RE: [Regression, bisected]a3e06bbe8445f57eb949e6474c5a9b30f24d2057: KVM: emulate lapic tsc deadlinetimer for guest"

From: Liu, Jinsong
Date: Mon Dec 12 2011 - 01:15:30 EST


Alexey Zaytsev wrote:
> Hi.
>
> After a recent change, qemu --enable-kvm (both 0.15.92 and 1.0) fails
> to boot illumos. The OS gets stuck pretty late in the boot process,
> without any hints from the guest. MDB (the illumos kenrnel debugger)
> failed to clarify the situation at once, the kernel seems to be stuck
> idling. I've bisected the problem to commit
> a3e06bbe8445f57eb949e6474c5a9b30f24d2057. Please let me know if you
> need me to collect any debug information or test any patches.

Alexey,

Does illumos use tsc deadline timer? and do you run it at Intel platform?

If yes, would you please help me to collect debug information by add some printk points at kvm tsc deadline timer logic? currently I totally have no clue to figure out what the issue root from :)
and, would you please check illumos tsc deadline timer logic by confirm whether illumos
1). Enumerate tsc deadline timer capability by CPUID;
2). Enable tsc deadline timer mode by lapic MMIO;
3). Start tsc deadline timer by WRMSR;

Thanks,
Jinsong--
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