From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: KVM: iterate over all CPUs for CPU compatibility check
Date: Mon, 22 Apr 2013 12:02:59 +0100 [thread overview]
Message-ID: <517518E3.5020209@arm.com> (raw)
In-Reply-To: <517512CA.6070503@linaro.org>
On 22/04/13 11:36, Andre Przywara wrote:
> On 04/19/2013 06:13 PM, Christoffer Dall wrote:
>> On Fri, Apr 19, 2013 at 5:58 AM, Andre Przywara
>> <andre.przywara@linaro•org> wrote:
>>> On 04/17/2013 11:12 AM, Christoffer Dall wrote:
>>>>
>>>> ...
>>>>
>>>> You could also try installing a vector handler early and detect faults,
>>>> and add an alternative return path from the init function with some
>>>> error reporting value in r0 or something like that, just for debugging,
>>>> naturally, but that could be a way to detect if we really are taking
>>>> recursive faults here.
>>>
>>>
>>> OK, I added code to return earlier on CPUs not from cluster 0.
>>> Indeed it hangs in the HSCR write. The two A15s pass this instruction,
>>> writing 0x30c5187F into the register.
>>> This means all the fixed bits for A15 correctly, C,A,M and I set and WXN,
>>> EE, TE cleared. FI was also cleared
>>> The A7 wanted to write the very same value. I tried to set bit 21, which
>>> kind of the A7 TRM hints to do: but no change.
>>> Before the HSCLTR write, the register reads 0x30c50878, with SCTLR being
>>> 0x30c5387d.
>>> So the code wants to set M, A, C and I in HSCLTR. Interestingly SCTLR has
>>> the V bits set, could that be an issue?
>>>
>> Can you try writing 0x30c50879 into the register instead? Basically
>> check to see if enabling caches or alignment checks causes the issue,
>> or if it is indeed enabling the MMU that's the issue... If that works,
>> start a bisect on the remaining bits. Also, just for fun, could you
>> try flushing the entire I-cache before writing into the HSCLTR?
>
> OK, both clearing the I-bit and doing an "isb; ICIALLU" before the "isb;
> write HSCLTR; isb" worked, the kernel boots on and KVM is enabled.
>
> I could easily make a patch, but I am not sure how to proceed from here:
>
> 1.) At least I don't have an understanding why this is only a problem on
> A7 and not on A15. I would feel better if we have an explanation for
> this. Mark, Will, Peter: any ideas?
Blink!
Can you check your board.txt config file? It should have a line that
starts with "SCC: 0x400 ..."
If not, can you add a line that reads:
SCC: 0x400 0x00000000
Thanks,
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2013-04-22 11:02 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-12 13:04 [PATCH] ARM: KVM: iterate over all CPUs for CPU compatibility check Andre Przywara
2013-04-12 13:24 ` Marc Zyngier
2013-04-12 13:40 ` Peter Maydell
2013-04-12 13:49 ` Marc Zyngier
2013-04-17 10:19 ` Russell King - ARM Linux
2013-04-17 10:35 ` Marc Zyngier
2013-04-17 11:07 ` Christoffer Dall
2013-04-17 11:30 ` Marc Zyngier
2013-04-17 11:38 ` Peter Maydell
2013-04-17 11:42 ` Alexander Graf
2013-04-17 11:45 ` Christoffer Dall
2013-04-17 12:24 ` Marc Zyngier
2013-04-17 12:25 ` Peter Maydell
2013-04-17 12:28 ` Marc Zyngier
2013-04-17 12:38 ` Peter Maydell
2013-04-17 13:00 ` Marc Zyngier
2013-04-17 19:28 ` Christoffer Dall
2013-04-17 11:38 ` Christoffer Dall
2013-04-12 13:58 ` Andre Przywara
2013-04-12 14:14 ` Marc Zyngier
2013-04-15 4:57 ` Christoffer Dall
2013-04-15 7:50 ` Marc Zyngier
2013-04-15 8:28 ` Christoffer Dall
2013-04-15 8:43 ` Marc Zyngier
2013-04-15 8:54 ` Christoffer Dall
2013-04-15 9:14 ` Peter Maydell
2013-04-15 9:39 ` Andre Przywara
2013-04-15 9:45 ` Peter Maydell
[not found] ` <CAJRNFKJoBzgt4UhxsH65_LyhcGXPnzB_pg3q-zeYT2OVv59q4A@mail.gmail.com>
2013-04-15 13:13 ` Andre Przywara
2013-04-15 13:48 ` Will Deacon
2013-04-15 14:26 ` Andre Przywara
2013-04-15 14:39 ` Peter Maydell
2013-04-15 14:53 ` Alexander Spyridakis
2013-04-16 16:26 ` Christoffer Dall
2013-04-16 16:33 ` Marc Zyngier
2013-04-17 8:08 ` Andre Przywara
2013-04-17 8:16 ` Marc Zyngier
[not found] ` <CAEDV+g+3nkdvbLdj0m-ZdDKt0JY2vgzhP2AQA2nf=R3h4yTQmQ@mail.gmail.com>
2013-04-19 12:58 ` Andre Przywara
2013-04-19 16:13 ` Christoffer Dall
2013-04-22 10:36 ` Andre Przywara
2013-04-22 11:02 ` Marc Zyngier [this message]
2013-04-22 11:14 ` Marc Zyngier
2013-04-22 14:35 ` Andre Przywara
2013-04-16 15:59 ` Christoffer Dall
2013-04-16 16:03 ` Christoffer Dall
2013-04-16 18:37 ` Alexander Spyridakis
2013-04-16 18:43 ` Alexander Spyridakis
2013-04-16 23:13 ` Christoffer Dall
2013-04-16 0:26 ` Geoff Levand
2013-04-16 16:24 ` Christoffer Dall
2013-04-16 16:40 ` Marc Zyngier
2013-04-17 8:01 ` Andre Przywara
-- strict thread matches above, loose matches on Subject: below --
2013-04-17 10:52 Andre Przywara
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