On Wed, Dec 03, 2014 at 09:07:27PM -0600, Nathan Fontenot wrote: > On 12/01/2014 10:26 PM, Greg KH wrote: > > On Mon, Dec 01, 2014 at 09:41:03AM -0600, Nathan Fontenot wrote: > >> On 11/26/2014 09:12 PM, Benjamin Herrenschmidt wrote: > >>> Hi Greg, > >>> > >>> So Nathan is working on a patch series to cleanup and improve our > >>> "DLPAR" infrastructure which is basically our hotplug mechanism when > >>> running under the PowerVM (aka pHyp) and KVM hypervisors. > >> > >> The cleanup to the dlpar infrastructure will move the entire operation > >> of hotplugging a device to the kernel instead of doing it partially in > >> userspace and partially in the kernel as is currently done. > >> > >>> > >>> I'll let Nathan give you a bit more details/background and answer > >>> subsequent question you might have as this is really his area of > >>> expertise. > >>> > >>> To cut a long story short, we need a sysfs file that allows our > >>> userspace tools to notify the kernel of hotplug events coming from > >>> the management console (which talks to userspace daemons using a > >>> proprietary protocol) to "initiate" the hotplug operations, which in > >>> turn get dispatched internally in the kernel to the right subsystem > >>> (memory, cpu, pci, ...) based on the resource type. > >>> > >>> On IRC, Greg suggested /sys/firmware and /sys/hypervisor which both > >>> look like a reasonable option to me, probably better than dlpar... > >> > >> For PowerVM systems we need this sysfs file to deliver what is > >> essentially a binary blob (specifically a rtas error log) to the > >> kernel. The current patch set is creating /sys/kernel/dlpar. As Ben > >> mentioned we would like your input on what would be the proper place > >> to create this file. > > > > And what is the kernel supposed to do with such a binary blob? Parse > > it? Or pass it to something else? > > The kernel will parse it and perform the requested hotplug operation.
Oh I was hoping you would not say that :( Seriously? Parsing binary blobs from userspace? Don't do that, you know better. greg k-h _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
