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.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Peter Hornyack <peterhornyack@google.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index a7926a90156f64172897ca5a9ae562f7975701a7..a4ebcb712375478e9bb60a7652d49f4d46b9c978 100644 (file)
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -3277,6 +3277,7 @@ 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;
@@ -3296,6 +3297,10 @@ Valid values for 'type' are:
   KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM.
    As with SHUTDOWN, userspace can choose to ignore the request, or
    to schedule the reset to occur in the future and may call KVM_RUN again.
+  KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest
+   has requested a crash condition maintenance. Userspace can choose
+   to ignore the request, or to gather VM memory core dump and/or
+   reset/shutdown of the VM.
 
                /* Fix the size of the union. */
                char padding[256];

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cfa3e5a7d6bef5ca3e37428c54d091f134fce376..28076c266a9a3aee5f165509e76d2e85b26ae2dd 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6263,6 +6263,12 @@ 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/linux/kvm_host.h b/include/linux/kvm_host.h
index 1d917d9b7f12c765b2ab73a47123470693be2f74..51103f0feb7e21e6c4d8a525c5939551046a42f3 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -139,6 +139,7 @@ static inline bool is_error_page(struct page *page)
 #define KVM_REQ_DISABLE_IBS       24
 #define KVM_REQ_APIC_PAGE_RELOAD  25
 #define KVM_REQ_SMI               26
+#define KVM_REQ_HV_CRASH          27
 
 #define KVM_USERSPACE_IRQ_SOURCE_ID            0
 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID       1

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 716ad4ae4d4b10443f4618bd96e86a71fa521d78..9ef19ebd9df4b57e8bda211616db0205f6bd3054 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -317,6 +317,7 @@ 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;