Re: [RFC PATCH v4 08/10] i40e/vf_migration: VF live migration - pass-through VF first

Xiang Zheng
2020-06-11T02:28:00Z

On 2020/6/11 8:23, Yan Zhao wrote:
> On Wed, Jun 10, 2020 at 04:59:43PM +0800, Xiang Zheng wrote:
>> Hi Yan,
>>
>> few nits below...
>>
>> On 2020/5/18 10:53, Yan Zhao wrote:
>>> This driver intercepts all device operations as long as it's probed
>>> successfully by vfio-pci driver.
>>>
>>> It will process regions and irqs of its interest and then forward
>>> operations to default handlers exported from vfio pci if it wishes to.
>>>
>>> In this patch, this driver does nothing but pass through VFs to guest
>>> by calling to exported handlers from driver vfio-pci.
>>>
>>> Cc: Shaopeng He <shaopeng.he@intel.com>
>>>
>>> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
>>> ---
>>> drivers/net/ethernet/intel/Kconfig | 10 ++
>>> drivers/net/ethernet/intel/i40e/Makefile | 2 +
>>> .../ethernet/intel/i40e/i40e_vf_migration.c | 165 ++++++++++++++++++
>>> .../ethernet/intel/i40e/i40e_vf_migration.h | 59 +++++++
>>> 4 files changed, 236 insertions(+)
>>> create mode 100644 drivers/net/ethernet/intel/i40e/i40e_vf_migration.c
>>> create mode 100644 drivers/net/ethernet/intel/i40e/i40e_vf_migration.h
>>>
>>> diff --git a/drivers/net/ethernet/intel/Kconfig b/drivers/net/ethernet/intel/Kconfig
>>> index ad34e4335df2..31780d9a59f1 100644
>>> --- a/drivers/net/ethernet/intel/Kconfig
>>> +++ b/drivers/net/ethernet/intel/Kconfig
>>> @@ -264,6 +264,16 @@ config I40E_DCB
>>>
>>> If unsure, say N.
>>>

[...]

>>> diff --git a/drivers/net/ethernet/intel/i40e/i40e_vf_migration.h b/drivers/net/ethernet/intel/i40e/i40e_vf_migration.h
>>> new file mode 100644
>>> index 000000000000..696d40601ec3
>>> --- /dev/null
>>> +++ b/drivers/net/ethernet/intel/i40e/i40e_vf_migration.h
>>> @@ -0,0 +1,59 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>> +/* Copyright(c) 2013 - 2019 Intel Corporation. */
>>> +
>>> +#ifndef I40E_MIG_H
>>> +#define I40E_MIG_H
>>> +
>>> +#include <linux/pci.h>
>>> +#include <linux/vfio.h>
>>> +#include <linux/mdev.h>
>>> +
>>> +#include "i40e.h"
>>> +#include "i40e_txrx.h"
>>> +
>>> +/* helper macros copied from vfio-pci */
>>> +#define VFIO_PCI_OFFSET_SHIFT 40
>>> +#define VFIO_PCI_OFFSET_TO_INDEX(off) ((off) >> VFIO_PCI_OFFSET_SHIFT)
>>> +#define VFIO_PCI_INDEX_TO_OFFSET(index) ((u64)(index) << VFIO_PCI_OFFSET_SHIFT)
>>> +#define VFIO_PCI_OFFSET_MASK (((u64)(1) << VFIO_PCI_OFFSET_SHIFT) - 1)
>>> +
>>> +/* Single Root I/O Virtualization */
>>> +struct pci_sriov {
>>> + int pos; /* Capability position */
>>> + int nres; /* Number of resources */
>>> + u32 cap; /* SR-IOV Capabilities */
>>> + u16 ctrl; /* SR-IOV Control */
>>> + u16 total_VFs; /* Total VFs associated with the PF */
>>> + u16 initial_VFs; /* Initial VFs associated with the PF */
>>> + u16 num_VFs; /* Number of VFs available */
>>> + u16 offset; /* First VF Routing ID offset */
>>> + u16 stride; /* Following VF stride */
>>> + u16 vf_device; /* VF device ID */
>>> + u32 pgsz; /* Page size for BAR alignment */
>>> + u8 link; /* Function Dependency Link */
>>> + u8 max_VF_buses; /* Max buses consumed by VFs */
>>> + u16 driver_max_VFs; /* Max num VFs driver supports */
>>> + struct pci_dev *dev; /* Lowest numbered PF */
>>> + struct pci_dev *self; /* This PF */
>>> + u32 cfg_size; /* VF config space size */
>>> + u32 class; /* VF device */
>>> + u8 hdr_type; /* VF header type */
>>> + u16 subsystem_vendor; /* VF subsystem vendor */
>>> + u16 subsystem_device; /* VF subsystem device */
>>> + resource_size_t barsz[PCI_SRIOV_NUM_BARS]; /* VF BAR size */
>>> + bool drivers_autoprobe; /* Auto probing of VFs by driver */
>>> +};
>>> +
>>
>> Can "struct pci_sriov" be extracted for common use? This should not be exclusive
>> for "i40e_vf migration support".
>>
> the definition of this structure is actually in driver/pci/pci.h.
> maybe removing the copy here and use below include is better?
> #include "../../../../pci/pci.h"
>

How about moving the definition from driver/pci/pci.h into include/linux/pci.h? So
we can just include "linux/pci.h" and removing the copy here.

--
Thanks,
Xiang