Commit db3a4f0a authored by Mihai Carabas's avatar Mihai Carabas Committed by Greg Kroah-Hartman

misc/pvpanic: add PCI driver

Add support for pvpanic PCI device added in qemu [1]. At probe time, obtain the
address where to read/write pvpanic events and pass it to the generic handling
code. Will follow the same logic as pvpanic MMIO device driver. At remove time,
unmap base address and disable PCI device.

[1] https://github.com/qemu/qemu/commit/9df52f58e76e904fb141b10318362d718f470db2Signed-off-by: default avatarMihai Carabas <mihai.carabas@oracle.com>
Link: https://lore.kernel.org/r/1616597356-20696-4-git-send-email-mihai.carabas@oracle.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b3c0f877
What: /sys/devices/pci0000:00/*/QEMU0001:00/capability What: /sys/devices/pci0000:00/*/QEMU0001:00/capability for MMIO
/sys/bus/pci/drivers/pvpanic-pci/0000:00:0*.0/capability for PCI
Date: Jan 2021 Date: Jan 2021
Contact: zhenwei pi <pizhenwei@bytedance.com> Contact: zhenwei pi <pizhenwei@bytedance.com>
Description: Description:
...@@ -12,6 +13,7 @@ Description: ...@@ -12,6 +13,7 @@ Description:
https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/specs/pvpanic.txt https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/specs/pvpanic.txt
What: /sys/devices/pci0000:00/*/QEMU0001:00/events What: /sys/devices/pci0000:00/*/QEMU0001:00/events
/sys/bus/pci/drivers/pvpanic-pci/0000:00:0*.0/events for PCI
Date: Jan 2021 Date: Jan 2021
Contact: zhenwei pi <pizhenwei@bytedance.com> Contact: zhenwei pi <pizhenwei@bytedance.com>
Description: Description:
......
...@@ -17,3 +17,11 @@ config PVPANIC_MMIO ...@@ -17,3 +17,11 @@ config PVPANIC_MMIO
depends on HAS_IOMEM && (ACPI || OF) && PVPANIC depends on HAS_IOMEM && (ACPI || OF) && PVPANIC
help help
This driver provides support for the MMIO pvpanic device. This driver provides support for the MMIO pvpanic device.
config PVPANIC_PCI
tristate "pvpanic PCI device support"
depends on PCI && PVPANIC
help
This driver provides support for the PCI pvpanic device.
pvpanic is a paravirtualized device provided by QEMU which
forwards the panic events from the guest to the host.
...@@ -5,3 +5,4 @@ ...@@ -5,3 +5,4 @@
# Copyright (C) 2021 Oracle. # Copyright (C) 2021 Oracle.
# #
obj-$(CONFIG_PVPANIC_MMIO) += pvpanic.o pvpanic-mmio.o obj-$(CONFIG_PVPANIC_MMIO) += pvpanic.o pvpanic-mmio.o
obj-$(CONFIG_PVPANIC_PCI) += pvpanic.o pvpanic-pci.o
// SPDX-License-Identifier: GPL-2.0+
/*
* Pvpanic PCI Device Support
*
* Copyright (C) 2021 Oracle.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <uapi/misc/pvpanic.h>
#include "pvpanic.h"
#define PCI_VENDOR_ID_REDHAT 0x1b36
#define PCI_DEVICE_ID_REDHAT_PVPANIC 0x0011
MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>");
MODULE_DESCRIPTION("pvpanic device driver ");
MODULE_LICENSE("GPL");
static const struct pci_device_id pvpanic_pci_id_tbl[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_PVPANIC)},
{}
};
static ssize_t capability_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
return sysfs_emit(buf, "%x\n", pi->capability);
}
static DEVICE_ATTR_RO(capability);
static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
return sysfs_emit(buf, "%x\n", pi->events);
}
static ssize_t events_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
unsigned int tmp;
int err;
err = kstrtouint(buf, 16, &tmp);
if (err)
return err;
if ((tmp & pi->capability) != tmp)
return -EINVAL;
pi->events = tmp;
return count;
}
static DEVICE_ATTR_RW(events);
static struct attribute *pvpanic_pci_dev_attrs[] = {
&dev_attr_capability.attr,
&dev_attr_events.attr,
NULL
};
ATTRIBUTE_GROUPS(pvpanic_pci_dev);
static int pvpanic_pci_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
struct device *dev = &pdev->dev;
struct pvpanic_instance *pi;
void __iomem *base;
int ret;
ret = pci_enable_device(pdev);
if (ret < 0)
return ret;
base = pci_iomap(pdev, 0, 0);
if (IS_ERR(base))
return PTR_ERR(base);
pi = kmalloc(sizeof(*pi), GFP_ATOMIC);
if (!pi)
return -ENOMEM;
pi->base = base;
pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
/* initlize capability by RDPT */
pi->capability &= ioread8(base);
pi->events = pi->capability;
dev_set_drvdata(dev, pi);
return pvpanic_probe(pi);
}
static void pvpanic_pci_remove(struct pci_dev *pdev)
{
struct pvpanic_instance *pi = dev_get_drvdata(&pdev->dev);
pvpanic_remove(pi);
iounmap(pi->base);
kfree(pi);
pci_disable_device(pdev);
}
static struct pci_driver pvpanic_pci_driver = {
.name = "pvpanic-pci",
.id_table = pvpanic_pci_id_tbl,
.probe = pvpanic_pci_probe,
.remove = pvpanic_pci_remove,
.driver = {
.dev_groups = pvpanic_pci_dev_groups,
},
};
module_pci_driver(pvpanic_pci_driver);
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