From: Julien Grall <julien.grall@arm.com>
To: Stefano Stabellini <sstabellini@kernel.org>
Cc: Kaly.Xin@arm.com, nd@arm.com, steve.capper@arm.com,
Wei Chen <Wei.Chen@arm.com>,
xen-devel@lists.xen.org
Subject: Re: [PATCH v2 02/19] xen/arm: Remove vwfi while setting HCR_EL2 in init_traps
Date: Fri, 31 Mar 2017 09:34:10 +0100 [thread overview]
Message-ID: <c8ba87c2-54a0-cf99-e72c-7cc7bfb5b4c4@arm.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1703301458540.2723@sstabellini-ThinkPad-X260>
Hi Stefano,
On 03/30/2017 11:29 PM, Stefano Stabellini wrote:
>> I tried on different boards, and it gets stuck when initializing stage-2 page
>> table configuration on each CPU (see setup_virt_paging). The secondary CPUs
>> don't receive the SGI.
>>
>> Reading a bit more the ARM ARM (D7.2.33 in ARM DDI 0487A.k_iss10775), HCR_EL2
>> is unknown at reset. Whilst I already knew that, I would have expected to have
>> no impact on EL2 (at least in the non-VHE case). However, the value of the
>> {A,I,F}MO bits will affect the routing of physical IRQs to Xen.
>>
>> I have only gone quickly through the spec, so it might be possible to have
>> other necessary bits. It might be good to keep initialization here until
>> someone sit in front of the spec for few hours and check everything.
>>
>> So in this case I would prefer to keep the helper avoiding to have declared
>> twice the same flags. Stefano any opinions?
>
> I don't particularly care whether we keep the helper or not. From what
> you say we need to set HCR_EL2 in init_traps, but given that's only
> temporary, we don't necessarily need to write the same set of flags: for
> example HCR_TWI|HCR_TWE are useless at this stage. A minimal set would
> suffice. Either way, it's fine by me.
If we don't write the same set of flags, we need some documentation in
the code to explain why those flags are set for initialization (I
suspect a lot of them are not necessary) and that HCR flags whilst a
domain is running are set somewhere else.
Otherwise this is a call to miss setting some HCR flags in the right place.
That's why I suggested a helper (or a global variable), a single place
to get the default HCR flags rather than spreading.
Cheers,
--
Julien Grall
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next prev parent reply other threads:[~2017-03-31 8:34 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-30 9:13 [PATCH v2 00/19] Provide a command line option to choose how to handle SErrors Wei Chen
2017-03-30 9:13 ` [PATCH v2 01/19] xen/arm: Save ESR_EL2 to avoid using mismatched value in syndrome check Wei Chen
2017-03-30 13:31 ` Julien Grall
2017-03-31 3:26 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 02/19] xen/arm: Remove vwfi while setting HCR_EL2 in init_traps Wei Chen
2017-03-30 17:05 ` Julien Grall
2017-03-30 22:29 ` Stefano Stabellini
2017-03-31 5:58 ` Wei Chen
2017-03-31 8:34 ` Julien Grall [this message]
2017-03-30 9:13 ` [PATCH v2 03/19] xen/arm: Move parse_vwfi from trap.c to domain.c Wei Chen
2017-03-30 9:13 ` [PATCH v2 04/19] xen/arm: Restore HCR_EL2 register Wei Chen
2017-03-30 17:07 ` Julien Grall
2017-03-30 22:03 ` Stefano Stabellini
2017-03-31 2:10 ` Wei Chen
2017-03-31 8:39 ` Julien Grall
2017-03-31 8:59 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 05/19] xen/arm: Avoid setting/clearing HCR_RW at every context switch Wei Chen
2017-03-30 17:12 ` Julien Grall
2017-03-30 21:21 ` Stefano Stabellini
2017-03-30 9:13 ` [PATCH v2 06/19] xen/arm: Save HCR_EL2 when a guest took the SError Wei Chen
2017-03-30 9:13 ` [PATCH v2 07/19] xen/arm: Introduce a virtual abort injection helper Wei Chen
2017-03-30 17:20 ` Julien Grall
2017-03-30 21:24 ` Stefano Stabellini
2017-03-31 5:25 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 08/19] xen/arm: Introduce a command line parameter for SErrors/Aborts Wei Chen
2017-03-30 17:39 ` Julien Grall
2017-03-31 5:28 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 09/19] xen/arm: Introduce a initcall to update cpu_hwcaps by serror_op Wei Chen
2017-03-30 17:51 ` Julien Grall
2017-03-30 18:02 ` Julien Grall
2017-03-30 21:28 ` Stefano Stabellini
2017-03-31 8:50 ` Julien Grall
2017-03-30 9:13 ` [PATCH v2 10/19] xen/arm64: Use alternative to skip the check of pending serrors Wei Chen
2017-03-30 9:13 ` [PATCH v2 11/19] xen/arm32: " Wei Chen
2017-03-30 18:06 ` Julien Grall
2017-03-30 21:29 ` Stefano Stabellini
2017-03-31 5:33 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 12/19] xen/arm: Move macro VABORT_GEN_BY_GUEST to common header Wei Chen
2017-03-30 21:36 ` Stefano Stabellini
2017-03-31 5:35 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 13/19] xen/arm: Introduce new helpers to handle guest/hyp SErrors Wei Chen
2017-03-30 9:13 ` [PATCH v2 14/19] xen/arm: Replace do_trap_guest_serror with new helpers Wei Chen
2017-03-30 9:13 ` [PATCH v2 15/19] xen/arm: Unmask the Abort/SError bit in the exception entries Wei Chen
2017-03-30 9:13 ` [PATCH v2 16/19] xen/arm: Introduce a helper to synchronize SError Wei Chen
2017-03-30 18:28 ` Julien Grall
2017-03-30 18:32 ` Julien Grall
2017-03-30 18:37 ` Julien Grall
2017-03-31 5:51 ` Wei Chen
2017-03-31 10:55 ` Wei Chen
2017-03-31 11:06 ` Julien Grall
2017-03-31 11:09 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 17/19] xen/arm: Isolate the SError between the context switch of 2 vCPUs Wei Chen
2017-03-30 21:49 ` Stefano Stabellini
2017-03-30 22:00 ` Julien Grall
2017-03-31 5:52 ` Wei Chen
2017-03-30 9:13 ` [PATCH v2 18/19] xen/arm: Prevent slipping hypervisor SError to guest Wei Chen
2017-03-30 9:13 ` [PATCH v2 19/19] xen/arm: Handle guest external abort as guest SError Wei Chen
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