Re: [Xen-devel] Patches for stable

[George Dunlap <dunlapg@xxxxxxxxx>]

On Thu, Apr 5, 2018 at 2:06 PM, Juergen Gross <jgross@xxxxxxxx> wrote:
> On 05/04/18 15:00, Boris Ostrovsky wrote:
>> On 04/05/2018 08:19 AM, Juergen Gross wrote:
>>> On 05/04/18 12:06, George Dunlap wrote:
>>>
>>>> Aren't there flags in the binary somewhere that could tell the
>>>> toolstack / Xen whether the kernel in question needs the RSDP table in
>>>> lowmem, or whether it can be put higher?
>>> Not really. Analyzing the binary whether it accesses the rsdp_addr in
>>> the start_info isn't the way to go, IMO.
>>>
>>> I've sent a patch to xen-devel adding a quirk flag to the domain's
>>> config to enable the admin special casing such an "old" kernel.
>>
>> Can we backport latest struct hvm_start_info changes (which bumped
>> interface version) to 4.11 and pass RSDP only for versions >=1?
>
> And this would help how?
>
> RSDP address is passed today, the kernel just doesn't read it. And
> how should Xen know which interface version the kernel is supporting?
> And Xen needs to know that in advance in order to place the RSDP in
> low memory in case the kernel isn't reading the RSDP address from
> start_info.

But the kernel image has ELF notes, right?  You can put one that
indicates that this binary *does* know how to read the RSDP from the
start_info, and if you don't find that, put it in lowmem.

 -George

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel