Re: [PATCH 1/4] expand x86 arch_shared_info to support linear p2m list

["Jürgen Groß" <jgross@suse.com>]

On 11/21/2014 02:26 PM, Andrew Cooper wrote:
> On 21/11/14 12:57, Juergen Gross wrote:
>> On 11/21/2014 01:23 PM, Jan Beulich wrote:
>>>>>> On 14.11.14 at 10:37, <"jgross@suse.com".non-mime.internet> wrote:
>>>> --- a/xen/include/public/arch-x86/xen.h
>>>> +++ b/xen/include/public/arch-x86/xen.h
>>>> @@ -224,7 +224,12 @@ struct arch_shared_info {
>>>>        /* Frame containing list of mfns containing list of mfns
>>>> containing p2m. */
>>>>        xen_pfn_t     pfn_to_mfn_frame_list_list;
>>>>        unsigned long nmi_reason;
>>>> -    uint64_t pad[32];
>>>> +    /*
>>>> +     * Following two fields are valid if pfn_to_mfn_frame_list_list
>>>> contains
>>>> +     * ~0UL.
>>>> +     */
>>>> +    unsigned long p2m_vaddr;    /* virtual address of the p2m list */
>>>> +    unsigned long p2m_as_root;  /* mfn of the top level page table */
>>>
>>> xen_pfn_t please. And what does the "as" in the name stand for?
>>
>> "as" is address space. I can rename it to e.g. "p2m_pgd_mfn".
>
> That is a linuxism in naming, which is also not accurate.
>
>  From my understanding, this frame must be an L4 table for 64bit guests,
> and an L3 table for 32bit guests.  I.e. it is effectively a cr3 with
> which to use the p2m_vaddr field above?

Okay, so p2m_cr3 then?


Juergen