Re: [Xen-devel] [PATCH] [Xen] Check FADT's signature

[Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>]

Okay, please try tip of staging tree (c/s 15773).

 -- Keir

On 24/8/07 07:19, "Stefan Berger" <stefanb@xxxxxxxxxx> wrote:

> xen-devel-bounces@xxxxxxxxxxxxxxxxxxx wrote on 08/10/2007 09:15:57 PM:
>
> > A good debugging approach will be to write a function that walks the
> > pagetables for that virtual address and prints the PTE that maps it.
> > Scatter calls to this function between acpi_boot_table_init() and 
> > acpi_boot_init() and hence narrow down exactly where the PTE is 
> > getting zapped. 
>
> What is happening is that the pl1e pointer used for mapping the ACPI table entry changes between the calls before paging_init() and after. The l1_pgentry_t that is used before paging_init() correctly shows that the page is present whereas the one used after indicates that the page is not present. Then when the ACPI table is mapped after paging_init() the tlb is not flushed and wrong information is read. 
>
>    Stefan 
>
> > 
> >  -- Keir
> > 
> > On 10/8/07 19:21, "Keir Fraser" <keir@xxxxxxxxxxxxx> wrote:
>
> > On 10/8/07 18:00, "Stefan Berger" <stefanb@xxxxxxxxxx> wrote:
>
> > (XEN) map_pages_to_xen : 3533                                     
> > (that's the line number)
> > (XEN) 0xfff9b000 was NOT present. 
> > 
> > Something between (*) and here seems to trash this presence flag. 
> > paging_init() and many others lie in between the upper call and this
> > one here. Could be a side effect of this? Maybe that tlb flush at 
> > the right place in one of these functions would solve the problem? 
> > 
> > Yes, this now looks likely and that’s rather scary. We’ll go after 
> > this next week. 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel




_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel