On 30/06/15 15:26, Daniel P. Berrange wrote:
On Tue, Jun 30, 2015 at 02:33:18PM +0300, Denis V. Lunev wrote:
Windows 2012 guests can notify hypervisor about occurred guest crash
(Windows bugcheck(BSOD)) by writing specific Hyper-V msrs. This patch does
handling of this MSR's by KVM and sending notification to user space that
allows to gather Windows guest crash dump by QEMU/LIBVIRT.
The idea is to provide functionality equal to pvpanic device without
QEMU guest agent for Windows.
That's nice - do you know if the Linux kernel (or any other non-Win2k12
kernels) have support for notifying hypevisors via this Hyper-V msr,
when running as a guest ?
Regards,
Daniel
Linux for sure is able to do that if configured to run
on top of Hyper-V
drivers/hv/vmbus_drv.c:
static 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;
}
Regards,
Den
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