From mboxrd@z Thu Jan  1 00:00:00 1970
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Subject: Re: HVMlite ABI specification DRAFT A
Date: Thu, 4 Feb 2016 23:41:48 +0100
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To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Tim Deegan <tim@xen.org>, Paul Durrant <paul.durrant@citrix.com>, David Vrabel <david.vrabel@citrix.com>, Jan Beulich <JBeulich@suse.com>, xen-devel <xen-devel@lists.xenproject.org>, Boris Ostrovsky <boris.ostrovsky@oracle.com>, Roger Pau =?iso-8859-1?Q?Monn=E9?= <roger.pau@citrix.com>
List-Id: xen-devel@lists.xenproject.org

Andrew Cooper, on Thu 04 Feb 2016 22:25:47 +0000, wrote:
> On 04/02/2016 22:21, Samuel Thibault wrote:
> > Boris Ostrovsky, on Thu 04 Feb 2016 14:18:46 -0500, wrote:
> >> On 02/04/2016 02:09 PM, Samuel Thibault wrote:
> >>> Roger Pau Monn=E9, on Thu 04 Feb 2016 18:48:14 +0100, wrote:
> >>>>     struct hvm_start_info {
> >>>>     #define HVM_START_MAGIC_VALUE 0x336ec578
> >>>>         uint32_t magic;             /* Contains the magic value 0x33=
6ec578       */
> >>>>                                     /* ("xEn3" with the 0x80 bit of =
the "E" set).*/
> >>>>         uint32_t flags;             /* SIF_xxx flags.               =
             */
> >>>>         uint32_t cmdline_paddr;     /* Physical address of the comma=
nd line.     */
> >>>>         uint32_t nr_modules;        /* Number of modules passed to t=
he kernel.   */
> >>>>         uint32_t modlist_paddr;     /* Physical address of an array =
of           */
> >>>>                                     /* hvm_modlist_entry.           =
             */
> >>>>     };
> >>> Mmm, don't we also need a description of the initial page table, so t=
hat
> >>> the guest kernel knows which part of the memory it shouldn't use until
> >>> having initialized its own page table?  Or is there none in the guest
> >>> physical memory at startup of HVMlite mode?
> >> We start with paging off.
> > So a 32bit hypervisor *has* to use segmentation to protect itself from
> > domU?
> =

> This is an HVM domain, so uses hardware virtualisation extensions.  It
> is not like a PV guest.

Ah, right, sorry, too much used to PV :)

Samuel