在 2013-02-28四的 11:18 +0100，Vasilis Liaskovitis写道： > Hi, > > sorry for the delay. > On Tue, Feb 19, 2013 at 07:39:40PM -0300, Erlon Cruz wrote: > > On Tue, Dec 18, 2012 at 10:41 AM, Vasilis Liaskovitis < > > vasilis.liaskovi...@profitbricks.com> wrote: > > > > > This is v4 of the ACPI memory hotplug functionality. Only x86_64 target is > > > supported (both i440fx and q35). There are still several issues, but it's > > > been a while since v3 and I wanted to get some more feedback on the > > > current > > > state of the patchseries. > > > > > > > > We are working in memory hotplug functionality on pSeries machine. I'm > > wondering whether and how we can better integrate things. Do you think the > > DIMM abstraction is generic enough to be used in other machine types? > > I think the DimmDevice is generic enough but I am open to other suggestions. > > A related issue is that the patchseries uses a DimmBus to hot-add and > hot-remove > DimmDevice. Another approach that has been suggested is to use links<> between > DimmDevices and the dram controller device (piix4 or mch for pc and q35-pc > machines respectively). This would be more similar to the CPUState/qom > patches - see Andreas Färber's earlier reply to this thread. > > I think we should get some consensus from the community/maintainers before we > continue to integrate. > > I haven't updated the series for a while, but I can rework if there is a more > clear direction for the community. > > Another open issue is reference counting of memoryregions in qemu memory > model. In order to make memory hot-remove operations safe, we need to remove > a memoryregion after all users (e.g. both guest and block layer) have stopped > using it,
it seems it mostly up to the user who want to hot-(un)plug, if user want to un-plug a memory which is kernel's main memory, kernel will always run on it(never stop) unless power off. and if guest stops, all DIMMs should be safe to hot-remove, or else we should do something to let user can unlock all reference. > see discussion at > http://lists.gnu.org/archive/html/qemu-devel/2012-10/msg03986.html. There was > a > relevant ibm patchset > https://lists.gnu.org/archive/html/qemu-devel/2012-11/msg02697.html > but it was not merged. > > > > > > > > Overview: > > > > > > Dimm device layout is modeled with a normal qemu device: > > > > > > "-device dimm,id=name,size=sz,node=pxm,populated=on|off,bus=membus.0" > > > > > > > > How does this will handle the no-hotplugable memory for example the memory > > passed in '-m' parameter? > > The non-hotpluggable initial memory (-m) is currently not modelled at all as a > DimmDevice. We may want to model it though. > > thanks, > - Vasilis >
