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Message-ID: <c508502a-6f60-120a-c9f9-53911549bc77@amd.com>
Date: Tue, 11 Apr 2023 10:09:42 -0700
From: Brett Creeley <bcreeley@....com>
To: Alex Williamson <alex.williamson@...hat.com>,
Brett Creeley <brett.creeley@....com>
Cc: kvm@...r.kernel.org, netdev@...r.kernel.org, jgg@...dia.com,
yishaih@...dia.com, shameerali.kolothum.thodi@...wei.com,
kevin.tian@...el.com, shannon.nelson@....com, drivers@...sando.io,
simon.horman@...igine.com
Subject: Re: [PATCH v8 vfio 3/7] vfio/pds: register with the pds_core PF
On 4/10/2023 1:41 PM, Alex Williamson wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
>
>
> On Tue, 4 Apr 2023 12:01:37 -0700
> Brett Creeley <brett.creeley@....com> wrote:
>
>> The pds_core driver will supply adminq services, so find the PF
>> and register with the DSC services.
>>
>> Use the following commands to enable a VF:
>> echo 1 > /sys/bus/pci/drivers/pds_core/$PF_BDF/sriov_numvfs
>>
>> Signed-off-by: Brett Creeley <brett.creeley@....com>
>> Signed-off-by: Shannon Nelson <shannon.nelson@....com>
>> ---
>> drivers/vfio/pci/pds/Makefile | 1 +
>> drivers/vfio/pci/pds/cmds.c | 69 +++++++++++++++++++++++++++++++++
>> drivers/vfio/pci/pds/cmds.h | 10 +++++
>> drivers/vfio/pci/pds/pci_drv.c | 16 +++++++-
>> drivers/vfio/pci/pds/pci_drv.h | 9 +++++
>> drivers/vfio/pci/pds/vfio_dev.c | 5 +++
>> drivers/vfio/pci/pds/vfio_dev.h | 2 +
>> include/linux/pds/pds_lm.h | 12 ++++++
>> 8 files changed, 123 insertions(+), 1 deletion(-)
>> create mode 100644 drivers/vfio/pci/pds/cmds.c
>> create mode 100644 drivers/vfio/pci/pds/cmds.h
>> create mode 100644 drivers/vfio/pci/pds/pci_drv.h
>> create mode 100644 include/linux/pds/pds_lm.h
>>
>> diff --git a/drivers/vfio/pci/pds/Makefile b/drivers/vfio/pci/pds/Makefile
>> index e1a55ae0f079..87581111fa17 100644
>> --- a/drivers/vfio/pci/pds/Makefile
>> +++ b/drivers/vfio/pci/pds/Makefile
>> @@ -4,5 +4,6 @@
>> obj-$(CONFIG_PDS_VFIO_PCI) += pds_vfio.o
>>
>> pds_vfio-y := \
>> + cmds.o \
>> pci_drv.o \
>> vfio_dev.o
>> diff --git a/drivers/vfio/pci/pds/cmds.c b/drivers/vfio/pci/pds/cmds.c
>> new file mode 100644
>> index 000000000000..7807dbb2c72c
>> --- /dev/null
>> +++ b/drivers/vfio/pci/pds/cmds.c
>> @@ -0,0 +1,69 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
>> +
>> +#include <linux/io.h>
>> +#include <linux/types.h>
>> +
>> +#include <linux/pds/pds_common.h>
>> +#include <linux/pds/pds_core_if.h>
>> +#include <linux/pds/pds_adminq.h>
>> +#include <linux/pds/pds_lm.h>
>> +
>> +#include "vfio_dev.h"
>> +#include "cmds.h"
>> +
>> +int
>> +pds_vfio_register_client_cmd(struct pds_vfio_pci_device *pds_vfio)
>> +{
>> + union pds_core_adminq_comp comp = { 0 };
>> + union pds_core_adminq_cmd cmd = { 0 };
>> + struct device *dev;
>> + int err;
>> + u32 id;
>> + u16 ci;
>> +
>> + id = PCI_DEVID(pds_vfio->pdev->bus->number,
>> + pci_iov_virtfn_devfn(pds_vfio->pdev, pds_vfio->vf_id));
>
> Does this actually work?
>
> pds_vfio_pci_probe() is presumably called with a VF pdev because it
> calls pdsc_get_pf_struct() -> pci_iov_get_pf_drvdata(), which returns
> an error if !dev->is_virtfn. pds_vfio_init_device() also stores the
> vf_id from pci_iov_vf_id(), which requires that it's called on a VF,
> not PF. This same pdev gets stored at pds_vfio->pdev.
>
> OTOH, pci_iov_virtfn_devfn() used here errors if !dev->is_physfn. So I
> expect we're calling PCI_DEVID with the second arg as -EINVAL. The
> first arg would also be suspicious if pds_vfio->pdev were the PF since
> then we'd be making a PCI_DEVID combining the PF bus number and the VF
> devfn.
>
> We've also already stored the VF PCI_DEVID at pds_vfio->pci_id, so
> creating it again seems entirely unnecessary.
>
> Also, since we never check the return of pdsc_get_pf_struct() I'd guess
> we take a segfault referencing off of pds_vfio->pdsc should the driver
> bind to something other than expected. Validating the PF drvdata
> before anything else seems like a good first stop in
> pds_vfio_pci_probe().
>
> It's also a little curious why we're storing the pdev at all in the
> pds_vfio_pci_device when it's readily available from the embedded
> vfio_pci_core_device. Thanks,
>
> Alex
>
Yeah, these are all good catches and I'm not sure how I didn't notice
them before. I will rework these bits based on your feedback.
Thanks,
Brett
>> +
>> + dev = &pds_vfio->pdev->dev;
>> + cmd.client_reg.opcode = PDS_AQ_CMD_CLIENT_REG;
>> + snprintf(cmd.client_reg.devname, sizeof(cmd.client_reg.devname),
>> + "%s.%d-%u", PDS_LM_DEV_NAME,
>> + pci_domain_nr(pds_vfio->pdev->bus), id);
>> +
>> + err = pdsc_adminq_post(pds_vfio->pdsc, &cmd, &comp, false);
>> + if (err) {
>> + dev_info(dev, "register with DSC failed, status %d: %pe\n",
>> + comp.status, ERR_PTR(err));
>> + return err;
>> + }
>> +
>> + ci = le16_to_cpu(comp.client_reg.client_id);
>> + if (!ci) {
>> + dev_err(dev, "%s: device returned null client_id\n", __func__);
>> + return -EIO;
>> + }
>> + pds_vfio->client_id = ci;
>> +
>> + return 0;
>> +}
>> +
>> +void
>> +pds_vfio_unregister_client_cmd(struct pds_vfio_pci_device *pds_vfio)
>> +{
>> + union pds_core_adminq_comp comp = { 0 };
>> + union pds_core_adminq_cmd cmd = { 0 };
>> + struct device *dev;
>> + int err;
>> +
>> + dev = &pds_vfio->pdev->dev;
>> + cmd.client_unreg.opcode = PDS_AQ_CMD_CLIENT_UNREG;
>> + cmd.client_unreg.client_id = cpu_to_le16(pds_vfio->client_id);
>> +
>> + err = pdsc_adminq_post(pds_vfio->pdsc, &cmd, &comp, false);
>> + if (err)
>> + dev_info(dev, "unregister from DSC failed, status %d: %pe\n",
>> + comp.status, ERR_PTR(err));
>> +
>> + pds_vfio->client_id = 0;
>> +}
>> diff --git a/drivers/vfio/pci/pds/cmds.h b/drivers/vfio/pci/pds/cmds.h
>> new file mode 100644
>> index 000000000000..4c592afccf89
>> --- /dev/null
>> +++ b/drivers/vfio/pci/pds/cmds.h
>> @@ -0,0 +1,10 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
>> +
>> +#ifndef _CMDS_H_
>> +#define _CMDS_H_
>> +
>> +int pds_vfio_register_client_cmd(struct pds_vfio_pci_device *pds_vfio);
>> +void pds_vfio_unregister_client_cmd(struct pds_vfio_pci_device *pds_vfio);
>> +
>> +#endif /* _CMDS_H_ */
>> diff --git a/drivers/vfio/pci/pds/pci_drv.c b/drivers/vfio/pci/pds/pci_drv.c
>> index 5e554420792e..46537afdee2d 100644
>> --- a/drivers/vfio/pci/pds/pci_drv.c
>> +++ b/drivers/vfio/pci/pds/pci_drv.c
>> @@ -8,9 +8,13 @@
>> #include <linux/types.h>
>> #include <linux/vfio.h>
>>
>> +#include <linux/pds/pds_common.h>
>> #include <linux/pds/pds_core_if.h>
>> +#include <linux/pds/pds_adminq.h>
>>
>> #include "vfio_dev.h"
>> +#include "pci_drv.h"
>> +#include "cmds.h"
>>
>> #define PDS_VFIO_DRV_NAME "pds_vfio"
>> #define PDS_VFIO_DRV_DESCRIPTION "AMD/Pensando VFIO Device Driver"
>> @@ -30,13 +34,23 @@ pds_vfio_pci_probe(struct pci_dev *pdev,
>>
>> dev_set_drvdata(&pdev->dev, &pds_vfio->vfio_coredev);
>> pds_vfio->pdev = pdev;
>> + pds_vfio->pdsc = pdsc_get_pf_struct(pdev);
>> +
>> + err = pds_vfio_register_client_cmd(pds_vfio);
>> + if (err) {
>> + dev_err(&pdev->dev, "failed to register as client: %pe\n",
>> + ERR_PTR(err));
>> + goto out_put_vdev;
>> + }
>>
>> err = vfio_pci_core_register_device(&pds_vfio->vfio_coredev);
>> if (err)
>> - goto out_put_vdev;
>> + goto out_unreg_client;
>>
>> return 0;
>>
>> +out_unreg_client:
>> + pds_vfio_unregister_client_cmd(pds_vfio);
>> out_put_vdev:
>> vfio_put_device(&pds_vfio->vfio_coredev.vdev);
>> return err;
>> diff --git a/drivers/vfio/pci/pds/pci_drv.h b/drivers/vfio/pci/pds/pci_drv.h
>> new file mode 100644
>> index 000000000000..e79bed12ed14
>> --- /dev/null
>> +++ b/drivers/vfio/pci/pds/pci_drv.h
>> @@ -0,0 +1,9 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Copyright(c) 2023 Advanced Micro Devices, Inc. */
>> +
>> +#ifndef _PCI_DRV_H
>> +#define _PCI_DRV_H
>> +
>> +#include <linux/pci.h>
>> +
>> +#endif /* _PCI_DRV_H */
>> diff --git a/drivers/vfio/pci/pds/vfio_dev.c b/drivers/vfio/pci/pds/vfio_dev.c
>> index 0f70efec01e1..056715dea512 100644
>> --- a/drivers/vfio/pci/pds/vfio_dev.c
>> +++ b/drivers/vfio/pci/pds/vfio_dev.c
>> @@ -31,6 +31,11 @@ pds_vfio_init_device(struct vfio_device *vdev)
>> pds_vfio->vf_id = pci_iov_vf_id(pdev);
>> pds_vfio->pci_id = PCI_DEVID(pdev->bus->number, pdev->devfn);
>>
>> + dev_dbg(&pdev->dev, "%s: PF %#04x VF %#04x (%d) vf_id %d domain %d pds_vfio %p\n",
>> + __func__, pci_dev_id(pdev->physfn),
>> + pds_vfio->pci_id, pds_vfio->pci_id, pds_vfio->vf_id,
>> + pci_domain_nr(pdev->bus), pds_vfio);
>> +
>> return 0;
>> }
>>
>> diff --git a/drivers/vfio/pci/pds/vfio_dev.h b/drivers/vfio/pci/pds/vfio_dev.h
>> index a66f8069b88c..10557e8dc829 100644
>> --- a/drivers/vfio/pci/pds/vfio_dev.h
>> +++ b/drivers/vfio/pci/pds/vfio_dev.h
>> @@ -10,9 +10,11 @@
>> struct pds_vfio_pci_device {
>> struct vfio_pci_core_device vfio_coredev;
>> struct pci_dev *pdev;
>> + void *pdsc;
>>
>> int vf_id;
>> int pci_id;
>> + u16 client_id;
>> };
>>
>> const struct vfio_device_ops *pds_vfio_ops_info(void);
>> diff --git a/include/linux/pds/pds_lm.h b/include/linux/pds/pds_lm.h
>> new file mode 100644
>> index 000000000000..2bc2bf79426e
>> --- /dev/null
>> +++ b/include/linux/pds/pds_lm.h
>> @@ -0,0 +1,12 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Copyright(c) 2022 Pensando Systems, Inc */
>> +
>> +#ifndef _PDS_LM_H_
>> +#define _PDS_LM_H_
>> +
>> +#include "pds_common.h"
>> +
>> +#define PDS_DEV_TYPE_LM_STR "LM"
>> +#define PDS_LM_DEV_NAME PDS_CORE_DRV_NAME "." PDS_DEV_TYPE_LM_STR
>> +
>> +#endif /* _PDS_LM_H_ */
>
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