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// 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_IMPORT_NS(IOMMUFD);
MODULE_DESCRIPTION(PDS_VFIO_DRV_DESCRIPTION);
MODULE_AUTHOR("Brett Creeley <brett.creeley@amd.com>");
MODULE_LICENSE("GPL");
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