Re: [Xen-devel] [PATCH v3] docs: add PVH specification

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On September 22, 2014 7:16:26 AM EDT, Jan Beulich <JBeulich@xxxxxxxx> wrote:
>>>> On 20.09.14 at 21:15, <konrad.wilk@xxxxxxxxxx> wrote:
>> On Thu, Sep 18, 2014 at 07:19:24PM +0200, Roger Pau Monne wrote:
>>> +All the segments selectors are set with a flat base at zero.
>>> +
>>> +The `cs` segment selector attributes are set to 0x0a09b, which
>describes an
>>> +executable and readable code segment only accessible by the most
>privileged
>>> +level. The segment is also set as a 64-bit code segment (`L` flag
>set, `D` flag
>>> +unset).
>>> +
>>> +The remaining segment selectors (`ds`, `ss`, `es`, `fs` and `gs`)
>are all set
>>> +to the same values. The attributes are set to 0x0c093, which
>implies a read and
>>> +write data segment only accessible by the most privileged level.
>> 
>> I think the SS, ES, FS, GS are set to the null selector in 64-bit
>mode.
>
>Right - with their hidden portions set to what is being said in
>Roger's description.

Correct. I should clarify - I meant that we should say what the selector value 
is expected to be. And on 64bit it is 0 (aka NULL selector). Not the segment 
values.

Thought maybe that is pointless as the AMD 64 manual is pretty clear that 
without that being set to zero we will get an exception.

>
>Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel