Re: Domain0/Domain 1 and ring1 (x86) - tracing question

[John Que <qwejohn@gmail.com>]

Hello,

Thanks !

This makes clear things a bit. 

However, I had grepped under the linux-2.6-xen-sparse tree and 
saw only one occurrence of  BOOT_CS , in that
linux-2.6-xen-sparse/include/asm-xen/asm-i386/segment.h.

I had also grepped under the "xen" (hypervisor) subtree and did not 
find and also under linux-2.6.12-xen0/arch/xen and did not find any
occurrence of  BOOT_CS.

(There is of course in linux-2.6.12-xen0/arch/xen/i386/boot/setup.S , 
but this seems unrelevant in our case).

I am probably missing something;
 Any ideas ? 

Regards,
John

On 8/16/05, Petersson, Mats <mats.petersson@amd.com> wrote:
> There's a #define in arch-x86_32.h that defines FLAT_KERNEL_[CDS]S to
> FLAT_RING1_[CDS]S. FLAT_RING1_[CDS]S is the entry in GDT for a CPL=1
> (ring 1) code/data/stack[1] segment selector.
> It is then used in various places to set up the registers used by the
> actual kernel, for example the file
> linux-2.6-xen-sparse/include/asm-xen/asm-i386/segment.h is using the
> KERNEL_CS to give the BOOT_CS to the Linux kernel.
> 
> [1] Stack segment is actually using the same selector as the data
> segment.
> 
> --
> Mats
> 
> > -----Original Message-----
> > From: xen-devel-bounces@lists.xensource.com
> > [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of John Que
> > Sent: 16 August 2005 11:59
> > To: xen-devel@lists.xensource.com
> > Subject: [Xen-devel] Domain0/Domain 1 and ring1 (x86) -
> > tracing question
> >
> > Hello,
> > As I understand the Hypervisor should run in Ring 0 of the
> > x86 , and the domains (Domain0 and DomainU) should work in Ring 1.
> >
> > I was a bit curious where in the code this assiging of Ring 0
> > to Xen and Ring 1 to dom0/domU is done ?
> > I had tried to look under arch/xen/i386 and didn't find.
> >
> > Is it in the assembler *.S files ?
> >
> > Regards,
> > John
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xensource.com
> > http://lists.xensource.com/xen-devel
> >
> 
>