Re: kvm-unit-test failures

[Chris J Arges <chris.j.arges@canonical.com>]

On 08/29/2014 12:36 PM, Chris J Arges wrote:
> On 08/27/2014 05:05 PM, Paolo Bonzini wrote:
>>
>>
>> ----- Messaggio originale -----
>>> Da: "Chris J Arges" <chris.j.arges@canonical.com>
>>> A: "Paolo Bonzini" <pbonzini@redhat.com>, kvm@vger.kernel.org
>>> Inviato: Mercoledì, 27 agosto 2014 23:24:14
>>> Oggetto: kvm-unit-test failures (was: [PATCH 1/2 v3] add check parameter to run_tests configuration)
>>>
>>> <snip>
>>>> Thanks, looks good.  Are there more failures?
>>>>
>>>> Paolo
>>>>
>>>
>>> Paolo,
>>> Thanks for applying those patches!
>>>
>>> I now only see the two failures on my machine:
>>> model name      : Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz
>>>
>>> I'm running with the tip of kvm master:
>>> 0ac625df43ce9d085d4ff54c1f739611f4308b13 (Merge tag 'kvm-s390-20140825')
>>>
>>> sudo ./x86-run x86/apic.flat -smp 2 -cpu qemu64,+x2apic,+tsc-deadline |
>>> grep -v PASS
>>> qemu-system-x86_64 -enable-kvm -device pc-testdev -device
>>> isa-debug-exit,iobase=0xf4,iosize=0x4 -display none -serial stdio
>>> -device pci-testdev -kernel x86/apic.flat -smp 2 -cpu
>>> qemu64,+x2apic,+tsc-deadline
>>> enabling apic
>>> enabling apic
>>> paging enabled
>>> cr0 = 80010011
>>> cr3 = 7fff000
>>> cr4 = 20
>>> apic version: 1050014
>>> x2apic enabled
>>> FAIL: tsc deadline timer clearing
>>> tsc deadline timer enabled
>>
>> This is fixed in kvm/next (3.18).
>>
>>> SUMMARY: 16 tests, 1 unexpected failures
>>> Return value from qemu: 3
>>>
>>> sudo ./x86-run x86/kvmclock_test.flat -smp 2 --append "10000000 `date +%s`"
>>> qemu-system-x86_64 -enable-kvm -device pc-testdev -device
>>> isa-debug-exit,iobase=0xf4,iosize=0x4 -display none -serial stdio
>>> -device pci-testdev -kernel x86/kvmclock_test.flat -smp 2 --append
>>> 10000000 1409174399
>>> enabling apic
>>> enabling apic
>>> kvm-clock: cpu 0, msr 0x:44d4c0
>>> kvm-clock: cpu 0, msr 0x:44d4c0
>>> Wallclock test, threshold 5
>>> Seconds get from host:     1409174399
>>> Seconds get from kvmclock: 1409173176
>>> Offset:                    -1223
>>
>> Weird, your clock is 20 minutes behind in the VM than it
>> is in the host.  Is the offset always around -1200?  What
>> happens if you reboot?
>>
>> (I get 0, 1 or sometimes 2).
>>
>> Paolo
>>
> 
> Hi Paolo,
> 
> Results building with kvm queue tree
> (fd2752352bbc98850d83b5448a288d8991590317):
> CPU:
> model name      : Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz
> 
> I still get failures with the following test, I actually tested on
> multiple machines with identical hardware and the same failure occurred.
> In v3.13/v3.16 series kernels this passes. I'll look into which commit
> changed this result for me. I suspect it was fairly recent.
> 

I did a quick grep through the patches between v3.16 and the latest and
I found: (0d3da0d26e3c3515997c99451ce3b0ad1a69a36c KVM: x86: fix TSC
matching).

I reverted this patch and the test case passed for me. Looking at the
patch, I added an extra else statement as so:

	if (!matched) {
		kvm->arch.nr_vcpus_matched_tsc = 0;
	} else if (!already_matched) {
		kvm->arch.nr_vcpus_matched_tsc++;
	} else {
		printk("kvm: do we get here?\n");
	}

And indeed there is a condition where matched && already_matched are
both true. In this case we don't zero or increment nr_vcpus_matched_tsc.
Incrementing nr_vcpus_matched_tsc in that last else clause allows the
test to pass; however this is identical to the  logic before the patch.

Any suggestions for fixing this case?

Thanks,
--chris j arges

> ./x86-run x86/kvmclock_test.flat -smp 2 --append "10000000 `date +%s`" |
> grep -v PASS
> qemu-system-x86_64 -enable-kvm -device pc-testdev -device
> isa-debug-exit,iobase=0xf4,iosize=0x4 -display none -serial stdio
> -device pci-testdev -kernel x86/kvmclock_test.flat -smp 2 --append
> 10000000 1409160326
> enabling apic
> enabling apic
> kvm-clock: cpu 0, msr 0x:44d520
> kvm-clock: cpu 0, msr 0x:44d520
> Wallclock test, threshold 5
> Seconds get from host:     1409160326
> Seconds get from kvmclock: 1409153484
> Offset:                    -6842
> offset too large!
> Check the stability of raw cycle ...
> Worst warp -6841795339348
> Total vcpus: 2
> Test  loops: 10000000
> Total warps:  1
> Total stalls: 0
> Worst warp:   -6841795339348
> Raw cycle is not stable
> Monotonic cycle test:
> Worst warp -6836691572679
> Total vcpus: 2
> Test  loops: 10000000
> Total warps:  1
> Total stalls: 0
> Worst warp:   -6836691572679
> Measure the performance of raw cycle ...
> Total vcpus: 2
> Test  loops: 10000000
> TSC cycles:  1098400654
> Measure the performance of adjusted cycle ...
> Total vcpus: 2
> Test  loops: 10000000
> TSC cycles:  1106302952
> Return value from qemu: 3
> 
> This is another test that fails or hangs, this passes in 3.13, but fails
> on 3.16 with my testing. I'll dig into this more perhaps to find out
> which commit changes things.
> 
> ./x86-run x86/vmx.flat -smp 1 -cpu host,+vmx | grep -v PASS
> qemu-system-x86_64 -enable-kvm -device pc-testdev -device
> isa-debug-exit,iobase=0xf4,iosize=0x4 -display none -serial stdio
> -device pci-testdev -kernel x86/vmx.flat -smp 1 -cpu host,+vmx
> enabling apic
> paging enabled
> cr0 = 80010011
> cr3 = 7fff000
> cr4 = 20
> 
> Test suite: VMX capability reporting
> 
> Test suite: vmenter
> 
> Test suite: preemption timer
> 
> Test suite: control field PAT
> 
> Test suite: control field EFER
> 
> Test suite: CR shadowing
> 
> Test suite: I/O bitmap
> 
> Test suite: instruction intercept
> 
> Test suite: EPT framework
> FAIL: EPT violation - paging structure
> 
> Test suite: interrupt
> `ASS: running a guest with interrupt acknowledgement set
> 
> Test suite: debug controls
> 
> SUMMARY: 109 tests, 1 unexpected failures
> Return value from qemu: 3
> 
> Here is the test case hanging:
> 
> ./x86-run x86/vmx.flat -smp 1 -cpu host,+vmx | grep -v PASS
> qemu-system-x86_64 -enable-kvm -device pc-testdev -device
> isa-debug-exit,iobase=0xf4,iosize=0x4 -display none -serial stdio
> -device pci-testdev -kernel x86/vmx.flat -smp 1 -cpu host,+vmx
> enabling apic
> paging enabled
> cr0 = 80010011
> cr3 = 7fff000
> cr4 = 20
> 
> Test suite: VMX capability reporting
> 
> Test suite: vmenter
> 
> Test suite: preemption timer
> 
> Test suite: control field PAT
> 
> Test suite: control field EFER
> 
> Test suite: CR shadowing
> 
> Test suite: I/O bitmap
> 
> Test suite: instruction intercept
> 
> Test suite: EPT framework
> FAIL: EPT violation - paging structure
> FAIL: EPT - MMIO access
> 
> Test suite: interrupt
> FAIL: intercepted interrupt + hlt
> 
> Thanks,
> --chris j arges
>