KY Srinivasan <kys@xxxxxxxxxxxxx> writes: >> -----Original Message----- >> From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] >> Sent: Thursday, August 11, 2016 2:17 AM >> To: KY Srinivasan <kys@xxxxxxxxxxxxx> >> Cc: devel@xxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Haiyang Zhang >> <haiyangz@xxxxxxxxxxxxx> >> Subject: Re: [PATCH 0/2] Drivers: hv: vmbus: make bus ids in sysfs persistent >> >> KY Srinivasan <kys@xxxxxxxxxxxxx> writes: >> >> >> -----Original Message----- >> >> From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] >> >> Sent: Tuesday, August 9, 2016 1:46 AM >> >> To: devel@xxxxxxxxxxxxxxxxxxxxxx >> >> Cc: linux-kernel@xxxxxxxxxxxxxxx; Haiyang Zhang >> >> <haiyangz@xxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx> >> >> Subject: [PATCH 0/2] Drivers: hv: vmbus: make bus ids in sysfs >> >> persistent >> >> >> >> Bus ids for VMBus devices in /sys/bus/vmbus/devices/ are not >> >> guaranteed to be persistent across reboot or kernel restart and this >> >> causes problems for some tools. E.g. kexec tools use these ids to identify >> NIC on kdump. >> >> Fix the issue by using relid from channel offer as the unique id >> >> instead of an auto incremented counter. >> > >> > Relids are not persistent. It is only valid between a channel offer >> > message and a relid released message (or an unload or initiate contact >> > message, which invalidates all channels). This is an opaque number >> > that the root generates and uses to track channels. There is no >> > guarantee that the same type of channel (networking, storage, etc) >> > will get the same relid on each reboot. >> > >> >> Thanks for the info, >> >> can we use device_id (offermsg.offer.if_instance.b) instead? > > I think you could; I am going to verify and get back to you on this. Thanks! > Sometime back I removed all the non-determinism in the vmbus device > ID generation. Now, the current scheme of generating the device IDs does > result in persistent IDs across boot (as long as the host presents the devices > to the guest in the same order across boots). Do you have this fix? Yes, I think I do. The issue I'm trying to address happens rearly on kdump when we get devices present to us in a different order. -- Vitaly _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
