From: Julien Grall <julien.grall@citrix.com>
To: Ian Campbell <ian.campbell@citrix.com>,
Shannon Zhao <shannon.zhao@linaro.org>,
Shannon Zhao <zhaoshenglong@huawei.com>,
xen-devel <xen-devel@lists.xen.org>
Cc: Hangaohuai <hangaohuai@huawei.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
andrew@fubar.geek.nz,
"Huangpeng (Peter)" <peter.huangpeng@huawei.com>,
Stefano Stabellini <stefano.stabellini@citrix.com>,
David Vrabel <david.vrabel@citrix.com>,
Jan Beulich <jbeulich@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Parth Dixit <parth.dixit@linaro.org>,
Christoffer Dall <christoffer.dall@linaro.org>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: Design doc of adding ACPI support for arm64 on Xen - version 5
Date: Wed, 2 Sep 2015 14:48:01 +0100 [thread overview]
Message-ID: <55E6FE11.3060401@citrix.com> (raw)
In-Reply-To: <1441200364.26292.190.camel@citrix.com>
On 02/09/15 14:26, Ian Campbell wrote:
>>>> I think the problem is how you reserved this region in the EFI memory
>>>> table. From what I saw, you marked this new memory with EFI_MEMORY_WB
>>>> (which means that the region can be usable by Linux).
>>>>
>>> Yes, I mark it with EFI_MEMORY_WB. Is this right?
>>
>> I would say no, but it's only because I looked at the kernel code
>> quickly.
>>
>> You have to looks how ACPI region/UEFI tables are described in the host
>> EFI memory map and mimicking for the DOM0 EFI memory map.
>
> Surely it is the type (EfiACPIReclaimMemory, EfiACPIMemoryNVS etc) and not
> the mapping attributes which should control whether an OS considers a
> region usable? At least until the OS is done parsing tables neither of
> those are usable (which implies we want NVS as our type, unless the memory
> is intended to be reclaimed by dom0, implying it should own it).
It looks like that Linux on ARM64 is considering any region with
EFI_MEMORY_WB set as normal RAM and will try to add as System RAM (see
reserve_regions in arch/arm64/kernel/efi.c).
At the same time, having WB set for a region that should be read-only
looks like wrong to me.
Regards,
--
Julien Grall
next prev parent reply other threads:[~2015-09-02 13:48 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-28 9:45 Design doc of adding ACPI support for arm64 on Xen - version 5 Shannon Zhao
2015-08-28 12:55 ` Julien Grall
2015-08-29 1:00 ` Shannon Zhao
2015-08-31 7:33 ` Jan Beulich
2015-08-31 11:44 ` Julien Grall
2015-08-31 12:03 ` Shannon Zhao
2015-08-31 12:34 ` Julien Grall
2015-09-01 4:12 ` Shannon Zhao
2015-09-01 11:28 ` Julien Grall
2015-09-01 12:35 ` Shannon Zhao
2015-09-01 13:40 ` Julien Grall
2015-09-01 14:03 ` Jan Beulich
2015-09-01 14:20 ` Julien Grall
2015-09-02 6:02 ` Shannon Zhao
2015-09-02 8:41 ` Jan Beulich
2015-09-02 9:18 ` Christoffer Dall
2015-09-02 11:15 ` Julien Grall
2015-09-02 9:25 ` Shannon Zhao
2015-09-02 12:30 ` Jan Beulich
2015-09-02 11:09 ` Julien Grall
2015-09-02 12:02 ` Shannon Zhao
2015-09-02 12:52 ` Julien Grall
2015-09-02 13:26 ` Ian Campbell
2015-09-02 13:48 ` Julien Grall [this message]
2015-09-02 13:54 ` Ian Campbell
2015-09-02 13:57 ` Christoffer Dall
2015-09-02 15:27 ` Leif Lindholm
2015-09-02 15:37 ` Ard Biesheuvel
2015-09-02 14:00 ` Jan Beulich
2015-09-02 12:58 ` Ian Campbell
2015-08-28 15:06 ` Jan Beulich
2015-08-29 1:29 ` Shannon Zhao
2015-08-31 7:39 ` Jan Beulich
2015-08-31 8:51 ` Shannon Zhao
2015-08-31 9:40 ` Jan Beulich
2015-08-31 11:31 ` Shannon Zhao
2015-08-31 11:46 ` Jan Beulich
2015-09-02 12:54 ` Ian Campbell
2015-09-02 13:59 ` Shannon Zhao
2015-09-02 14:24 ` Ian Campbell
2015-09-02 12:18 ` Ian Campbell
2015-09-07 3:37 ` Shannon Zhao
2015-09-07 10:47 ` Stefano Stabellini
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55E6FE11.3060401@citrix.com \
--to=julien.grall@citrix.com \
--cc=andrew@fubar.geek.nz \
--cc=boris.ostrovsky@oracle.com \
--cc=christoffer.dall@linaro.org \
--cc=david.vrabel@citrix.com \
--cc=hangaohuai@huawei.com \
--cc=ian.campbell@citrix.com \
--cc=jbeulich@suse.com \
--cc=parth.dixit@linaro.org \
--cc=peter.huangpeng@huawei.com \
--cc=roger.pau@citrix.com \
--cc=shannon.zhao@linaro.org \
--cc=stefano.stabellini@citrix.com \
--cc=stefano.stabellini@eu.citrix.com \
--cc=xen-devel@lists.xen.org \
--cc=zhaoshenglong@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).