diff options
Diffstat (limited to 'drivers/vfio/pci/pds/pci_drv.c')
| -rw-r--r-- | drivers/vfio/pci/pds/pci_drv.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/vfio/pci/pds/pci_drv.c b/drivers/vfio/pci/pds/pci_drv.c new file mode 100644 index 000000000000..ab4b5958e413 --- /dev/null +++ b/drivers/vfio/pci/pds/pci_drv.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2023 Advanced Micro Devices, Inc. */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/pci.h> +#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_DESCRIPTION "AMD/Pensando VFIO Device Driver" +#define PCI_VENDOR_ID_PENSANDO 0x1dd8 + +static void pds_vfio_recovery(struct pds_vfio_pci_device *pds_vfio) +{ + bool deferred_reset_needed = false; + + /* + * Documentation states that the kernel migration driver must not + * generate asynchronous device state transitions outside of + * manipulation by the user or the VFIO_DEVICE_RESET ioctl. + * + * Since recovery is an asynchronous event received from the device, + * initiate a deferred reset. Issue a deferred reset in the following + * situations: + * 1. Migration is in progress, which will cause the next step of + * the migration to fail. + * 2. If the device is in a state that will be set to + * VFIO_DEVICE_STATE_RUNNING on the next action (i.e. VM is + * shutdown and device is in VFIO_DEVICE_STATE_STOP). + */ + mutex_lock(&pds_vfio->state_mutex); + if ((pds_vfio->state != VFIO_DEVICE_STATE_RUNNING && + pds_vfio->state != VFIO_DEVICE_STATE_ERROR) || + (pds_vfio->state == VFIO_DEVICE_STATE_RUNNING && + pds_vfio_dirty_is_enabled(pds_vfio))) + deferred_reset_needed = true; + mutex_unlock(&pds_vfio->state_mutex); + + /* + * On the next user initiated state transition, the device will + * transition to the VFIO_DEVICE_STATE_ERROR. At this point it's the user's + * responsibility to reset the device. + * + * If a VFIO_DEVICE_RESET is requested post recovery and before the next + * state transition, then the deferred reset state will be set to + * VFIO_DEVICE_STATE_RUNNING. + */ + if (deferred_reset_needed) { + spin_lock(&pds_vfio->reset_lock); + pds_vfio->deferred_reset = true; + pds_vfio->deferred_reset_state = VFIO_DEVICE_STATE_ERROR; + spin_unlock(&pds_vfio->reset_lock); + } +} + +static int pds_vfio_pci_notify_handler(struct notifier_block *nb, + unsigned long ecode, void *data) +{ + struct pds_vfio_pci_device *pds_vfio = + container_of(nb, struct pds_vfio_pci_device, nb); + struct device *dev = pds_vfio_to_dev(pds_vfio); + union pds_core_notifyq_comp *event = data; + + dev_dbg(dev, "%s: event code %lu\n", __func__, ecode); + + /* + * We don't need to do anything for RESET state==0 as there is no notify + * or feedback mechanism available, and it is possible that we won't + * even see a state==0 event since the pds_core recovery is pending. + * + * Any requests from VFIO while state==0 will fail, which will return + * error and may cause migration to fail. + */ + if (ecode == PDS_EVENT_RESET) { + dev_info(dev, "%s: PDS_EVENT_RESET event received, state==%d\n", + __func__, event->reset.state); + /* + * pds_core device finished recovery and sent us the + * notification (state == 1) to allow us to recover + */ + if (event->reset.state == 1) + pds_vfio_recovery(pds_vfio); + } + + return 0; +} + +static int +pds_vfio_pci_register_event_handler(struct pds_vfio_pci_device *pds_vfio) +{ + struct device *dev = pds_vfio_to_dev(pds_vfio); + struct notifier_block *nb = &pds_vfio->nb; + int err; + + if (!nb->notifier_call) { + nb->notifier_call = pds_vfio_pci_notify_handler; + err = pdsc_register_notify(nb); + if (err) { + nb->notifier_call = NULL; + dev_err(dev, + "failed to register pds event handler: %pe\n", + ERR_PTR(err)); + return -EINVAL; + } + dev_dbg(dev, "pds event handler registered\n"); + } + + return 0; +} + +static void +pds_vfio_pci_unregister_event_handler(struct pds_vfio_pci_device *pds_vfio) +{ + if (pds_vfio->nb.notifier_call) { + pdsc_unregister_notify(&pds_vfio->nb); + pds_vfio->nb.notifier_call = NULL; + } +} + +static int pds_vfio_pci_probe(struct pci_dev *pdev, + const struct pci_device_id *id) +{ + struct pds_vfio_pci_device *pds_vfio; + int err; + + pds_vfio = vfio_alloc_device(pds_vfio_pci_device, vfio_coredev.vdev, + &pdev->dev, pds_vfio_ops_info()); + if (IS_ERR(pds_vfio)) + return PTR_ERR(pds_vfio); + + dev_set_drvdata(&pdev->dev, &pds_vfio->vfio_coredev); + + err = vfio_pci_core_register_device(&pds_vfio->vfio_coredev); + if (err) + goto out_put_vdev; + + 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_unregister_coredev; + } + + err = pds_vfio_pci_register_event_handler(pds_vfio); + if (err) + goto out_unregister_client; + + return 0; + +out_unregister_client: + pds_vfio_unregister_client_cmd(pds_vfio); +out_unregister_coredev: + vfio_pci_core_unregister_device(&pds_vfio->vfio_coredev); +out_put_vdev: + vfio_put_device(&pds_vfio->vfio_coredev.vdev); + return err; +} + +static void pds_vfio_pci_remove(struct pci_dev *pdev) +{ + struct pds_vfio_pci_device *pds_vfio = pds_vfio_pci_drvdata(pdev); + + pds_vfio_pci_unregister_event_handler(pds_vfio); + pds_vfio_unregister_client_cmd(pds_vfio); + vfio_pci_core_unregister_device(&pds_vfio->vfio_coredev); + vfio_put_device(&pds_vfio->vfio_coredev.vdev); +} + +static const struct pci_device_id pds_vfio_pci_table[] = { + { PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_PENSANDO, 0x1003) }, /* Ethernet VF */ + { 0, } +}; +MODULE_DEVICE_TABLE(pci, pds_vfio_pci_table); + +static void pds_vfio_pci_aer_reset_done(struct pci_dev *pdev) +{ + struct pds_vfio_pci_device *pds_vfio = pds_vfio_pci_drvdata(pdev); + + pds_vfio_reset(pds_vfio); +} + +static const struct pci_error_handlers pds_vfio_pci_err_handlers = { + .reset_done = pds_vfio_pci_aer_reset_done, + .error_detected = vfio_pci_core_aer_err_detected, +}; + +static struct pci_driver pds_vfio_pci_driver = { + .name = KBUILD_MODNAME, + .id_table = pds_vfio_pci_table, + .probe = pds_vfio_pci_probe, + .remove = pds_vfio_pci_remove, + .err_handler = &pds_vfio_pci_err_handlers, + .driver_managed_dma = true, +}; + +module_pci_driver(pds_vfio_pci_driver); + +MODULE_DESCRIPTION(PDS_VFIO_DRV_DESCRIPTION); +MODULE_AUTHOR("Brett Creeley <brett.creeley@amd.com>"); +MODULE_LICENSE("GPL"); |