* [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm
@ 2022-04-27 13:22 Julien Grall
2022-04-27 13:34 ` Jan Beulich
2022-04-27 13:51 ` Bertrand Marquis
0 siblings, 2 replies; 5+ messages in thread
From: Julien Grall @ 2022-04-27 13:22 UTC (permalink / raw)
To: xen-devel
Cc: bertrand.marquis, Julien Grall, Andrew Cooper, George Dunlap,
Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu
From: Julien Grall <jgrall@amazon.com>
As part of XSA-385, SUPPORT.MD gained a statement regarding the amount
of physical memory supported.
However, booting Xen on a Arm platform with that amount of memory would
result to a breakage because the frametable area is too small.
The wiki [1] (as of April 2022) claims we were able to support up to
5 TiB on Arm64 and 16 GiB. However, this is not the case because
the struct page_info has always been bigger than expected (56 bytes
for 64-bit and 32-bytes for 32-bit).
I don't have any HW with such amount of memory. So rather than
modifying the code, take the opportunity to use the limit that should
work on Arm (2 TiB for 64-bit and 12 GiB for 32-bit).
Signed-off-by: Julien Grall <jgrall@amazon.com>
---
SUPPORT.md | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/SUPPORT.md b/SUPPORT.md
index 088dda9561c1..1e3c69a07615 100644
--- a/SUPPORT.md
+++ b/SUPPORT.md
@@ -50,9 +50,10 @@ For the Cortex A57 r0p0 - r1p1, see Errata 832075.
### Physical Memory
- Status: Supported up to 8 TiB
-
-Hosts with more memory are supported, but not security supported.
+ Status, x86: Supported up to 8 TiB. Hosts with more memory are
+ supported but not security support.
+ Status, Arm32: Supported up to 12 GiB
+ Status, Arm64: Supported up to 2 TiB
### Physical Memory Hotplug
--
2.32.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm
2022-04-27 13:22 [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm Julien Grall
@ 2022-04-27 13:34 ` Jan Beulich
2022-04-27 13:39 ` Julien Grall
2022-04-27 13:51 ` Bertrand Marquis
1 sibling, 1 reply; 5+ messages in thread
From: Jan Beulich @ 2022-04-27 13:34 UTC (permalink / raw)
To: Julien Grall
Cc: bertrand.marquis, Julien Grall, Andrew Cooper, George Dunlap,
Stefano Stabellini, Wei Liu, xen-devel
On 27.04.2022 15:22, Julien Grall wrote:
> --- a/SUPPORT.md
> +++ b/SUPPORT.md
> @@ -50,9 +50,10 @@ For the Cortex A57 r0p0 - r1p1, see Errata 832075.
>
> ### Physical Memory
>
> - Status: Supported up to 8 TiB
> -
> -Hosts with more memory are supported, but not security supported.
> + Status, x86: Supported up to 8 TiB. Hosts with more memory are
> + supported but not security support.
Nit: "supported" also in the 2nd instance, as it was before. I think
retaining the comma would also be beneficial.
> + Status, Arm32: Supported up to 12 GiB
> + Status, Arm64: Supported up to 2 TiB
This really will need to be ack-ed by an Arm person, so I don't see
value in me providing an ack.
Jan
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm
2022-04-27 13:34 ` Jan Beulich
@ 2022-04-27 13:39 ` Julien Grall
0 siblings, 0 replies; 5+ messages in thread
From: Julien Grall @ 2022-04-27 13:39 UTC (permalink / raw)
To: Jan Beulich
Cc: bertrand.marquis, Julien Grall, Andrew Cooper, George Dunlap,
Stefano Stabellini, Wei Liu, xen-devel
Hi Jan,
On 27/04/2022 14:34, Jan Beulich wrote:
> On 27.04.2022 15:22, Julien Grall wrote:
>> --- a/SUPPORT.md
>> +++ b/SUPPORT.md
>> @@ -50,9 +50,10 @@ For the Cortex A57 r0p0 - r1p1, see Errata 832075.
>>
>> ### Physical Memory
>>
>> - Status: Supported up to 8 TiB
>> -
>> -Hosts with more memory are supported, but not security supported.
>> + Status, x86: Supported up to 8 TiB. Hosts with more memory are
>> + supported but not security support.
>
> Nit: "supported" also in the 2nd instance, as it was before. I think
> retaining the comma would also be beneficial.
Agree for both. Sorry, I rewrote the sentence rather than copying/pasting.
>
>> + Status, Arm32: Supported up to 12 GiB
>> + Status, Arm64: Supported up to 2 TiB
>
> This really will need to be ack-ed by an Arm person, so I don't see
> value in me providing an ack.
Bertrand and Stefanos should be CCed. I will wait input from them before
resending a new version.
Cheers,
--
Julien Grall
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm
2022-04-27 13:22 [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm Julien Grall
2022-04-27 13:34 ` Jan Beulich
@ 2022-04-27 13:51 ` Bertrand Marquis
2022-05-05 10:47 ` Julien Grall
1 sibling, 1 reply; 5+ messages in thread
From: Bertrand Marquis @ 2022-04-27 13:51 UTC (permalink / raw)
To: Julien Grall
Cc: Xen-devel, Julien Grall, Andrew Cooper, George Dunlap,
Jan Beulich, Stefano Stabellini, Wei Liu
Hi Julien,
> On 27 Apr 2022, at 14:22, Julien Grall <julien@xen.org> wrote:
>
> From: Julien Grall <jgrall@amazon.com>
>
> As part of XSA-385, SUPPORT.MD gained a statement regarding the amount
> of physical memory supported.
>
> However, booting Xen on a Arm platform with that amount of memory would
> result to a breakage because the frametable area is too small.
>
> The wiki [1] (as of April 2022) claims we were able to support up to
> 5 TiB on Arm64 and 16 GiB. However, this is not the case because
> the struct page_info has always been bigger than expected (56 bytes
> for 64-bit and 32-bytes for 32-bit).
>
> I don't have any HW with such amount of memory. So rather than
> modifying the code, take the opportunity to use the limit that should
> work on Arm (2 TiB for 64-bit and 12 GiB for 32-bit).
Sadly I have no hardware either even remotely near this capacity and
I think those limits are right for now so...
>
> Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com> #arm part
Cheers
Bertrand
> ---
> SUPPORT.md | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/SUPPORT.md b/SUPPORT.md
> index 088dda9561c1..1e3c69a07615 100644
> --- a/SUPPORT.md
> +++ b/SUPPORT.md
> @@ -50,9 +50,10 @@ For the Cortex A57 r0p0 - r1p1, see Errata 832075.
>
> ### Physical Memory
>
> - Status: Supported up to 8 TiB
> -
> -Hosts with more memory are supported, but not security supported.
> + Status, x86: Supported up to 8 TiB. Hosts with more memory are
> + supported but not security support.
> + Status, Arm32: Supported up to 12 GiB
> + Status, Arm64: Supported up to 2 TiB
>
> ### Physical Memory Hotplug
>
> --
> 2.32.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm
2022-04-27 13:51 ` Bertrand Marquis
@ 2022-05-05 10:47 ` Julien Grall
0 siblings, 0 replies; 5+ messages in thread
From: Julien Grall @ 2022-05-05 10:47 UTC (permalink / raw)
To: Bertrand Marquis
Cc: Xen-devel, Julien Grall, Andrew Cooper, George Dunlap,
Jan Beulich, Stefano Stabellini, Wei Liu
On 27/04/2022 14:51, Bertrand Marquis wrote:
> Hi Julien,
Hi Bertrand,
>> On 27 Apr 2022, at 14:22, Julien Grall <julien@xen.org> wrote:
>>
>> From: Julien Grall <jgrall@amazon.com>
>>
>> As part of XSA-385, SUPPORT.MD gained a statement regarding the amount
>> of physical memory supported.
>>
>> However, booting Xen on a Arm platform with that amount of memory would
>> result to a breakage because the frametable area is too small.
>>
>> The wiki [1] (as of April 2022) claims we were able to support up to
>> 5 TiB on Arm64 and 16 GiB. However, this is not the case because
>> the struct page_info has always been bigger than expected (56 bytes
>> for 64-bit and 32-bytes for 32-bit).
>>
>> I don't have any HW with such amount of memory. So rather than
>> modifying the code, take the opportunity to use the limit that should
>> work on Arm (2 TiB for 64-bit and 12 GiB for 32-bit).
>
> Sadly I have no hardware either even remotely near this capacity and
> I think those limits are right for now so...
>
>>
>> Signed-off-by: Julien Grall <jgrall@amazon.com>
> Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com> #arm part
Thanks! The changes requested by Jan are easy to fix. So instead of
resubmitting, I have done the modifications and committed the patch
directly.
Cheers,
--
Julien Grall
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-05-05 10:47 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-27 13:22 [PATCH] SUPPORT.MD: Correct the amount of physical memory supported for Arm Julien Grall
2022-04-27 13:34 ` Jan Beulich
2022-04-27 13:39 ` Julien Grall
2022-04-27 13:51 ` Bertrand Marquis
2022-05-05 10:47 ` Julien Grall
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