This patch will forward the yield_to hypercall (diag9c) if in the host the target CPU is also not running. As we do not yet have performance data (and recommendations) the default is turned off, but this can be changed during runtime. The documentation notation for the titles is kept coherent with the other DIAGNOSE entries using the zVM notation DIAGNOSE 'X'9C, While in the explanation part we use the standard Linux notation DIAGNOSE 0x9c. Regards, Pierre Pierre Morel (1): KVM: s390: diag9c (directed yield) forwarding Documentation/virt/kvm/s390-diag.rst | 33 ++++++++++++++++++++++++++++ arch/s390/include/asm/kvm_host.h | 1 + arch/s390/include/asm/smp.h | 1 + arch/s390/kernel/smp.c | 1 + arch/s390/kvm/diag.c | 31 +++++++++++++++++++++++--- arch/s390/kvm/kvm-s390.c | 6 +++++ arch/s390/kvm/kvm-s390.h | 8 +++++++ 7 files changed, 78 insertions(+), 3 deletions(-) -- 2.17.1 Changelog: >From v3: - rewording of the commit message (Connie) - great rewording of the documentation (Connie) - Keep smp_yield_cpu symbol GPL (Connie) - More explicit diag9c_forwarding_hz parameter description (Connie) >From v2: - update overrun comparison, avoid comparison on unsigned (Pierre) >From v1: - more precise comments (Connie) - Documentation (Janosch)
