FWIW, Assuming that Michael addresses the small comments of Cornelia I will apply the next version to kvms390/next. As we touch common s390/cio/ code this will be a topic branch that I will merge. In case of conflicts Martin can then also merge this. If there are no conflicts then this will only go via the kvms390 tree. On 30.11.2018 15:32, Michael Mueller wrote: > The Guest Information Area (GIB) and its mechanics is part of > the AIV facility. It provides hardware support to process > Adapter Interruptions (AI) for pagable storage mode guests. > > Whenever a guest cannot process an AI because none of its > vcpus is running in SIE context, a GIB alert interruption is > sent to and handled by the host program to dispatch a vcpu of > the respective guest. > > Eventually, the AI is handled by the guest. > > v3->v4: > The central change of v4 is that the metric "vcpus_in_sie" > has been dropped. A least agressive IAM restore strategy > is being followed now. The consequence is that potentially > more GAL interruptions are to be handled by the host program. > The assuption as made that as soon the first vcpu is trying > to go into wait state, this could be the last vcpu being > open for I/O interruptions. Thus, to not loose the initiative > to deliver I/O interruptions as soon as possible, the IAM > is restored. Adding better heuristics can be done in future. > > I expect this to be the last version of the series. > > patch 01/12: Kernel msg now printed when FLIC fails > to register during arch inititialization. > patch 03/12: Commit message slightly changed with the > hint that gib initialization is called > by last patch of this serias. > patch 09/12: IAM now restored during kvm_s390_handle_wait() > patch 10/12: gib destroy case now handled upon unsuccessful > arch inititialization. > > All other patches are unchanged. > > v2->v3: > patch 01/12: Fixes a resource dealocation issue upon > unsuccessful exit from kvm_arch_init(). > It is relevant for patch 11/12 as well. > patch 08/12: The function process_gib_alert_list() has > been rewritten to reduce the number of GAL > interruptions on the host for many guest > scenarios. > patch 10/12: The IAM is now never cleared before SIE entry. > It will be cleared by millicode as soon the > first guest interruption is made pending and > not directly processed in SIE. The IAM gets > restored as soon a vm is idle, i.e. no vcpu > of that guest is in SIE context anymore. > patch 11/12: now integrates with new patch 01/12 > patch 12/12: This patch is just experimental and shall not > be part of the final series. > > The first patch of series v2: "leave AIs in IPM of GISA > during vcpu_pre_run()" has been dropped. > > All other patches are unchanged. > > v1->v2: > patch 01/12: New patch. Tt can go also standalone without the > rest of the GIB series presented here but is a > requirement > patch 03/12: kvm_s390_gib_init() now has a return code > patch 06/12: unlink_gib_alert_list() now uses cmpxchg() instead > of atomic_xchg() > patch 08/12: New patch. Foctors out __find_vcpu_for_floating_irq() > patch 09/12: process_gib_alert_list() has been simplified > the GISA clear/destroy cases have been removed > patch 11/12: kvm_s390_gisa_clear/destroy() now clear the IAM > and process the alert list directly > The IAM now gets restored in vcpu_post_run() only if > the GISA is not in alert list > patch 12/12: during kvm_arch_init() now the return code of > kvm_s390_gib_init() is honored. > > All other patches are unchanged. > > Michael Mueller (10): > KVM: s390: unregister debug feature on failing arch init > s390/cio: add function chsc_sgib() > KVM: s390: add the GIB and its related life-cyle functions > KVM: s390: factor out nullify_gisa() > KVM: s390: add kvm reference to struct sie_page2 > KVM: s390: factor out __find_vcpu_for_floating_irq() > KVM: s390: add function process_gib_alert_list() > KVM: s390: add functions to (un)register GISC with GISA > KVM: s390: add and wire function gib_alert_irq_handler() > KVM: s390: start using the GIB > > Documentation/kmsg/s390/kvm | 24 +++++ > arch/s390/include/asm/cio.h | 1 + > arch/s390/include/asm/irq.h | 1 + > arch/s390/include/asm/isc.h | 1 + > arch/s390/include/asm/kvm_host.h | 19 +++- > arch/s390/kernel/irq.c | 1 + > arch/s390/kvm/interrupt.c | 214 +++++++++++++++++++++++++++++++++++++-- > arch/s390/kvm/kvm-s390.c | 27 ++++- > arch/s390/kvm/kvm-s390.h | 7 ++ > drivers/s390/cio/chsc.c | 37 +++++++ > drivers/s390/cio/chsc.h | 1 + > 11 files changed, 318 insertions(+), 15 deletions(-) > create mode 100644 Documentation/kmsg/s390/kvm >
