[Qemu-devel] [PATCH 8/9] kvm/x86: add sending hyper-v crash notification to user space

["Denis V. Lunev" <den@openvz.org>]

From: Andrey Smetanin <asmetanin@virtuozzo.com>

Sending of notification is done by exiting vcpu to user space
if KVM_REQ_HV_CRASH is enabled for vcpu. kvm_run structure
will contains system_event with type KVM_SYSTEM_EVENT_CRASH
and flag KVM_SYSTEM_EVENT_FL_HV_CRASH to clarify that
crash occures inside Hyper-V based guest.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
---
 arch/x86/kvm/x86.c       | 8 ++++++++
 include/uapi/linux/kvm.h | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 47b7507..55a4b92 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6264,6 +6264,14 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 			vcpu_scan_ioapic(vcpu);
 		if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu))
 			kvm_vcpu_reload_apic_access_page(vcpu);
+		if (kvm_check_request(KVM_REQ_HV_CRASH, vcpu)) {
+			vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
+			vcpu->run->system_event.type = KVM_SYSTEM_EVENT_CRASH;
+			vcpu->run->system_event.flags =
+						KVM_SYSTEM_EVENT_FL_HV_CRASH;
+			r = 0;
+			goto out;
+		}
 	}
 
 	if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 716ad4a..eefb8b9 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -317,6 +317,8 @@ struct kvm_run {
 		struct {
 #define KVM_SYSTEM_EVENT_SHUTDOWN       1
 #define KVM_SYSTEM_EVENT_RESET          2
+#define KVM_SYSTEM_EVENT_CRASH          3
+#define KVM_SYSTEM_EVENT_FL_HV_CRASH    (1ULL << 0)
 			__u32 type;
 			__u64 flags;
 		} system_event;
-- 
2.1.4