Hi David, > > Hi Pankaj, > > I have a prototype (new one for virtio-mem I was working on over the last > weeks) for exactly what you need. I basically factored out the notion of a > memory device. So also virtio devices can be memory devices and get > recognized e.g. in formerly known pc_dimm_get_free_address(), so it works > out nicely with ordinary memory hotplug and such. Nice. This is very useful re-factoring. > > Guess your main problem right now is that you don‘t create a memory slot > properly. But I also have code for that that you can built onto. sure. > > I‘m right now in Sri Lanka on vacation, I‘ll be back on 23. September and > will send you the link to a branch with the prototype asap. Cool. Enjoy your vacation and thanks for the reply. Best regards, Pankaj > > Thanks, > > David / dhildenb / david@xxxxxxxxxx > > Von meinem iPhone gesendet > > > Am 14.03.2018 um 10:36 schrieb Pankaj Gupta <pagupta@xxxxxxxxxx>: > > > > > > > > Hi, > > > > > > I am implementing 'virtio-pmem' as a mechanism to > > flush guest writes with 'fake DAX' flushing interface. > > > > Below is the high level details of components: > > > > 1] 'virtio-pmem' device expose guest physical address > > details(start, len). > > > > 2] 'virtio-pmem' driver in guest discovers this > > information and configures 'libnvdimm'. Guest 'pmem' > > driver works on this memory range. > > > > 3] Guest 'pmem' driver uses 'virtio-pmem' PV driver to > > send flush commands. > > > > > > I need suggestion implementing part 1] > > > > * When tried with 'hotplug_memory.base' address as guest physical > > address, I am facing 'EPT_MISCONFIG' errors when pmem does mkfs. > > After digging more it looks like address range I am using as guest > > physical address is either already mapped as MMIO or reserved. > > Though Guest hot-plugs this physical address into its virtual > > memory range when guest tries to read/write the memory KVM cannot > > translate the address and throw 'EPT_MISCONFIG' error. > > > > * While I am trying to get the appropriate guest physical address > > which is free, I could see memory 'pc_dimm_memory_plug' code > > has a function 'pc_dimm_get_free_addr' which works with 'PC DIMM' > > class. As I am using 'VIRTIO', there is no way AFAIK this function > > can be used by VIRTIO or my PV device code. > > > > > > I need ideas to get the free guest physical address from my PV > > device code so that we can use this range in guest address space. > > > > Find below pointer to previous discussion: > > > > https://marc.info/?l=kvm&m=151629709903946&w=2 > > > > Thanks, > > Pankaj > > >
