From: Julien Grall <julien.grall@arm.com>
To: Shannon Zhao <zhaoshenglong@huawei.com>, xen-devel@lists.xen.org
Cc: sstabellini@kernel.org, wei.liu2@citrix.com,
Steve Capper <Steve.Capper@arm.com>,
ian.jackson@eu.citrix.com, peter.huangpeng@huawei.com,
shannon.zhao@linaro.org
Subject: Re: [PATCH RESEND 03/14] libxc: Add placeholders for ACPI tables blob and size
Date: Tue, 7 Jun 2016 13:02:27 +0100 [thread overview]
Message-ID: <5756B7D3.5020904@arm.com> (raw)
In-Reply-To: <5756B33D.7000708@arm.com>
Hello Shannon,
On 07/06/16 12:42, Julien Grall wrote:
>>>>> Is there any particular reason to expose the list of the tables
>>>>> outside
>>>>> of the building code?
>>>>>
>>>>> I would provide a single buffer with all the tables inside. Similar to
>>>>> what you did for building the tables in the hypervisor.
>>>> When it loads these tables to guest memory space, it needs to update
>>>> the
>>>> entries (pointing to other tables) of XSDT and also the
>>>> xsdt_physical_address in RSDP.
>>>
>>> Why can't we load the ACPI tables at an hardcoded place in the memory
>>> (for instance always at the beginning of the RAM)?
>>>
>> I think it's more reasonable to let the codes dynamically compute where
>> it should put these tables at like what it does for the devicetree blob.
>>
>> And to an hardcoded place, can you make sure that kind of place is
>> always available and not used by others?
>
> Yes, the toolstack is in charge of the memory layout. So it can ensure
> that no-one else is using this region.
>
> My concern is, based on you patch #13, the ACPI tables are allocated
> just after all the other modules. However, they cannot be relocated by
> the kernel because they contain physical address. So they have to stay
> in place for all the life of the domain.
>
> We should put them in a place where it will not impact the memory
> allocation of the guest. The start of the RAM is a good place for that.
I though a bit more on this suggestion. If the ACPI tables are put at
the beginning of the RAM, a guest may not be able to use super page.
I would suggest to move the ACPI table out of the real RAM to avoid any
potential issue with the kernel memory allocation.
For instance we could define a IPA range to be use for ACPI (e.g
0x20000000 - 0x20200000) and expose to the guest using the ACPI_NVS type
in the UEFI memory map.
Any opinion on this?
Regards,
--
Julien Grall
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next prev parent reply other threads:[~2016-06-07 12:02 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 5:02 [PATCH RESEND 00/14] Xen ARM DomU ACPI support Shannon Zhao
2016-05-31 5:02 ` [PATCH RESEND 01/14] libxl/arm: Fix the function name in error log Shannon Zhao
2016-06-03 19:25 ` Wei Liu
2016-06-17 10:46 ` Wei Liu
2016-06-20 1:12 ` Shannon Zhao
2016-05-31 5:02 ` [PATCH RESEND 02/14] libxl/arm: Factor out codes for generating DTB Shannon Zhao
2016-06-03 19:25 ` Wei Liu
2016-05-31 5:02 ` [PATCH RESEND 03/14] libxc: Add placeholders for ACPI tables blob and size Shannon Zhao
2016-06-06 10:00 ` Stefano Stabellini
2016-06-06 12:16 ` Wei Liu
2016-06-06 14:20 ` Shannon Zhao
2016-06-07 11:05 ` Julien Grall
2016-06-07 11:13 ` Shannon Zhao
2016-06-07 11:27 ` Julien Grall
2016-06-07 11:35 ` Shannon Zhao
2016-06-07 11:42 ` Julien Grall
2016-06-07 11:59 ` Shannon Zhao
2016-06-07 12:06 ` Julien Grall
2016-06-07 12:32 ` Shannon Zhao
2016-06-07 13:06 ` Julien Grall
2016-06-16 6:53 ` Shannon Zhao
2016-06-16 10:21 ` Julien Grall
2016-06-16 10:45 ` Shannon Zhao
2016-06-16 11:04 ` Julien Grall
2016-06-16 10:49 ` Wei Liu
2016-06-16 10:53 ` Shannon Zhao
2016-06-16 11:04 ` Wei Liu
2016-06-07 12:02 ` Julien Grall [this message]
2016-06-07 12:27 ` Shannon Zhao
2016-05-31 5:02 ` [PATCH RESEND 04/14] tools: add ACPI tables relevant definitions Shannon Zhao
2016-06-06 10:04 ` Stefano Stabellini
2016-06-06 10:11 ` Julien Grall
2016-06-06 10:27 ` Shannon Zhao
2016-06-06 12:16 ` Wei Liu
2016-06-06 14:19 ` Shannon Zhao
2016-06-22 3:24 ` Shannon Zhao
2016-06-22 8:35 ` Julien Grall
2016-06-22 8:50 ` Shannon Zhao
2016-06-22 8:55 ` Julien Grall
2016-06-22 9:38 ` [PATCH RESEND 04/14] tools: add ACPI tables relevant definitions (and more) Wei Liu
2016-06-22 10:06 ` Shannon Zhao
2016-05-31 5:02 ` [PATCH RESEND 05/14] libxl/arm: Construct ACPI GTDT table Shannon Zhao
2016-06-06 11:40 ` Stefano Stabellini
2016-06-06 11:52 ` Julien Grall
2016-06-06 12:04 ` Stefano Stabellini
2016-06-06 14:31 ` Shannon Zhao
2016-06-06 14:50 ` Stefano Stabellini
2016-06-06 15:42 ` Julien Grall
2016-06-07 9:41 ` Stefano Stabellini
2016-06-06 15:35 ` Julien Grall
2016-06-07 9:48 ` Stefano Stabellini
2016-06-07 11:55 ` Wei Liu
2016-06-17 3:29 ` Shannon Zhao
2016-06-17 8:17 ` Julien Grall
2016-06-17 9:15 ` Stefano Stabellini
2016-06-17 13:27 ` Julien Grall
2016-06-06 12:18 ` Wei Liu
2016-06-07 11:02 ` Julien Grall
2016-06-07 11:19 ` Julien Grall
2016-06-07 11:30 ` Shannon Zhao
2016-06-07 11:36 ` Julien Grall
2016-06-07 11:39 ` Shannon Zhao
2016-06-07 11:43 ` Julien Grall
2016-05-31 5:02 ` [PATCH RESEND 06/14] libxl/arm: Construct ACPI FADT table Shannon Zhao
2016-06-07 13:17 ` Julien Grall
2016-06-07 14:13 ` Shannon Zhao
2016-06-07 14:14 ` Julien Grall
2016-05-31 5:02 ` [PATCH RESEND 07/14] libxl/arm: Construct ACPI DSDT table Shannon Zhao
2016-06-07 13:42 ` Julien Grall
2016-06-16 6:25 ` Shannon Zhao
2016-06-16 9:44 ` Julien Grall
2016-06-16 10:01 ` Stefano Stabellini
2016-05-31 5:03 ` [PATCH RESEND 08/14] libxl/arm: Construct ACPI MADT table Shannon Zhao
2016-06-07 13:40 ` Julien Grall
2016-05-31 5:03 ` [PATCH RESEND 09/14] libxl/arm: Construct ACPI XSDT table Shannon Zhao
2016-05-31 5:03 ` [PATCH RESEND 10/14] libxl/arm: Construct ACPI RSDP table Shannon Zhao
2016-05-31 5:03 ` [PATCH RESEND 11/14] libxl/arm: Initialize domain param HVM_PARAM_CALLBACK_IRQ Shannon Zhao
2016-05-31 5:03 ` [PATCH RESEND 12/14] libxl/arm: Add ACPI module Shannon Zhao
2016-06-07 13:47 ` Julien Grall
2016-05-31 5:03 ` [PATCH RESEND 13/14] libxl/arm: initialize memory information of ACPI blob Shannon Zhao
2016-06-06 11:40 ` Stefano Stabellini
2016-06-06 14:35 ` Shannon Zhao
2016-05-31 5:03 ` [PATCH RESEND 14/14] libxc/xc_dom_core: Copy ACPI tables to guest memory space Shannon Zhao
2016-05-31 10:47 ` [PATCH RESEND 00/14] Xen ARM DomU ACPI support Julien Grall
2016-05-31 14:19 ` Shannon Zhao
2016-06-03 19:24 ` Wei Liu
2016-06-03 20:02 ` Konrad Rzeszutek Wilk
2016-06-03 20:20 ` Boris Ostrovsky
2016-06-03 20:27 ` Wei Liu
2016-06-03 20:36 ` Boris Ostrovsky
2016-06-06 11:41 ` Stefano Stabellini
2016-06-06 12:26 ` Wei Liu
2016-06-06 15:37 ` Boris Ostrovsky
2016-06-06 16:50 ` Boris Ostrovsky
2016-06-07 10:54 ` Julien Grall
2016-06-07 14:24 ` Boris Ostrovsky
2016-06-06 15:48 ` Julien Grall
2016-06-07 1:07 ` Shannon Zhao
2016-06-07 11:00 ` Julien Grall
2016-06-16 11:20 ` Wei Liu
2016-06-16 13:25 ` Boris Ostrovsky
2016-06-17 10:14 ` Wei Liu
2016-06-17 2:03 ` Shannon Zhao
2016-06-17 8:18 ` Julien Grall
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