1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 2b7b51d264f1..526fa8b19cda 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -37,6 +37,8 @@
 #include <asm/hyperv.h>
 #include <asm/hypervisor.h>
 #include <asm/mshyperv.h>
+#include <linux/notifier.h>
+#include <linux/ptrace.h>
 #include "hyperv_vmbus.h"
 
 static struct acpi_device  *hv_acpi_dev;
@@ -45,6 +47,31 @@ static struct tasklet_struct msg_dpc;
 static struct completion probe_event;
 static int irq;
 
+
+int hyperv_panic_event(struct notifier_block *nb,
+                        unsigned long event, void *ptr)
+{
+        struct pt_regs *regs;
+
+        regs = current_pt_regs();
+
+        wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
+        wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
+        wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
+        wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
+        wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
+
+        /*
+         * Let Hyper-V know there is crash data available
+         */
+        wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block hyperv_panic_block = {
+        .notifier_call = hyperv_panic_event,
+};
+
 struct resource hyperv_mmio = {
         .name  = "hyperv mmio",
         .flags = IORESOURCE_MEM,
@@ -795,6 +822,15 @@ static int vmbus_bus_init(int irq)
                 goto err_alloc;
 
         hv_cpu_hotplug_quirk(true);
+
+        /*
+         * Only register if the crash MSRs are available
+         */
+        if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
+                atomic_notifier_chain_register(&panic_notifier_list,
+                                               &hyperv_panic_block);
+        }
+
         vmbus_request_offers();
 
         return 0;