Messages in this thread | | | Subject | Re: Ping: [PATCH v15 00/13] support "task_isolation" mode | From | Francis Giraldeau <> | Date | Wed, 7 Sep 2016 17:39:26 -0400 |
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On 2016-09-07 05:11 PM, Francis Giraldeau wrote: > The syscall test fails on x86: > $ sudo ./isolation > [...] > test_syscall: FAIL (0x100) > test_syscall (SIGUSR1): FAIL (0x100) > > I wanted to debug this problem with gdb and a KVM virtual machine. However, the TSC clock source is detected as non reliable, even with the boot parameter tsc=reliable, and therefore prctl(PR_SET_TASK_ISOLATION, PR_TASK_ISOLATION_ENABLE) always returns EAGAIN. Is there a trick to run task isolation in a VM (at least for debugging purposes)?
OK, got it. The guest kernel must be compiled with CONFIG_KVM_GUEST, and then with virsh edit, set the clock configuration of the VM (under <domain>):
<clock offset='utc'> <timer name='kvmclock'/> </clock>
Of course, the jitter is horrible, but at least it is possible to debug with GDB.
Cheers,
Francis
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