alistair23-linux/drivers/vfio/vfio_spapr_eeh.c
Sam Bobroff 1ef52073fd powerpc/eeh: Improve recovery of passed-through devices
Currently, the EEH recovery process considers passed-through devices
as if they were not EEH-aware, which can cause them to be removed as
part of recovery.  Because device removal requires cooperation from
the guest, this may lead to the process stalling or deadlocking.
Also, if devices are removed on the host side, they will be removed
from their IOMMU group, making recovery in the guest impossible.

Therefore, alter the recovery process so that passed-through devices
are not removed but are instead left frozen (and marked isolated)
until the guest performs it's own recovery.  If firmware thaws a
passed-through PE because it's parent PE has been thawed (because it
was not passed through), re-freeze it.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05 11:55:44 +11:00

111 lines
2.8 KiB
C

/*
* EEH functionality support for VFIO devices. The feature is only
* available on sPAPR compatible platforms.
*
* Copyright Gavin Shan, IBM Corporation 2014.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <asm/eeh.h>
#define DRIVER_VERSION "0.1"
#define DRIVER_AUTHOR "Gavin Shan, IBM Corporation"
#define DRIVER_DESC "VFIO IOMMU SPAPR EEH"
/* We might build address mapping here for "fast" path later */
void vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
{
eeh_dev_open(pdev);
}
EXPORT_SYMBOL_GPL(vfio_spapr_pci_eeh_open);
void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)
{
eeh_dev_release(pdev);
}
EXPORT_SYMBOL_GPL(vfio_spapr_pci_eeh_release);
long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
unsigned int cmd, unsigned long arg)
{
struct eeh_pe *pe;
struct vfio_eeh_pe_op op;
unsigned long minsz;
long ret = -EINVAL;
switch (cmd) {
case VFIO_CHECK_EXTENSION:
if (arg == VFIO_EEH)
ret = eeh_enabled() ? 1 : 0;
else
ret = 0;
break;
case VFIO_EEH_PE_OP:
pe = eeh_iommu_group_to_pe(group);
if (!pe)
return -ENODEV;
minsz = offsetofend(struct vfio_eeh_pe_op, op);
if (copy_from_user(&op, (void __user *)arg, minsz))
return -EFAULT;
if (op.argsz < minsz || op.flags)
return -EINVAL;
switch (op.op) {
case VFIO_EEH_PE_DISABLE:
ret = eeh_pe_set_option(pe, EEH_OPT_DISABLE);
break;
case VFIO_EEH_PE_ENABLE:
ret = eeh_pe_set_option(pe, EEH_OPT_ENABLE);
break;
case VFIO_EEH_PE_UNFREEZE_IO:
ret = eeh_pe_set_option(pe, EEH_OPT_THAW_MMIO);
break;
case VFIO_EEH_PE_UNFREEZE_DMA:
ret = eeh_pe_set_option(pe, EEH_OPT_THAW_DMA);
break;
case VFIO_EEH_PE_GET_STATE:
ret = eeh_pe_get_state(pe);
break;
case VFIO_EEH_PE_RESET_DEACTIVATE:
ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE, true);
break;
case VFIO_EEH_PE_RESET_HOT:
ret = eeh_pe_reset(pe, EEH_RESET_HOT, true);
break;
case VFIO_EEH_PE_RESET_FUNDAMENTAL:
ret = eeh_pe_reset(pe, EEH_RESET_FUNDAMENTAL, true);
break;
case VFIO_EEH_PE_CONFIGURE:
ret = eeh_pe_configure(pe);
break;
case VFIO_EEH_PE_INJECT_ERR:
minsz = offsetofend(struct vfio_eeh_pe_op, err.mask);
if (op.argsz < minsz)
return -EINVAL;
if (copy_from_user(&op, (void __user *)arg, minsz))
return -EFAULT;
ret = eeh_pe_inject_err(pe, op.err.type, op.err.func,
op.err.addr, op.err.mask);
break;
default:
ret = -EINVAL;
}
}
return ret;
}
EXPORT_SYMBOL_GPL(vfio_spapr_iommu_eeh_ioctl);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);