On Mon, Jan 18, 2016 at 04:44:38PM +1100, David Gibson wrote: > Here is a draft qemu implementation of my proposed PAPR extension for > allowing runtime resizing of a KVM/ppc64 guest's hash page table. > That in turn will allow for more flexible memory hotplug. > > This should work with the guest kernel side patches I also posted > recently [1]. > > Still required to make this into a full implementation: > * Guest needs to auto-resize HPT on memory hotplug events > > * qemu needs to allocate HPT size based on current rather than > maximum memory if the guest is HPT resize aware > > * KVM host side implementation > > * PAPR standardization
So with the current patchset (QEMU and guest kernel changes), I should be able to change the HTAB size of a PR guest right ? I see the below failure though: [root@localhost ~]# cat /sys/kernel/debug/powerpc/pft-size 24 [root@localhost ~]# echo 26 > /sys/kernel/debug/powerpc/pft-size [ 65.996845] lpar: Attempting to resize HPT to shift 26 [ 65.996845] lpar: Attempting to resize HPT to shift 26 [ 66.113596] lpar: HPT resize to shift 26 complete (109 ms / 6 ms) [ 66.113596] lpar: HPT resize to shift 26 complete (109 ms / 6 ms) PR guest just hangs here while I see tons of below messages in the 1st level guest: KVM can't copy data from 0x3fff99e91400! ... Couldn't emulate instruction 0x00000000 (op 0 xop 0) kvmppc_handle_exit_pr: emulation at 700 failed (00000000) Regards, Bharata.
