Make it possible for guests using Hyper-V emulation to do guest->host notification via EVENT_SIGNAL hypercall without a user exit. Special thanks to David Hildenbrand for going through the spec with me to figure out the desired behavior. v8 -> v9: - pass events with non-zero FlagNumber to userspace v7 -> v8: - rebase to latest master v6 -> v7: - reject non-zero flag number as invalid - adjust error returns to better match the spec v5 -> v6: - drop unnecessary srcu_read_lock/unlock, and clean up after that v4 -> v5: - fix block comment formatting v3 -> v4: - switch to kvm_vcpu_read_guest and take srcu_read_lock around it - rework and document the interpretation of the hypercall parameter - merge !fast version into kvm_hvcall_signal_event for brevity v2 -> v3: - expand docs on allowed values and return codes - fix uninitialized return - style fixes v1 -> v2: - make data types consistent - get by without the recently dropped struct hv_input_signal_event - fix subject prefixes Roman Kagan (2): kvm: x86: factor out kvm.arch.hyperv (de)init kvm: x86: hyperv: guest->host event signaling via eventfd Documentation/virtual/kvm/api.txt | 31 ++++++++++ arch/x86/include/asm/kvm_host.h | 2 + arch/x86/include/uapi/asm/hyperv.h | 2 + arch/x86/kvm/hyperv.h | 4 ++ include/uapi/linux/kvm.h | 13 +++++ arch/x86/kvm/hyperv.c | 112 ++++++++++++++++++++++++++++++++++++- arch/x86/kvm/x86.c | 13 ++++- 7 files changed, 175 insertions(+), 2 deletions(-) -- 2.14.3
