Re: [PATCH 7/8] x86: Enable 5-level paging support

From: Juergen Gross
Date: Thu Apr 06 2017 - 11:57:08 EST


On 06/04/17 17:24, Kirill A. Shutemov wrote:
> On Thu, Apr 06, 2017 at 04:52:11PM +0200, Juergen Gross wrote:
>> On 06/04/17 16:01, Kirill A. Shutemov wrote:
>>> Most of things are in place and we can enable support of 5-level paging.
>>>
>>> Enabling XEN with 5-level paging requires more work. The patch makes XEN
>>> dependent on !X86_5LEVEL.
>>>
>>> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
>>> ---
>>> arch/x86/Kconfig | 5 +++++
>>> arch/x86/xen/Kconfig | 1 +
>>> 2 files changed, 6 insertions(+)
>>>
>>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>>> index 4e153e93273f..7a76dcac357e 100644
>>> --- a/arch/x86/Kconfig
>>> +++ b/arch/x86/Kconfig
>>> @@ -318,6 +318,7 @@ config FIX_EARLYCON_MEM
>>>
>>> config PGTABLE_LEVELS
>>> int
>>> + default 5 if X86_5LEVEL
>>> default 4 if X86_64
>>> default 3 if X86_PAE
>>> default 2
>>> @@ -1390,6 +1391,10 @@ config X86_PAE
>>> has the cost of more pagetable lookup overhead, and also
>>> consumes more pagetable space per process.
>>>
>>> +config X86_5LEVEL
>>> + bool "Enable 5-level page tables support"
>>> + depends on X86_64
>>> +
>>> config ARCH_PHYS_ADDR_T_64BIT
>>> def_bool y
>>> depends on X86_64 || X86_PAE
>>> diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
>>> index 76b6dbd627df..b90d481ce5a1 100644
>>> --- a/arch/x86/xen/Kconfig
>>> +++ b/arch/x86/xen/Kconfig
>>> @@ -5,6 +5,7 @@
>>> config XEN
>>> bool "Xen guest support"
>>> depends on PARAVIRT
>>> + depends on !X86_5LEVEL
>>> select PARAVIRT_CLOCK
>>> select XEN_HAVE_PVMMU
>>> select XEN_HAVE_VPMU
>>>
>>
>> Just a heads up: this last change will conflict with the Xen tree.
>
> It should be trivial to fix, right? It's one-liner after all.

Right. Just wanted to mention it.


Juergen