From: Ed White <edmund.h.white@intel.com>
To: "Lengyel, Tamas" <tlengyel@novetta.com>
Cc: Ravi Sahita <ravi.sahita@intel.com>,
Wei Liu <wei.liu2@citrix.com>,
Razvan Cojocaru <rcojocaru@bitdefender.com>,
Tim Deegan <tim@xen.org>, Ian Jackson <ian.jackson@eu.citrix.com>,
Xen-devel <xen-devel@lists.xen.org>,
Jan Beulich <jbeulich@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Daniel De Graaf <dgdegra@tycho.nsa.gov>
Subject: Re: [PATCH v2 00/12] Alternate p2m: support multiple copies of host p2m
Date: Wed, 24 Jun 2015 15:55:31 -0700 [thread overview]
Message-ID: <558B3563.9070402@intel.com> (raw)
In-Reply-To: <CAD33N+4WW7cHzLGSHh7LAXmJeTJrTFj--wa-vXnron94WMPLUA@mail.gmail.com>
On 06/24/2015 03:45 PM, Lengyel, Tamas wrote:
> On Wed, Jun 24, 2015 at 6:02 PM, Ed White <edmund.h.white@intel.com> wrote:
>
>> On 06/24/2015 02:34 PM, Lengyel, Tamas wrote:
>>> Hi Ed,
>>> I tried the system using memsharing and I collected the following crash
>>> log. In this test I ran memsharing on all pages of the domain before
>>> activating altp2m and creating the view. Afterwards I used my updated
>>> xen-access to create a copy of this p2m with only R/X permissions. The
>> idea
>>> would be that the altp2m view remains completely shared, while the
>> hostp2m
>>> would be able to do its CoW propagation as the domain is executing.
>>>
>>> (XEN) mm locking order violation: 278 > 239
>>> (XEN) Xen BUG at mm-locks.h:68
>>> (XEN) ----[ Xen-4.6-unstable x86_64 debug=y Tainted: C ]----
>>> (XEN) CPU: 2
>>> (XEN) RIP: e008:[<ffff82d0801f8768>]
>>> p2m_altp2m_propagate_change+0x85/0x4a9
>>> (XEN) RFLAGS: 0000000000010282 CONTEXT: hypervisor (d6v0)
>>> (XEN) rax: 0000000000000000 rbx: 0000000000000000 rcx:
>> 0000000000000000
>>> (XEN) rdx: ffff8302163a8000 rsi: 000000000000000a rdi:
>> ffff82d0802a069c
>>> (XEN) rbp: ffff8302163afa68 rsp: ffff8302163af9e8 r8:
>> ffff83021c000000
>>> (XEN) r9: 0000000000000003 r10: 00000000000000ef r11:
>> 0000000000000003
>>> (XEN) r12: ffff83010cc51820 r13: 0000000000000000 r14:
>> ffff830158d90000
>>> (XEN) r15: 0000000000025697 cr0: 0000000080050033 cr4:
>> 00000000001526f0
>>> (XEN) cr3: 00000000dbba3000 cr2: 00000000778c9714
>>> (XEN) ds: 0000 es: 0000 fs: 0000 gs: 0000 ss: 0000 cs: e008
>>> (XEN) Xen stack trace from rsp=ffff8302163af9e8:
>>> (XEN) ffff8302163af9f8 00000000803180f8 000000000000000c
>> ffff82d0801892ee
>>> (XEN) ffff82d0801fb4d1 ffff83010cc51de0 000000000008ff49
>> ffff82d08012f86a
>>> (XEN) ffff83010cc51820 ffff83010cc51820 0000000000000000
>> 0000000000000000
>>> (XEN) ffff83010cc51820 0000000000000000 ffff8300dbb334b8
>> ffff8302163afa00
>>> (XEN) ffff8302163afb18 ffff82d0801fd549 0000000500000009
>> ffff830200000001
>>> (XEN) 0000000000000001 ffff830158d90000 0000000000000002
>> 000000000008ff49
>>> (XEN) 0000000000025697 000000000000000c ffff8302163afae8
>> 80c000008ff49175
>>> (XEN) 80c00000d0a97175 01ff83010cc51820 0000000000000097
>> ffff8300dbb33000
>>> (XEN) ffff8302163afb78 000000000008ff49 0000000000000000
>> 0000000000000001
>>> (XEN) 0000000000025697 ffff83010cc51820 ffff8302163afb38
>> ffff82d0801fd644
>>> (XEN) ffffffffffffffff 00000000000d0a97 ffff8302163afb98
>> ffff82d0801f23c5
>>> (XEN) ffff830158d90000 000000000cc51820 ffff830158d90000
>> 000000000000000c
>>> (XEN) 000000000008ff49 ffff83010cc51820 0000000000025697
>> 00000000000d0a97
>>> (XEN) 000000000008ff49 ffff830158d90000 ffff8302163afbd8
>> ffff82d0801f45c8
>>> (XEN) ffff83010cc51820 000000000000000c ffff83008fd41170
>> 000000000008ff49
>>> (XEN) 0000000000025697 ffff82e001a152e0 ffff8302163afc58
>> ffff82d080205b51
>>> (XEN) 0000000000000009 000000000008ff49 ffff8300d0a97000
>> ffff83008fd41160
>>> (XEN) ffff82e001a152f0 ffff82e0011fe920 ffff83010cc51820
>> 0000000c00000000
>>> (XEN) 0000000000025697 0000000000000003 ffff83010cc51820
>> ffff8302163afd34
>>> (XEN) 0000000000025697 0000000000000000 ffff8302163afca8
>> ffff82d0801f1f7d
>>> (XEN) Xen call trace:
>>> (XEN) [<ffff82d0801f8768>] p2m_altp2m_propagate_change+0x85/0x4a9
>>> (XEN) [<ffff82d0801fd549>] ept_set_entry_sve+0x5fa/0x6e6
>>> (XEN) [<ffff82d0801fd644>] ept_set_entry+0xf/0x11
>>> (XEN) [<ffff82d0801f23c5>] p2m_set_entry+0xd4/0x112
>>> (XEN) [<ffff82d0801f45c8>] set_shared_p2m_entry+0x2d0/0x39b
>>> (XEN) [<ffff82d080205b51>] __mem_sharing_unshare_page+0x83f/0xbd6
>>> (XEN) [<ffff82d0801f1f7d>] __get_gfn_type_access+0x224/0x2b0
>>> (XEN) [<ffff82d0801c6df5>] hvm_hap_nested_page_fault+0x21f/0x795
>>> (XEN) [<ffff82d0801e86ae>] vmx_vmexit_handler+0x1764/0x1af3
>>> (XEN) [<ffff82d0801ee891>] vmx_asm_vmexit_handler+0x41/0xc0
>>
>> The crash here is because I haven't successfully forced all the shared
>> pages in the host p2m to become unshared before copying,
>> which is the intended behaviour.
>>
>> I think I know how that has happened and how to fix it, but what you're
>> trying to do won't work by design. By the time a copy from host p2m to
>> altp2m occurs, the sharing is supposed to be broken.
>>
>
> Hm. If the sharing gets broken before the hostp2m->altp2m copy, maybe doing
> sharing after the view has been created is a better route? I guess the
> sharing code would need to be adapted to check if altp2m is enabled for
> that to work..
>
>
>>
>> You're coming up with some ways of attempting to use altp2m that we
>> hadn't thought of. That's a good thing, and just what we want, but
>> there are limits to what we can support without more far-reaching
>> changes to existing parts of Xen. This isn't going to be do-able for
>> 4.6.
>>
>
> My main concern is just getting it to work, hitting 4.6 is not a priority.
> I understand that my stuff is highly experimental ;) While the gfn
> remapping feature is intriguing, in my setup I already have a copy of the
> page I would want to present during a singlestep-altp2mswitch - in the
> origin domains memory. AFAIU the gfn remapping would work only within the
> domains existing p2m space.
Understood, but for us hitting 4.6 with the initial version of altp2m
is *the* priority. And yes, remapping is restricted to pages from the
same host p2m.
Ed
next prev parent reply other threads:[~2015-06-24 22:55 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-22 18:56 [PATCH v2 00/12] Alternate p2m: support multiple copies of host p2m Ed White
2015-06-22 18:56 ` [PATCH v2 01/12] VMX: VMFUNC and #VE definitions and detection Ed White
2015-06-24 8:45 ` Andrew Cooper
2015-06-22 18:56 ` [PATCH v2 02/12] VMX: implement suppress #VE Ed White
2015-06-24 9:35 ` Andrew Cooper
2015-06-29 14:20 ` George Dunlap
2015-06-29 14:31 ` Andrew Cooper
2015-06-29 15:03 ` George Dunlap
2015-06-29 16:21 ` Sahita, Ravi
2015-06-29 16:21 ` Ed White
2015-06-22 18:56 ` [PATCH v2 03/12] x86/HVM: Hardware alternate p2m support detection Ed White
2015-06-24 9:44 ` Andrew Cooper
2015-06-24 10:07 ` Jan Beulich
2015-06-22 18:56 ` [PATCH v2 04/12] x86/altp2m: basic data structures and support routines Ed White
2015-06-24 10:06 ` Andrew Cooper
2015-06-24 10:23 ` Jan Beulich
2015-06-24 17:20 ` Ed White
2015-06-24 10:29 ` Andrew Cooper
2015-06-24 11:14 ` Andrew Cooper
2015-06-26 21:17 ` Ed White
2015-06-27 19:25 ` Ed White
2015-06-29 13:00 ` Andrew Cooper
2015-06-29 16:23 ` Ed White
2015-06-24 14:44 ` Jan Beulich
2015-06-22 18:56 ` [PATCH v2 05/12] VMX/altp2m: add code to support EPTP switching and #VE Ed White
2015-06-24 11:59 ` Andrew Cooper
2015-06-24 17:31 ` Ed White
2015-06-24 17:40 ` Andrew Cooper
2015-06-22 18:56 ` [PATCH v2 06/12] VMX: add VMFUNC leaf 0 (EPTP switching) to emulator Ed White
2015-06-24 12:47 ` Andrew Cooper
2015-06-24 20:29 ` Ed White
2015-06-25 8:26 ` Jan Beulich
2015-06-24 14:26 ` Jan Beulich
2015-06-22 18:56 ` [PATCH v2 07/12] x86/altp2m: add control of suppress_ve Ed White
2015-06-24 13:05 ` Andrew Cooper
2015-06-24 14:38 ` Jan Beulich
2015-06-24 17:53 ` Ed White
2015-06-25 8:12 ` Jan Beulich
2015-06-25 16:36 ` Ed White
2015-06-26 6:04 ` Jan Beulich
2015-06-26 16:27 ` Ed White
2015-07-06 17:12 ` George Dunlap
2015-07-06 17:35 ` Ed White
2015-07-06 18:29 ` George Dunlap
2015-07-06 18:43 ` Ed White
2015-07-07 10:10 ` George Dunlap
2015-07-07 16:24 ` Ed White
2015-07-07 17:33 ` George Dunlap
2015-07-07 17:38 ` Sahita, Ravi
2015-07-08 7:24 ` Jan Beulich
2015-07-08 10:12 ` Tim Deegan
2015-07-08 12:51 ` George Dunlap
2015-07-08 7:23 ` Jan Beulich
2015-07-07 8:04 ` Jan Beulich
2015-06-22 18:56 ` [PATCH v2 08/12] x86/altp2m: alternate p2m memory events Ed White
2015-06-24 13:09 ` Andrew Cooper
2015-06-24 16:01 ` Lengyel, Tamas
2015-06-24 18:02 ` Ed White
2015-06-22 18:56 ` [PATCH v2 09/12] x86/altp2m: add remaining support routines Ed White
2015-06-23 18:15 ` Lengyel, Tamas
2015-06-23 18:52 ` Ed White
2015-06-23 19:35 ` Lengyel, Tamas
2015-06-24 13:46 ` Andrew Cooper
2015-06-24 17:47 ` Ed White
2015-06-24 18:19 ` Andrew Cooper
2015-06-26 16:30 ` Ed White
2015-06-29 13:03 ` Andrew Cooper
2015-06-29 16:24 ` Ed White
2015-06-24 16:15 ` Lengyel, Tamas
2015-06-24 18:06 ` Ed White
2015-06-25 8:52 ` Ian Campbell
2015-06-25 16:27 ` Ed White
2015-06-25 12:44 ` Lengyel, Tamas
2015-06-25 13:40 ` Razvan Cojocaru
2015-06-25 16:48 ` Ed White
2015-06-25 17:39 ` Sahita, Ravi
2015-06-25 18:22 ` Razvan Cojocaru
2015-06-25 18:23 ` Lengyel, Tamas
2015-06-25 20:46 ` Ed White
2015-06-25 22:45 ` Lengyel, Tamas
2015-06-25 23:10 ` Ed White
2015-06-25 2:44 ` Lengyel, Tamas
2015-06-25 16:31 ` Ed White
2015-06-25 17:42 ` Lengyel, Tamas
2015-06-25 20:27 ` Ed White
2015-06-25 21:33 ` Lengyel, Tamas
2015-06-22 18:56 ` [PATCH v2 10/12] x86/altp2m: define and implement alternate p2m HVMOP types Ed White
2015-06-24 13:58 ` Andrew Cooper
2015-06-24 14:53 ` Jan Beulich
2015-06-22 18:56 ` [PATCH v2 11/12] x86/altp2m: Add altp2mhvm HVM domain parameter Ed White
2015-06-24 14:06 ` Andrew Cooper
2015-06-24 14:59 ` Jan Beulich
2015-06-24 17:57 ` Ed White
2015-06-24 18:08 ` Andrew Cooper
2015-06-25 8:34 ` Jan Beulich
2015-06-25 8:33 ` Jan Beulich
2015-06-22 18:56 ` [PATCH v2 12/12] x86/altp2m: XSM hooks for altp2m HVM ops Ed White
2015-06-26 19:24 ` Daniel De Graaf
2015-06-26 19:35 ` Ed White
2015-06-29 17:52 ` Daniel De Graaf
2015-06-29 17:55 ` Sahita, Ravi
2015-06-23 21:27 ` [PATCH v2 00/12] Alternate p2m: support multiple copies of host p2m Lengyel, Tamas
2015-06-23 22:25 ` Ed White
2015-06-24 5:39 ` Razvan Cojocaru
2015-06-24 13:32 ` Lengyel, Tamas
2015-06-24 13:37 ` Razvan Cojocaru
2015-06-24 16:43 ` Ed White
2015-06-24 21:34 ` Lengyel, Tamas
2015-06-24 22:02 ` Ed White
2015-06-24 22:45 ` Lengyel, Tamas
2015-06-24 22:55 ` Ed White [this message]
2015-06-25 9:00 ` Andrew Cooper
2015-06-25 16:38 ` Ed White
2015-06-25 17:29 ` Lengyel, Tamas
2015-06-25 20:34 ` Ed White
2015-06-24 14:10 ` Andrew Cooper
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=558B3563.9070402@intel.com \
--to=edmund.h.white@intel.com \
--cc=andrew.cooper3@citrix.com \
--cc=dgdegra@tycho.nsa.gov \
--cc=ian.jackson@eu.citrix.com \
--cc=jbeulich@suse.com \
--cc=ravi.sahita@intel.com \
--cc=rcojocaru@bitdefender.com \
--cc=tim@xen.org \
--cc=tlengyel@novetta.com \
--cc=wei.liu2@citrix.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).