kvm/x86: Hyper-V kvm exit

A new vcpu exit is introduced to notify the userspace of the
changes in Hyper-V SynIC configuration triggered by guest writing to the
corresponding MSRs.

Changes v4:
* exit into userspace only if guest writes into SynIC MSR's

Changes v3:
* added KVM_EXIT_HYPERV types and structs notes into docs

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index bab47b61d2b0..f608e170ba3d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -393,6 +393,7 @@ struct kvm_vcpu_hv {
         u64 hv_vapic;
         s64 runtime_offset;
         struct kvm_vcpu_hv_synic synic;
+        struct kvm_hyperv_exit exit;
 };
 
 struct kvm_vcpu_arch {