diff options
| author | zhenwei pi <pizhenwei@bytedance.com> | 2021-01-10 19:53:58 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-27 14:28:17 +0100 |
| commit | 8d6da6575ffec171161d36a06c015142b0049637 (patch) | |
| tree | bd1bdd45d6f88de6d2b20f133a0f69957af48093 /drivers/misc/pvpanic.c | |
| parent | 487709fa1be2f27aa8e7de6c60587b4302a21467 (diff) | |
| download | lwn-8d6da6575ffec171161d36a06c015142b0049637.tar.gz lwn-8d6da6575ffec171161d36a06c015142b0049637.zip | |
misc: pvpanic: introduce events device attribue
Suggested by Paolo & Greg, add 'events' device attribute that can be
used to limit which capabilities the driver uses.
Finally, the pvpanic guest driver works by the limitation of both
device capability and user setting.
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20210110115358.79100-3-pizhenwei@bytedance.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/pvpanic.c')
| -rw-r--r-- | drivers/misc/pvpanic.c | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c index 80cdfa8f951a..b1e4922a7fda 100644 --- a/drivers/misc/pvpanic.c +++ b/drivers/misc/pvpanic.c @@ -20,6 +20,7 @@ static void __iomem *base; static unsigned int capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED; +static unsigned int events; static ssize_t capability_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -28,8 +29,34 @@ static ssize_t capability_show(struct device *dev, } static DEVICE_ATTR_RO(capability); +static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%x", events); +} + +static ssize_t events_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned int tmp; + int err; + + err = kstrtouint(buf, 16, &tmp); + if (err) + return err; + + if ((tmp & capability) != tmp) + return -EINVAL; + + events = tmp; + + return count; + +} +static DEVICE_ATTR_RW(events); + static struct attribute *pvpanic_dev_attrs[] = { &dev_attr_capability.attr, + &dev_attr_events.attr, NULL }; ATTRIBUTE_GROUPS(pvpanic_dev); @@ -41,7 +68,7 @@ MODULE_LICENSE("GPL"); static void pvpanic_send_event(unsigned int event) { - if (event & capability) + if (event & capability & events) iowrite8(event, base); } @@ -90,6 +117,7 @@ static int pvpanic_mmio_probe(struct platform_device *pdev) /* initlize capability by RDPT */ capability &= ioread8(base); + events = capability; if (capability) atomic_notifier_chain_register(&panic_notifier_list, |