From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 6/6] ARM: kvm: TMP: Commit the hyp page tables to main memory
Date: Thu, 14 Nov 2013 20:19:13 -0500 [thread overview]
Message-ID: <52857691.8000907@ti.com> (raw)
In-Reply-To: <20131115004250.GH20516@lvm>
On Thursday 14 November 2013 07:42 PM, Christoffer Dall wrote:
> On Thu, Nov 14, 2013 at 07:36:37PM -0500, Santosh Shilimkar wrote:
>> On Thursday 14 November 2013 07:27 PM, Christoffer Dall wrote:
>>> On Thu, Nov 14, 2013 at 07:15:44PM -0500, Santosh Shilimkar wrote:
>>>> On Thursday 14 November 2013 07:11 PM, Christoffer Dall wrote:
>>>>> On Thu, Nov 14, 2013 at 02:37:46PM -0500, Santosh Shilimkar wrote:
>>>>>> This is a temporary hack which I have to use to avoid a weired crash while
>>>>>> starting the guest OS on Keystsone. They are random crashesh while the
>>>>>> guest os userspace starts. Additional data point is, it seen only with first
>>>>>> guest OS lanch. Subsequest guest OS starts normal.
>>>>>>
>>>>>
>>>>> what crashes? The guest? Where, how?
>>>>>
>>>> When guest userspace starts. The crashes are random but always after the
>>>> guest init process have started.
>>>>
>>>
>>> So you get a guest kernel crash when guest userspace starts?
>>>
>>> Are the crashes completely random or is it always some pointer
>>> dereference that goes wrong, is it init crashing and causing the kernel
>>> to crash (from killed init), or is it always the same kernel thread, or
>>> anything coherent at all?
>>>
>> Completely random. I have seen almost all of the above possible crashes
>> like pointer derefence, init process skipping some steps, console going
>> for toss, the log in prompt just won't let me log in etc
>>
>>
>>> It could be anything, really. You could try a really brute force
>>> debugging option of adding a complete cache flush at the end of
>>> user_mem_abort in arch/arm/kvm/mmu.c to see if this is cache related at
>>> all...
>>>
>> I will try that. I strongly suspect this has to do with bad page tables.
>> remember I see this issue with when using memory which starts beyond 4GB.
>>
full cache full at end of user_mem_abort() doesn't help. So it might not be
cache related then.
>
> But once it crashes, if you kill the VM process and start a new one,
> then the new one runs flawlessly? Did you stress test the second VM
> (hackbench or something) so we're sure the second one is indeed stable?
>
> What happens if you start a guest, kill it immediately, and then start
> another guest?
>
And the observation about subsequent VM's being stable also doesn't hold
true. Additional symptom what I saw was segmentation fault as well as
hitting kvm load/store trap. This also possibly indicates instructions
corruption.
Regards,
Santosh
next prev parent reply other threads:[~2013-11-15 1:19 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-14 19:37 [PATCH 0/6] ARM/AMR64: Few patches on kvm and mm code Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 1/6] arm64: mm: Add __virt_to_idmap() to keep kvm build happy Santosh Shilimkar
2013-11-15 13:34 ` Catalin Marinas
2013-11-15 14:55 ` Santosh Shilimkar
2013-11-15 14:58 ` Catalin Marinas
2013-11-15 15:31 ` Santosh Shilimkar
2013-11-15 15:05 ` Marc Zyngier
2013-11-15 15:25 ` Santosh Shilimkar
2013-11-15 15:29 ` Marc Zyngier
2013-11-15 15:31 ` Catalin Marinas
2013-11-15 15:33 ` Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 2/6] ARM: kvm: Use virt_to_idmap instead of virt_to_phys for idmap mappings Santosh Shilimkar
2013-11-15 0:12 ` Christoffer Dall
2013-11-14 19:37 ` [PATCH 3/6] ARM: mm: Drop the lowmem watermark check from virt_addr_valid() Santosh Shilimkar
2013-11-15 0:22 ` Christoffer Dall
2013-11-15 0:31 ` Santosh Shilimkar
2013-11-15 0:40 ` Christoffer Dall
2013-11-15 11:48 ` Marc Zyngier
2013-11-15 11:43 ` Marc Zyngier
2013-11-15 14:55 ` Santosh Shilimkar
2013-11-15 15:08 ` Marc Zyngier
2013-11-15 15:46 ` Christoffer Dall
2013-11-15 14:20 ` Russell King - ARM Linux
2013-11-15 15:40 ` Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 4/6] arm64: " Santosh Shilimkar
2013-11-15 13:39 ` Catalin Marinas
2013-11-15 14:25 ` Marc Zyngier
2013-11-15 14:57 ` Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 5/6] ARM: kvm: Use phys_addr_t instead of unsigned long in mm code Santosh Shilimkar
2013-11-15 0:09 ` Christoffer Dall
2013-11-15 0:10 ` Santosh Shilimkar
2013-11-15 11:58 ` Marc Zyngier
2013-11-14 19:37 ` [PATCH 6/6] ARM: kvm: TMP: Commit the hyp page tables to main memory Santosh Shilimkar
2013-11-14 22:36 ` Santosh Shilimkar
2013-11-15 0:11 ` Christoffer Dall
2013-11-15 0:15 ` Santosh Shilimkar
2013-11-15 0:27 ` Christoffer Dall
2013-11-15 0:36 ` Santosh Shilimkar
2013-11-15 0:42 ` Christoffer Dall
2013-11-15 1:19 ` Santosh Shilimkar [this message]
2013-11-15 1:35 ` Christoffer Dall
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