From: Nick Meier <nme...@microsoft.com> 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 <nme...@microsoft.com> Signed-off-by: K. Y. Srinivasan <k...@microsoft.com> --- drivers/hv/hyperv_vmbus.h | 11 +++++++++++ drivers/hv/vmbus_drv.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+), 0 deletions(-) diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index b055e53..88af4ec 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -49,6 +49,17 @@ enum hv_cpuid_function { HVCPUID_IMPLEMENTATION_LIMITS = 0x40000005, }; +#define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE 0x400 + +#define HV_X64_MSR_CRASH_P0 0x40000100 +#define HV_X64_MSR_CRASH_P1 0x40000101 +#define HV_X64_MSR_CRASH_P2 0x40000102 +#define HV_X64_MSR_CRASH_P3 0x40000103 +#define HV_X64_MSR_CRASH_P4 0x40000104 +#define HV_X64_MSR_CRASH_CTL 0x40000105 + +#define HV_CRASH_CTL_CRASH_NOTIFY 0x8000000000000000 + /* 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 f84ce5e..6cac44c 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; -- 1.7.4.1 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
