From 96c1d0581d00f7abe033350edb021a9d947d8d81 Mon Sep 17 00:00:00 2001 From: Nick Meier Date: Sat, 28 Feb 2015 11:39:01 -0800 Subject: Drivers: hv: vmbus: Add support for VMBus panic notifier handler 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 --- drivers/hv/vmbus_drv.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'drivers/hv/vmbus_drv.c') 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 #include #include +#include +#include #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; -- cgit v1.2.3