On Tue, Oct 31, 2023 at 4:12 AM Abdullah Sevincer
<abdullah.sevin...@intel.com> wrote:
>
> vfio-pci driver in Linux kernel 6.2 enables PASID by default.
> In DLB hardware, enabling PASID puts DLB in SIOV mode. This
> breaks DLB PF-PMD mode. For DLB PF-PMD mode to function properly
> PASID needs to be disabled for kernel 6.2.
>
> In this commit this issue is addressed and PASID is disabled
> by writing a zero to PASID control register.
>
> Fixes: 5433956d5185 ("event/dlb2: add eventdev probe")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Abdullah Sevincer <abdullah.sevin...@intel.com>
> ---
> drivers/event/dlb2/pf/dlb2_main.c | 27 +++++++++++++++++++++++++++
> lib/pci/rte_pci.h | 5 +++++
> 2 files changed, 32 insertions(+)
>
> diff --git a/drivers/event/dlb2/pf/dlb2_main.c
> b/drivers/event/dlb2/pf/dlb2_main.c
> index aa03e4c311..34e47a4e33 100644
> --- a/drivers/event/dlb2/pf/dlb2_main.c
> +++ b/drivers/event/dlb2/pf/dlb2_main.c
> @@ -190,6 +190,7 @@ dlb2_pf_reset(struct dlb2_dev *dlb2_dev)
> uint16_t rt_ctl_word;
> uint32_t pri_reqs_dword;
> uint16_t pri_ctrl_word;
> + uint16_t pasid_ctrl;
>
> off_t pcie_cap_offset;
> int pri_cap_offset;
> @@ -197,6 +198,7 @@ dlb2_pf_reset(struct dlb2_dev *dlb2_dev)
> int err_cap_offset;
> int acs_cap_offset;
> int wait_count;
> + int pasid_cap_offset;
>
> uint16_t devsta_busy_word;
> uint16_t devctl_word;
> @@ -514,6 +516,31 @@ dlb2_pf_reset(struct dlb2_dev *dlb2_dev)
> }
> }
>
> + /* TODO - The current Linux kernel 6.2 vfio driver does not expose
> PASID capability to
> + * users. It also enables PASID by default, which breaks DLB PF PMD.
> We have
> + * to use the hardcoded offset for now to disable PASID. It may be
> different for
> + * other device drivers since they may have different design. When
> PASID capability
> + * is exposed to users, please revise this part and add api to
> disable PASID through
> + * pci common code.
> + */
> + pasid_cap_offset = RTE_PCI_PASID_CAP_OFFSET;
> +
> + off = pasid_cap_offset + RTE_PCI_PASID_CTRL;
> + if (rte_pci_read_config(pdev, &pasid_ctrl, 2, off) != 2)
> + pasid_ctrl = 0;
> +
> + if (pasid_ctrl) {
> + DLB2_INFO(dlb2_dev, "DLB2 disabling pasid...\n");
> +
> + pasid_ctrl = 0;
> + ret = rte_pci_write_config(pdev, &pasid_ctrl, 2, off);
> + if (ret != 2) {
> + DLB2_LOG_ERR("[%s()] failed to write the pcie config
> space at offset %d\n",
> + __func__, (int)off);
> + return ret;
> + }
> + }
> +
> return 0;
> }
This patch can be splited as two,
1) Generic PCIe function to enable/disable PASID
2) Call generic function to disable PASID in drivers/event/dlb2/. Also
mention which Linux kernel commit
is introducing this issue in the git commit log.
