Re: dmidecode doesn't work under xen 4.1.1 on certain hardware

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

[-- Attachment #1: Type: text/plain, Size: 3070 bytes --]

On Mon, Sep 26, 2011 at 03:48:52PM +0100, Anthony Wright wrote:
> On 26/09/2011 15:13, Konrad Rzeszutek Wilk wrote:
> > On Fri, Sep 23, 2011 at 03:49:47PM +0100, Anthony Wright wrote:
> >> On 23/09/2011 14:32, Konrad Rzeszutek Wilk wrote:
> >>> On Fri, Sep 23, 2011 at 12:22:04PM +0100, Anthony Wright wrote:
> >>>> I have a xen 4.1.1 with a 3.0.4 linux kernel running on a Supermicro
> >>>> Supermicro X8DTL-iF motherboard with 16GB of RAM.
> >>>>
> >>>> If I run the 3.0.4 kernel on the bare metal dmidecode works fine. If I
> >>> Can you attach the beginning of the kernel bootup log? It should
> >>> have some entry about 1-1 mappings. Make sure to run Linux with "debug loglevel=8"
> >> Please find attached.
> >> 2011 Sep 23 14:45:41 kernel: [    0.000000] 1-1 mapping on 9a->100
> >> 2011 Sep 23 14:45:41 kernel: [    0.000000] 1-1 mapping on bf780->100000
> >> 2011 Sep 23 14:45:41 kernel: [    0.000000] Set 264422 page(s) to 1-1 mapping.
> >> 2011 Sep 23 14:45:41 kernel: [    0.000000] BIOS-provided physical RAM map:
> >> 2011 Sep 23 14:45:41 kernel: [    0.000000]  Xen: 0000000000000000 - 0000000000099000 (usable)
> >> 2011 Sep 23 14:45:41 kernel: [    0.000000]  Xen: 0000000000099800 - 0000000000100000 (reserved)
> > .. snip..
> >
> > So 99C00 is right at cusp of 'usuable' and 'reserved'. Meaning that region
> > falls within the 4KB page. And we did not set the 1-1 mapping for 99 (we
> > started at 9A).
> >
> > But now that I think of it - this is Linux E820 which does get modified.
> > Can you also provide  the hypervisor E820 output? You can get 'xl dmesg'
> > for that. That should provide the "virgin" output of the e820 which we
> > use for 1-1 mapping.
> I'm not quite sure I understand all that, but I think you would find the
> xl dmesg output helpful, so I've attached it.

Thanks.

>  __  __            _  _    _   _ 
>  \ \/ /___ _ __   | || |  / | / |
>   \  // _ \ '_ \  | || |_ | | | |
>   /  \  __/ | | | |__   _|| |_| |
>  /_/\_\___|_| |_|    |_|(_)_(_)_|
>                                  
> (XEN) Xen version 4.1.1 (@[unknown]) (gcc version 4.4.3 (GCC) ) Wed Sep 21 08:25:36 GMT 2011
> (XEN) Latest ChangeSet: unavailable
> (XEN) Bootloader: GNU GRUB 0.97
> (XEN) Command line: 
> (XEN) Video information:
> (XEN)  VGA is text mode 80x25, font 8x16
> (XEN)  VBE/DDC methods: V2; EDID transfer time: 1 seconds
> (XEN) Disc information:
> (XEN)  Found 4 MBR signatures
> (XEN)  Found 4 EDD information structures
> (XEN) WARNING: Only the first 16 GB of the physical memory map can be accessed by Xen in 32-bit mode.

That bites ^^^^
> (XEN) Truncating RAM from 17825792kB to 16777216kB

> (XEN) Xen-e820 RAM map:
> (XEN)  0000000000000000 - 0000000000099800 (usable)
> (XEN)  0000000000099800 - 00000000000a0000 (reserved)
> (XEN)  00000000000e4000 - 0000000000100000 (reserved)
> (XEN)  0000000000100000 - 00000000bf780000 (usable)
> (XEN)  00000000bf78e000 - 00000000bf790000 type 9

Ok, so this patch should shed some light and potentially fix your problem. Please
try it out and attach the serial log for Linux kernel. Thx.

[-- Attachment #2: e820.patch --]
[-- Type: text/x-diff, Size: 689 bytes --]

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 46d6d21..3368c30 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -166,9 +166,11 @@ static unsigned long __init xen_set_identity(const struct e820entry *list,
 			continue;
 
 		if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
+			printk(KERN_INFO "(%lx->%lx) PCI: %lx->%lx (last %lx, now %lx)\n",
+				start, end, start_pci, start, last, end);
 			if (start > start_pci)
 				identity += set_phys_range_identity(
-						PFN_UP(start_pci), PFN_DOWN(start));
+						PFN_DOWN(start_pci), PFN_DOWN(start));
 
 			/* Without saving 'last' we would gooble RAM too
 			 * at the end of the loop. */

[-- Attachment #3: Type: text/plain, Size: 138 bytes --]

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