Hi,
In the pci_unplug() (dpdk/drivers/bus/pci/pci_common.c), why do we call
rte_devargs_remove() to remove the saved device args? That looks a defect to me, since
that’ll result in the hot removed device failed to be detected when it’s plugged back
(when white list option was provided), the situation is described following:
1. App starts with white list option provided, let’s suppose the device in white list
is: 0000:81:00.0;
2. rte_devargs_add() is called to add this device arg on rte_eal_init();
3. Issue “echo 1 > /sys/bus/pci/devices/0000\:81\:00.0/remove” to hot remove the
device;
4. pci_unplug() is called to remove the device, and rte_devargs_remove() is called, so
this device arg for white list is remove too;
5. Issue “echo 1 > /sys/bus/pci/rescan” then “PCI_WHITELIST=”0000:81:00.0”
spdk/script/setup.sh” to do hot plug;
6. In pci_scan_one(), new dev is generated, however, the dev->device.devargs is set
NULL since the device args has been removed on device unplug;
7. rte_pci_probe() does white list scan, however, it unexpectedly skips the device
because the devargs of the device is NULL now;
I don’t fully understand the DPDK code, but this rte_devargs_remove() in pci_unplug()
doesn’t make sense to me (when I commented it out, seems everything will work as
expected). Is this a glitch or I missed anything?
Thanks
-Niu
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