From: Gordan Bobic <gordan@bobich.net>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Subject: Re: HVM support for e820_host (Was: Bug: Limitation of <=2GB RAM in domU persists with 4.3.0)
Date: Thu, 05 Sep 2013 23:42:38 +0100 [thread overview]
Message-ID: <522908DE.70504@bobich.net> (raw)
In-Reply-To: <f7369807-5250-4621-bce4-668013404582@email.android.com>
On 09/05/2013 11:23 PM, Konrad Rzeszutek Wilk wrote:
> Gordan Bobic <gordan@bobich.net> wrote:
>> Right, finally got around to trying this with the latest patch.
>>
>> With e820_host=0 things work as before:
>>
>> (XEN) HVM3: BIOS map:
>> (XEN) HVM3: f0000-fffff: Main BIOS
>> (XEN) HVM3: E820 table:
>> (XEN) HVM3: [00]: 00000000:00000000 - 00000000:0009e000: RAM
>> (XEN) HVM3: [01]: 00000000:0009e000 - 00000000:000a0000: RESERVED
>> (XEN) HVM3: HOLE: 00000000:000a0000 - 00000000:000e0000
>> (XEN) HVM3: [02]: 00000000:000e0000 - 00000000:00100000: RESERVED
>> (XEN) HVM3: [03]: 00000000:00100000 - 00000000:e0000000: RAM
>> (XEN) HVM3: HOLE: 00000000:e0000000 - 00000000:fc000000
>> (XEN) HVM3: [04]: 00000000:fc000000 - 00000001:00000000: RESERVED
>> (XEN) HVM3: [05]: 00000001:00000000 - 00000002:1f800000: RAM
>>
>>
>> I seem to be getting two different E820 table dumps with e820_host=1:
>>
>> (XEN) HVM1: BIOS map:
>> (XEN) HVM1: f0000-fffff: Main BIOS
>> (XEN) HVM1: build_e820_table:91 got 8 op.nr_entries
>> (XEN) HVM1: E820 table:
>> (XEN) HVM1: [00]: 00000000:00000000 - 00000000:3f790000: RAM
>> (XEN) HVM1: [01]: 00000000:3f790000 - 00000000:3f79e000: ACPI
>> (XEN) HVM1: [02]: 00000000:3f79e000 - 00000000:3f7d0000: NVS
>> (XEN) HVM1: [03]: 00000000:3f7d0000 - 00000000:3f7e0000: RESERVED
>> (XEN) HVM1: HOLE: 00000000:3f7e0000 - 00000000:3f7e7000
>> (XEN) HVM1: [04]: 00000000:3f7e7000 - 00000000:40000000: RESERVED
>> (XEN) HVM1: HOLE: 00000000:40000000 - 00000000:fee00000
>> (XEN) HVM1: [05]: 00000000:fee00000 - 00000000:fee01000: RESERVED
>> (XEN) HVM1: HOLE: 00000000:fee01000 - 00000000:ffc00000
>> (XEN) HVM1: [06]: 00000000:ffc00000 - 00000001:00000000: RESERVED
>> (XEN) HVM1: [07]: 00000001:00000000 - 00000001:68870000: RAM
>> (XEN) HVM1: E820 table:
>> (XEN) HVM1: [00]: 00000000:00000000 - 00000000:0009e000: RAM
>> (XEN) HVM1: [01]: 00000000:0009e000 - 00000000:000a0000: RESERVED
>> (XEN) HVM1: HOLE: 00000000:000a0000 - 00000000:000e0000
>> (XEN) HVM1: [02]: 00000000:000e0000 - 00000000:00100000: RESERVED
>> (XEN) HVM1: [03]: 00000000:00100000 - 00000000:a7800000: RAM
>> (XEN) HVM1: HOLE: 00000000:a7800000 - 00000000:fc000000
>> (XEN) HVM1: [04]: 00000000:fc000000 - 00000001:00000000: RESERVED
>> (XEN) HVM1: Invoking ROMBIOS ...
>>
>> I cannot quite figure out what is going on here - these tables can't
>> both be true.
>>
>
> Right. The code just prints the E820 that was constructed b/c of the e820_host =1 parameter as the first output. Then the second one is what was constructed originally.
>
> The code that would tie in the E820 from the hyper call and the alter how the hvmloader sets it up is not yet done.
>
>
>> Looking at the IOMEM on the host, the IOMEM begins at 0xa8000000 and
>> goes more or less contiguously up to 0xfec8b000.
>>
>> Looking at dmesg on domU, the e820 map more or less matches the second
>> dump above.
>
> Right. That is correct since the patch I sent just outputs stuff. No real changes to the E820 yet.
/me *facepalms*
That indeed explains everything. :)
But having had a thorough look through the memory mappings (see my other
long, rambling email), I don't actually see an obvious area where RAM
might overwrite a dom0 IOMEM range - assuming the "HOLE" part isn't
mapped as RAM in domU.
Or to summarize:
dom0 PCI IOMEM actually has mappings from a8000000 onward, and giving
domU up to that much memory works fine. So the memory stomp must be
happening from a8000000 onward. But - the only things above that address
in domU are the HOLE up to fc000000 and RESERVED up to ffffffff. So no
domU memory is getting mapped into the IOMEM range anyway - which begs
the question of what is _actually_ causing the crash. Stuff I haven't
yet found in domU getting mapped into the a7800000-fc000000 hole
overlapping dom0 IOMEM? SeaBIOS doing smething odd in the
fc000000-fec8b000 range marked RESERVED in domU?
Or am I reading this all wrong?
Gordan
next prev parent reply other threads:[~2013-09-05 22:42 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-23 22:34 Bug: Limitation of <=2GB RAM in domU persists with 4.3.0 Gordan Bobic
2013-07-24 14:08 ` Konrad Rzeszutek Wilk
2013-07-24 14:17 ` Gordan Bobic
2013-07-24 16:06 ` Konrad Rzeszutek Wilk
2013-07-24 16:14 ` Gordan Bobic
2013-07-24 16:31 ` Konrad Rzeszutek Wilk
2013-07-24 17:26 ` Gordan Bobic
2013-07-24 22:15 ` Gordan Bobic
2013-07-25 19:18 ` George Dunlap
2013-07-25 21:48 ` Gordan Bobic
2013-07-25 22:23 ` Gordan Bobic
2013-07-26 0:21 ` Ian Campbell
2013-07-26 1:15 ` Andrew Bobulsky
2013-07-26 9:28 ` Gordan Bobic
2013-07-26 13:11 ` Gordan Bobic
2013-07-31 17:53 ` George Dunlap
2013-07-31 17:56 ` Andrew Cooper
2013-07-31 19:36 ` Gordan Bobic
2013-07-31 19:35 ` Gordan Bobic
2013-08-01 9:15 ` George Dunlap
2013-08-01 13:10 ` Fabio Fantoni
2013-08-02 14:43 ` George Dunlap
2013-07-28 10:26 ` Konrad Rzeszutek Wilk
2013-07-28 21:24 ` Gordan Bobic
2013-07-28 23:17 ` Konrad Rzeszutek Wilk
2013-07-28 23:30 ` Gordan Bobic
2013-07-29 9:53 ` Ian Campbell
2013-07-26 9:23 ` Gordan Bobic
2013-07-29 11:14 ` Ian Campbell
2013-07-29 18:04 ` Konrad Rzeszutek Wilk
2013-09-03 13:53 ` Gordan Bobic
2013-09-03 14:59 ` Konrad Rzeszutek Wilk
2013-09-03 19:47 ` HVM support for e820_host (Was: Bug: Limitation of <=2GB RAM in domU persists with 4.3.0) Gordan Bobic
2013-09-03 20:35 ` Gordan Bobic
2013-09-03 20:49 ` Gordan Bobic
2013-09-03 21:10 ` Konrad Rzeszutek Wilk
2013-09-03 21:24 ` Gordan Bobic
2013-09-03 21:30 ` Konrad Rzeszutek Wilk
2013-09-04 0:18 ` Gordan Bobic
2013-09-04 14:08 ` Konrad Rzeszutek Wilk
2013-09-04 14:23 ` Gordan Bobic
2013-09-04 18:00 ` Konrad Rzeszutek Wilk
2013-09-03 21:08 ` Konrad Rzeszutek Wilk
2013-09-04 9:21 ` Gordan Bobic
2013-09-04 11:01 ` Gordan Bobic
2013-09-04 13:11 ` Gordan Bobic
2013-09-04 20:18 ` Gordan Bobic
2013-09-05 2:04 ` Konrad Rzeszutek Wilk
2013-09-05 9:41 ` Gordan Bobic
2013-09-05 10:00 ` Gordan Bobic
2013-09-05 12:36 ` Konrad Rzeszutek Wilk
2013-09-05 10:26 ` Gordan Bobic
2013-09-05 12:38 ` Konrad Rzeszutek Wilk
2013-09-05 21:13 ` Gordan Bobic
2013-09-05 21:29 ` Gordan Bobic
2013-09-05 21:46 ` Gordan Bobic
2013-09-05 22:23 ` Konrad Rzeszutek Wilk
2013-09-05 22:42 ` Gordan Bobic [this message]
2013-09-06 13:09 ` Konrad Rzeszutek Wilk
2013-09-06 14:09 ` Gordan Bobic
2013-09-05 22:45 ` Gordan Bobic
2013-09-05 23:01 ` Konrad Rzeszutek Wilk
2013-09-06 12:23 ` Gordan Bobic
2013-09-06 13:20 ` Konrad Rzeszutek Wilk
2013-09-06 14:45 ` Gordan Bobic
2013-09-05 22:33 ` Gordan Bobic
2013-09-06 13:04 ` Konrad Rzeszutek Wilk
2013-09-06 13:34 ` Gordan Bobic
2013-09-06 14:32 ` Konrad Rzeszutek Wilk
2013-09-06 16:30 ` Gordan Bobic
2013-09-06 19:54 ` Gordan Bobic
2013-09-10 13:35 ` Konrad Rzeszutek Wilk
2013-09-10 15:04 ` Gordan Bobic
2013-07-25 21:26 ` Bug: Limitation of <=2GB RAM in domU persists with 4.3.0 Gordan Bobic
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=522908DE.70504@bobich.net \
--to=gordan@bobich.net \
--cc=konrad.wilk@oracle.com \
--cc=xen-devel@lists.xen.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).