Re: [PATCH 2/2] xen: Kconfig: nest Xen guest options

2020-10-15 Thread Jason Andryuk
On Thu, Oct 15, 2020 at 5:42 AM Jürgen Groß  wrote:
>
> On 14.10.20 19:53, Jason Andryuk wrote:
> > Moving XEN_512GB allows it to nest under XEN_PV.  That also allows
> > XEN_PVH to nest under XEN as a sibling to XEN_PV and XEN_PVHVM giving:
> >
> > [*]   Xen guest support
> > [*] Xen PV guest support
> > [*]   Limit Xen pv-domain memory to 512GB
> > [*]   Xen PV Dom0 support
>
> This has currently a wrong text/semantics:
>
> It should be split to CONFIG_XEN_DOM0 and CONFIG_XEN_PV_DOM0.
>
> Otherwise the backends won't be enabled per default for a PVH-only
> config meant to be Dom0-capable.
>
> You don't have to do that in your patches if you don't want to, but
> I wanted to mention it with you touching this area of Kconfig.

Yes, good point.  I had not considered that.

> > [*] Xen PVHVM guest support
> > [*] Xen PVH guest support
> >
> > Signed-off-by: Jason Andryuk 
>
> Reviewed-by: Juergen Gross 

Thanks,
Jason


Re: [PATCH 2/2] xen: Kconfig: nest Xen guest options

2020-10-15 Thread Jason Andryuk
On Thu, Oct 15, 2020 at 9:17 AM  wrote:
>
>
> On 10/15/20 9:10 AM, Andrew Cooper wrote:
> > On 15/10/2020 13:37, boris.ostrov...@oracle.com wrote:
> >> On 10/14/20 1:53 PM, Jason Andryuk wrote:
> >>> +config XEN_512GB
> >>> +   bool "Limit Xen pv-domain memory to 512GB"
> >>> +   depends on XEN_PV && X86_64
> >> Why is X86_64 needed here?
> >> 512G support was implemented using a direct-mapped P2M, and is rather
> > beyond the virtual address capabilities of 32bit.
> >
>
> Yes, my point was that XEN_PV already depends on X86_64.

Oh, thanks for catching this.  I re-introduced it by accident when
rebasing the patches.

Regards,
Jason


Re: [PATCH 2/2] xen: Kconfig: nest Xen guest options

2020-10-15 Thread boris . ostrovsky


On 10/15/20 9:10 AM, Andrew Cooper wrote:
> On 15/10/2020 13:37, boris.ostrov...@oracle.com wrote:
>> On 10/14/20 1:53 PM, Jason Andryuk wrote:
>>> +config XEN_512GB
>>> +   bool "Limit Xen pv-domain memory to 512GB"
>>> +   depends on XEN_PV && X86_64
>> Why is X86_64 needed here?
>> 512G support was implemented using a direct-mapped P2M, and is rather
> beyond the virtual address capabilities of 32bit.
>

Yes, my point was that XEN_PV already depends on X86_64.


-boris



Re: [PATCH 2/2] xen: Kconfig: nest Xen guest options

2020-10-15 Thread Andrew Cooper
On 15/10/2020 13:37, boris.ostrov...@oracle.com wrote:
> On 10/14/20 1:53 PM, Jason Andryuk wrote:
>> +config XEN_512GB
>> +bool "Limit Xen pv-domain memory to 512GB"
>> +depends on XEN_PV && X86_64
>
> Why is X86_64 needed here?

>512G support was implemented using a direct-mapped P2M, and is rather
beyond the virtual address capabilities of 32bit.

~Andrew


Re: [PATCH 2/2] xen: Kconfig: nest Xen guest options

2020-10-15 Thread boris . ostrovsky


On 10/14/20 1:53 PM, Jason Andryuk wrote:
> +config XEN_512GB
> + bool "Limit Xen pv-domain memory to 512GB"
> + depends on XEN_PV && X86_64


Why is X86_64 needed here?


-boris





Re: [PATCH 2/2] xen: Kconfig: nest Xen guest options

2020-10-15 Thread Jürgen Groß

On 14.10.20 19:53, Jason Andryuk wrote:

Moving XEN_512GB allows it to nest under XEN_PV.  That also allows
XEN_PVH to nest under XEN as a sibling to XEN_PV and XEN_PVHVM giving:

[*]   Xen guest support
[*] Xen PV guest support
[*]   Limit Xen pv-domain memory to 512GB
[*]   Xen PV Dom0 support


This has currently a wrong text/semantics:

It should be split to CONFIG_XEN_DOM0 and CONFIG_XEN_PV_DOM0.

Otherwise the backends won't be enabled per default for a PVH-only
config meant to be Dom0-capable.

You don't have to do that in your patches if you don't want to, but
I wanted to mention it with you touching this area of Kconfig.


[*] Xen PVHVM guest support
[*] Xen PVH guest support

Signed-off-by: Jason Andryuk 


Reviewed-by: Juergen Gross 


Juergen