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authorRoman Kagan <rkagan@virtuozzo.com>2018-02-01 16:48:32 +0300
committerRadim Krčmář <rkrcmar@redhat.com>2018-03-06 18:40:36 +0100
commitfaeb7833eee0d6afe0ecb6bdfa6042556c2c352e (patch)
tree894003ec025273ac159e9a57f9fc98c2dac180e0 /arch/x86/kvm/hyperv.h
parentcbc0236a4b3e6a64f5b8bee27b530c7f8bee8d56 (diff)
downloadlinux-faeb7833eee0d6afe0ecb6bdfa6042556c2c352e.tar.bz2
kvm: x86: hyperv: guest->host event signaling via eventfd
In Hyper-V, the fast guest->host notification mechanism is the SIGNAL_EVENT hypercall, with a single parameter of the connection ID to signal. Currently this hypercall incurs a user exit and requires the userspace to decode the parameters and trigger the notification of the potentially different I/O context. To avoid the costly user exit, process this hypercall and signal the corresponding eventfd in KVM, similar to ioeventfd. The association between the connection id and the eventfd is established via the newly introduced KVM_HYPERV_EVENTFD ioctl, and maintained in an (srcu-protected) IDR. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Reviewed-by: David Hildenbrand <david@redhat.com> [asm/hyperv.h changes approved by KY Srinivasan. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'arch/x86/kvm/hyperv.h')
-rw-r--r--arch/x86/kvm/hyperv.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index cc2468244ca2..837465d69c6d 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -90,5 +90,6 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
void kvm_hv_init_vm(struct kvm *kvm);
void kvm_hv_destroy_vm(struct kvm *kvm);
+int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args);
#endif