| Message ID | 20181130143215.69496-1-mimu@linux.ibm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | KVM: s390: make use of the GIB | expand |
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 >
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