Linuxarm] Re: [PATCH v3 2/4] hisi_acc_vfio_pci: Create subfunction for data reading

-----Original Message----- From: liulongfang liulongfang@huawei.com Sent: Thursday, March 7, 2024 6:04 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 v3 2/4] hisi_acc_vfio_pci: Create subfunction for data reading

During the live migration process. It needs to obtain various status data of drivers and devices. In order to facilitate calling it in the debugfs function. For all operations that read data from device registers, the driver creates a subfunction. Also fixed the location of address data.

Signed-off-by: Longfang Liu liulongfang@huawei.com

.../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 55 ++++++++++--------- .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 3 + 2 files changed, 33 insertions(+), 25 deletions(-)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 45351be8e270..1881f3fa9266 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -486,42 +486,22 @@ static int vf_qm_load_data(struct hisi_acc_vf_core_device *hisi_acc_vdev, return 0; }

-static int vf_qm_state_save(struct hisi_acc_vf_core_device *hisi_acc_vdev,

• 	    struct hisi_acc_vf_migration_file *migf)
  

+static int vf_qm_read_data(struct hisi_qm *vf_qm, struct acc_vf_data *vf_data) {

• struct acc_vf_data *vf_data = &migf->vf_data;

• struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm; struct device *dev = &vf_qm->pdev->dev; int ret;

• if (unlikely(qm_wait_dev_not_ready(vf_qm))) {

• /* Update state and return with match data */
  

• vf_data->vf_qm_state = QM_NOT_READY;
  

• hisi_acc_vdev->vf_qm_state = vf_data->vf_qm_state;
  

• migf->total_length = QM_MATCH_SIZE;
  

• return 0;
  

• }

• vf_data->vf_qm_state = QM_READY;

• hisi_acc_vdev->vf_qm_state = vf_data->vf_qm_state;

• ret = vf_qm_cache_wb(vf_qm);

• if (ret) {

• dev_err(dev, "failed to writeback QM Cache!\n");
  

• return ret;
  

• }

• ret = qm_get_regs(vf_qm, vf_data);

So this doesn't need the qm_wait_dev_not_ready(vf_qm) check above for the debugfs ? What happens if you read when device is not ready?

if (ret) return -EINVAL;

/* Every reg is 32 bit, the dma address is 64 bit. */

• vf_data->eqe_dma = vf_data->qm_eqc_dw[1];

• vf_data->eqe_dma = vf_data->qm_eqc_dw[QM_XQC_ADDR_HIGH];

Also since there is no serialization with core migration now, what will be the data returned in debugfs when there is a vf_qm_load_data() is in progress?

So I guess the intention or assumption here is that the debugfs data is only valid when the user knows that devices not under migration process.

Is that right?

Thanks, Shameer

vf_data->eqe_dma <<= QM_XQC_ADDR_OFFSET;

• vf_data->eqe_dma |= vf_data->qm_eqc_dw[0];
• vf_data->aeqe_dma = vf_data->qm_aeqc_dw[1];

• vf_data->eqe_dma |= vf_data->qm_eqc_dw[QM_XQC_ADDR_LOW];
• vf_data->aeqe_dma = vf_data-

...

qm_aeqc_dw[QM_XQC_ADDR_HIGH];

vf_data->aeqe_dma <<= QM_XQC_ADDR_OFFSET;

• vf_data->aeqe_dma |= vf_data->qm_aeqc_dw[0];

• vf_data->aeqe_dma |= vf_data-

...

qm_aeqc_dw[QM_XQC_ADDR_LOW];

/* Through SQC_BT/CQC_BT to get sqc and cqc address */ ret = qm_get_sqc(vf_qm, &vf_data->sqc_dma); @@ -536,6 +516,31 @@ static int vf_qm_state_save(struct hisi_acc_vf_core_device *hisi_acc_vdev, return -EINVAL; }

• return 0;

+}

+static int vf_qm_state_save(struct hisi_acc_vf_core_device *hisi_acc_vdev,

• 	    struct hisi_acc_vf_migration_file *migf)
  

+{

• struct acc_vf_data *vf_data = &migf->vf_data;
• struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm;
• int ret;
• if (unlikely(qm_wait_dev_not_ready(vf_qm))) {

• /* Update state and return with match data */
  

• vf_data->vf_qm_state = QM_NOT_READY;
  

• hisi_acc_vdev->vf_qm_state = vf_data->vf_qm_state;
  

• migf->total_length = QM_MATCH_SIZE;
  

• return 0;
  

• }
• vf_data->vf_qm_state = QM_READY;
• hisi_acc_vdev->vf_qm_state = vf_data->vf_qm_state;
• ret = vf_qm_read_data(vf_qm, vf_data);
• if (ret)

• return -EINVAL;
  

• migf->total_length = sizeof(struct acc_vf_data); return 0;

} diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h index 5bab46602fad..7a9dc87627cd 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h @@ -38,6 +38,9 @@ #define QM_REG_ADDR_OFFSET 0x0004

#define QM_XQC_ADDR_OFFSET 32U +#define QM_XQC_ADDR_LOW 0x1 +#define QM_XQC_ADDR_HIGH 0x2

#define QM_VF_AEQ_INT_MASK 0x0004 #define QM_VF_EQ_INT_MASK 0x000c

#define QM_IFC_INT_SOURCE_V 0x0020

2.24.0