From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Steve Capper <Steve.Capper@arm.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Catalin Marinas <Catalin.Marinas@arm.com>,
Will Deacon <Will.Deacon@arm.com>,
"jcm@redhat.com" <jcm@redhat.com>,
"ard.biesheuvel@linaro.org" <ard.biesheuvel@linaro.org>,
nd <nd@arm.com>
Subject: Re: [PATCH V4 5/6] arm64: mm: introduce 52-bit userspace support
Date: Thu, 6 Dec 2018 14:35:20 +0000 [thread overview]
Message-ID: <c87c833a-7dfc-6cd4-aad7-119df9bd7178@arm.com> (raw)
In-Reply-To: <20181206122603.GB17473@capper-debian.cambridge.arm.com>
On 06/12/2018 12:26, Steve Capper wrote:
> On Wed, Dec 05, 2018 at 06:22:27PM +0000, Suzuki K Poulose wrote:
>> Hi Steve,
>>
> [...]
>> I think we may need a check for the secondary CPUs to make sure that they have
>> the 52bit support once the boot CPU has decided to use the feature and fail the
>> CPU bring up (just like we do for the granule support).
>>
>> Suzuki
>
> Hi Suzuki,
> I have just written a patch to detect a mismatch between 52-bit VA that
> is being tested now.
>
> As 52-bit kernel VA support is coming in future, the patch checks for a
> mismatch during the secondary boot path and, if one is found, prevents
> the secondary from booting (and displays an error message to the user).
Right now, it is the boot CPU which decides the Userspace 52bit VA, isn't it ?
Irrespective of the kernel VA support, the userspace must be able to run on
all the CPUs on the system, right ? So don't we need it now, with this series ?
Cheers
Suzuki
next prev parent reply other threads:[~2018-12-06 14:35 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-05 16:41 [PATCH V4 0/6] 52-bit userspace VAs Steve Capper
2018-12-05 16:41 ` [PATCH V4 1/6] mm: mmap: Allow for "high" userspace addresses Steve Capper
2018-12-05 16:41 ` [PATCH V4 2/6] arm64: mm: Introduce DEFAULT_MAP_WINDOW Steve Capper
2018-12-05 17:36 ` Catalin Marinas
2018-12-06 12:24 ` Steve Capper
2018-12-05 16:41 ` [PATCH V4 3/6] arm64: mm: Define arch_get_mmap_end, arch_get_mmap_base Steve Capper
2018-12-05 16:41 ` [PATCH V4 4/6] arm64: mm: Offset TTBR1 to allow 52-bit PTRS_PER_PGD Steve Capper
2018-12-06 11:50 ` Catalin Marinas
2018-12-06 12:27 ` Steve Capper
2018-12-05 16:41 ` [PATCH V4 5/6] arm64: mm: introduce 52-bit userspace support Steve Capper
2018-12-05 18:22 ` Suzuki K Poulose
2018-12-06 12:26 ` Steve Capper
2018-12-06 14:35 ` Suzuki K Poulose [this message]
2018-12-06 14:52 ` Steve Capper
2018-12-05 16:41 ` [PATCH V4 6/6] arm64: mm: Allow forcing all userspace addresses to 52-bit Steve Capper
2018-12-06 11:51 ` Catalin Marinas
2018-12-06 12:28 ` Steve Capper
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