From: Nick Meier
Hyper-V allows a guest to notify the Hyper-V host that a panic
condition occured. This notification can include up to five 64
bit values. These 64 bit values are written into crash MSRs.
Once the data has been written into the crash MSRs, the host is
then notified by writing into a Crash Control MSR. On the Hyper-V
host, the panic notification data is captured in the Windows Event
log as a 18590 event.
Crash MSRs are defined in appendix H of the Hypervisor Top Level
Functional Specification. At the time of this patch, v4.0 is the
current functional spec. The URL for the v4.0 document is:
http://download.microsoft.com/download/A/B/4/AB43A34E-BDD0-4FA6-BDEF-79EEF16E880B/Hypervisor
Top Level Functional Specification v4.0.docx
Signed-off-by: Nick Meier
Signed-off-by: K. Y. Srinivasan
Signed-off-by: Greg Kroah-Hartman
(backported from commit 96c1d0581d00f7abe033350edb021a9d947d8d81)
Signed-off-by: Joseph Salisbury
---
drivers/hv/hyperv_vmbus.h | 11 +++
drivers/hv/vmbus_drv.c| 40
2 files changed, 51 insertions(+)
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index e055176..3f39c73 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -49,6 +49,17 @@ enum hv_cpuid_function {
HVCPUID_IMPLEMENTATION_LIMITS = 0x4005,
};
+#define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE 0x400
+
+#define HV_X64_MSR_CRASH_P0 0x4100
+#define HV_X64_MSR_CRASH_P1 0x4101
+#define HV_X64_MSR_CRASH_P2 0x4102
+#define HV_X64_MSR_CRASH_P3 0x4103
+#define HV_X64_MSR_CRASH_P4 0x4104
+#define HV_X64_MSR_CRASH_CTL 0x4105
+
+#define HV_CRASH_CTL_CRASH_NOTIFY 0x8000
+
/* Define version of the synthetic interrupt controller. */
#define HV_SYNIC_VERSION (1)
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 077bb1b..66168c3 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -36,6 +36,8 @@
#include
#include
#include
+#include
+#include
#include "hyperv_vmbus.h"
static struct acpi_device *hv_acpi_dev;
@@ -44,6 +46,36 @@ 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,
+};
+EXPORT_SYMBOL_GPL(hyperv_mmio);
+
static int vmbus_exists(void)
{
if (hv_acpi_dev == NULL)
@@ -747,6 +779,14 @@ static int vmbus_bus_init(int irq)
if (ret)
goto err_alloc;
+ /*
+* 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;
--
2.1.0
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