Gleb, Paolo, Marcelo, here are some low level changes to kvm on s390 that we have been cooking for a while now. Patch "s390/pgtable: fix ipte notify bit" will go via Martins tree into 3.10, but is included to reduce the amount of merge conflicts. Patch "s390: fix gmap_ipte_notifier vs. software dirty pages" will also go via Martins tree into 3.10 and it fixes a hang with heavy host paging and KVM. This is optional for merging, but makes testing on kvm/next easier. This series addresses 2 problems: - paging of guest prefix page - RCU timeouts The first problem is basically that we must not have the host pte invalid or r/o for the guest prefix pages. (everything else has fully nested paging but the prefix page must not cause host faults). It is not enough to pin the page, also the pte has to be r/w all the time. Mlocking is not enough due to memory compaction, malicious unmapping etc. We use the existing callback mechanism of the s390 page table functions to kick guests out of SIE and hold them until this is done. We cant use the existing kick functions since we must hold a pgste lock while we wait for SIE to exit and IPIs might dead lock. The second problem is that with KVM on s390 we have seen very long RCU stalls due to SIE not exiting on interrupts. Instead of returning to SIE, we now force an exit into the kvm module, which then does the guest exit/enter magic, fixing rcu. The whole bunch is probably too complex for 3.10, so please queue for 3.11 Christian Borntraeger (5): s390/pgtable: fix ipte notify bit s390/kvm: Mark if a cpu is in SIE s390/kvm: Provide a way to prevent reentering SIE s390/kvm: Kick guests out of sie if prefix page host pte is touched s390: fix gmap_ipte_notifier vs. software dirty pages Martin Schwidefsky (3): s390/kvm: fix psw rewinding in handle_skey s390/kvm: rename RCP_xxx defines to PGSTE_xxx s390/kvm: avoid automatic sie reentry arch/s390/include/asm/kvm_host.h | 8 +++- arch/s390/include/asm/pgtable.h | 83 +++++++++++++++++++--------------------- arch/s390/kernel/asm-offsets.c | 3 ++ arch/s390/kernel/entry64.S | 80 ++++++++++++++++++-------------------- arch/s390/kvm/intercept.c | 39 +------------------ arch/s390/kvm/kvm-s390.c | 81 ++++++++++++++++++++++++++++++++++++++- arch/s390/kvm/kvm-s390.h | 5 +++ arch/s390/kvm/priv.c | 3 +- arch/s390/mm/pgtable.c | 5 +-- 9 files changed, 179 insertions(+), 128 deletions(-) -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
