RE: [PATCH v5 1/5] hisi_acc_vfio_pci: fix XQE dma address error

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: liulongfang <liulongfang@xxxxxxxxxx>
> Sent: Thursday, March 13, 2025 7:20 AM
> To: alex.williamson@xxxxxxxxxx; jgg@xxxxxxxxxx; Shameerali Kolothum
> Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>; Jonathan Cameron
> <jonathan.cameron@xxxxxxxxxx>
> Cc: kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> linuxarm@xxxxxxxxxxxxx; liulongfang <liulongfang@xxxxxxxxxx>
> Subject: [PATCH v5 1/5] hisi_acc_vfio_pci: fix XQE dma address error
> 
> The dma addresses of EQE and AEQE are wrong after migration and
> results in guest kernel-mode encryption services  failure.
> Comparing the definition of hardware registers, we found that
> there was an error when the data read from the register was
> combined into an address. Therefore, the address combination
> sequence needs to be corrected.
> 
> Even after fixing the above problem, we still have an issue
> where the Guest from an old kernel can get migrated to
> new kernel and may result in wrong data.
> 
> In order to ensure that the address is correct after migration,
> if an old magic number is detected, the dma address needs to be
> updated.
> 
> Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live
> migration")
> Signed-off-by: Longfang Liu <liulongfang@xxxxxxxxxx>

LGTM,

Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>

Thanks,
Shameer

> ---
>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 41 ++++++++++++++++---
>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    | 14 ++++++-
>  2 files changed, 47 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> index 451c639299eb..304dbdfa0e95 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> @@ -350,6 +350,32 @@ static int vf_qm_func_stop(struct hisi_qm *qm)
>  	return hisi_qm_mb(qm, QM_MB_CMD_PAUSE_QM, 0, 0, 0);
>  }
> 
> +static int vf_qm_version_check(struct acc_vf_data *vf_data, struct device
> *dev)
> +{
> +	switch (vf_data->acc_magic) {
> +	case ACC_DEV_MAGIC_V2:
> +		if (vf_data->major_ver != ACC_DRV_MAJOR_VER) {
> +			dev_info(dev, "migration driver version<%u.%u> not
> match!\n",
> +				 vf_data->major_ver, vf_data->minor_ver);
> +			return -EINVAL;
> +		}
> +		break;
> +	case ACC_DEV_MAGIC_V1:
> +		/* Correct dma address */
> +		vf_data->eqe_dma = vf_data-
> >qm_eqc_dw[QM_XQC_ADDR_HIGH];
> +		vf_data->eqe_dma <<= QM_XQC_ADDR_OFFSET;
> +		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[QM_XQC_ADDR_LOW];
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  static int vf_qm_check_match(struct hisi_acc_vf_core_device
> *hisi_acc_vdev,
>  			     struct hisi_acc_vf_migration_file *migf)
>  {
> @@ -363,7 +389,8 @@ static int vf_qm_check_match(struct
> hisi_acc_vf_core_device *hisi_acc_vdev,
>  	if (migf->total_length < QM_MATCH_SIZE || hisi_acc_vdev-
> >match_done)
>  		return 0;
> 
> -	if (vf_data->acc_magic != ACC_DEV_MAGIC) {
> +	ret = vf_qm_version_check(vf_data, dev);
> +	if (ret) {
>  		dev_err(dev, "failed to match ACC_DEV_MAGIC\n");
>  		return -EINVAL;
>  	}
> @@ -418,7 +445,9 @@ static int vf_qm_get_match_data(struct
> hisi_acc_vf_core_device *hisi_acc_vdev,
>  	int vf_id = hisi_acc_vdev->vf_id;
>  	int ret;
> 
> -	vf_data->acc_magic = ACC_DEV_MAGIC;
> +	vf_data->acc_magic = ACC_DEV_MAGIC_V2;
> +	vf_data->major_ver = ACC_DRV_MAJOR_VER;
> +	vf_data->minor_ver = ACC_DRV_MINOR_VER;
>  	/* Save device id */
>  	vf_data->dev_id = hisi_acc_vdev->vf_dev->device;
> 
> @@ -496,12 +525,12 @@ static int vf_qm_read_data(struct hisi_qm
> *vf_qm, struct acc_vf_data *vf_data)
>  		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];
>  	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);
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> index 245d7537b2bc..91002ceeebc1 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> @@ -39,6 +39,9 @@
>  #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
> @@ -50,10 +53,15 @@
>  #define QM_EQC_DW0		0X8000
>  #define QM_AEQC_DW0		0X8020
> 
> +#define ACC_DRV_MAJOR_VER 1
> +#define ACC_DRV_MINOR_VER 0
> +
> +#define ACC_DEV_MAGIC_V1	0XCDCDCDCDFEEDAACC
> +#define ACC_DEV_MAGIC_V2	0xAACCFEEDDECADEDE
> +
>  struct acc_vf_data {
>  #define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
>  	/* QM match information */
> -#define ACC_DEV_MAGIC	0XCDCDCDCDFEEDAACC
>  	u64 acc_magic;
>  	u32 qp_num;
>  	u32 dev_id;
> @@ -61,7 +69,9 @@ struct acc_vf_data {
>  	u32 qp_base;
>  	u32 vf_qm_state;
>  	/* QM reserved match information */
> -	u32 qm_rsv_state[3];
> +	u16 major_ver;
> +	u16 minor_ver;
> +	u32 qm_rsv_state[2];
> 
>  	/* QM RW regs */
>  	u32 aeq_int_mask;
> --
> 2.24.0