[Devel] [PATCH RHEL7 COMMIT] ms/kvm/x86: add sending hyper-v crash notification to user space

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.8.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-229.7.2.vz7.8.2
------>
commit 68d3bb61b238c5fdac105590539600cd276fa95d
Author: Andrey Smetanin <asmetanin at virtuozzo.com>
Date:   Fri Oct 2 12:19:35 2015 +0400

    ms/kvm/x86: add sending hyper-v crash notification to user space
    
    Sending of notification is done by exiting vcpu to user space
    if KVM_REQ_HV_CRASH is enabled for vcpu. At exit to user space
    the kvm_run structure contains system_event with type
    KVM_SYSTEM_EVENT_CRASH to notify about guest crash occurred.
    
    ms commit - 2ce7918990641b07e70e1b25752d666369e2016e
    
    Signed-off-by: Andrey Smetanin <asmetanin at virtuozzo.com>
    
    Signed-off-by: Denis V. Lunev <den at openvz.org>
    Reviewed-by: Peter Hornyack <peterhornyack at google.com>
    CC: Paolo Bonzini <pbonzini at redhat.com>
    CC: Gleb Natapov <gleb at kernel.org>
    Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
---
 Documentation/virtual/kvm/api.txt | 1 +
 arch/x86/kvm/x86.c                | 6 ++++++
 include/uapi/linux/kvm.h          | 1 +
 3 files changed, 8 insertions(+)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 9ae0e53..f919ff6 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2687,6 +2687,7 @@ should put the acknowledged interrupt vector into the 'epr' field.
 		struct {
 #define KVM_SYSTEM_EVENT_SHUTDOWN       1
 #define KVM_SYSTEM_EVENT_RESET          2
+#define KVM_SYSTEM_EVENT_CRASH          3
 			__u32 type;
 			__u64 flags;
 		} system_event;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eeb63f7..db1017b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5787,6 +5787,12 @@ 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;
+			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 c35227f..d2ea15d 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -306,6 +306,7 @@ struct kvm_run {
 		struct {
 #define KVM_SYSTEM_EVENT_SHUTDOWN       1
 #define KVM_SYSTEM_EVENT_RESET          2
+#define KVM_SYSTEM_EVENT_CRASH          3
 			__u32 type;
 			__u64 flags;
 		} system_event;