From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Que Subject: Re: Domain0/Domain 1 and ring1 (x86) - tracing question Date: Tue, 16 Aug 2005 10:30:25 -0400 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Petersson, Mats" Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Hello, Thanks ! This makes clear things a bit.=20 However, I had grepped under the linux-2.6-xen-sparse tree and=20 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=20 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 ,=20 but this seems unrelevant in our case). I am probably missing something; Any ideas ?=20 Regards, John On 8/16/05, Petersson, Mats 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=3D1 > (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. >=20 > [1] Stack segment is actually using the same selector as the data > segment. >=20 > -- > Mats >=20 > > -----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 > > >=20 >