Re: [PATCH] xen: Add GS base to HVM VCPU context

[Aravindh Puthiyaparambil <aravindh@virtuata.com>]

On Mon, Apr 23, 2012 at 12:53 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>> On 23.04.12 at 09:47, Aravindh Puthiyaparambil <aravindh@virtuata.com> wrote:
>> On Apr 23, 2012 12:41 AM, "Jan Beulich" <JBeulich@suse.com> wrote:
>>>
>>> >>> On 21.04.12 at 02:58, Aravindh Puthiyaparambil <aravindh@virtuata.com>
>> wrote:
>>> > Add GS base to the HVM VCPU context returned by xc_vcpu_getcontext()
>>> >
>>> > Signed-off-by: Aravindh Puthiyaparambil <aravindh@virtuata.com>
>>> >
>>> > diff -r e62ab14d44af -r babbb3e0f4d3 xen/arch/x86/domctl.c
>>> > --- a/xen/arch/x86/domctl.c   Fri Apr 20 11:36:02 2012 -0700
>>> > +++ b/xen/arch/x86/domctl.c   Fri Apr 20 17:55:49 2012 -0700
>>> > @@ -1592,6 +1592,12 @@ void arch_get_info_guest(struct vcpu *v,
>>> >          c.nat->user_regs.fs = sreg.sel;
>>> >          hvm_get_segment_register(v, x86_seg_gs, &sreg);
>>> >          c.nat->user_regs.gs = sreg.sel;
>>> > +#ifdef __x86_64__
>>> > +        if ( ring_0(&c.nat->user_regs) )
>>> > +            c.nat->gs_base_kernel = sreg.base;
>>> > +        else
>>> > +            c.nat->gs_base_user = sreg.base;
>>> > +#endif
>>>
>>> If you do anything like this, do it completely please (i.e. fill all three
>>> base address fields instead of just one).
>>>
>>
>> Sure. I was not sure if it was ok to add fields to the vcpu context
>> structure which is why I didn't do it across the board. I will do so and
>> resubmit.
>
> I don't see what fields you would need to add.

Don't I need to add ss_base, cs_base, es_base, ds_base to
vcpu_guest_context? I am assuming both 32-bit and 64-bit cases.

Aravindh