From: "Jan Beulich" <JBeulich@suse.com>
To: George Dunlap <george.dunlap@citrix.com>
Cc: Kevin Tian <kevin.tian@intel.com>,
George Dunlap <george.dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Tim Deegan <tim@xen.org>,
xen-devel@lists.xen.org, Paul Durrant <paul.durrant@citrix.com>,
Yu Zhang <yu.c.zhang@linux.intel.com>,
zhiyuan.lv@intel.com, JunNakajima <jun.nakajima@intel.com>
Subject: Re: [PATCH v4 3/3] x86/ioreq server: Add HVMOP to map guest ram with p2m_ioreq_server to an ioreq server.
Date: Wed, 22 Jun 2016 05:50:39 -0600 [thread overview]
Message-ID: <576A97AF02000078000F7A17@prv-mh.provo.novell.com> (raw)
In-Reply-To: <76e213ae-551b-7f88-0ec5-bfecdc802d79@citrix.com>
>>> On 22.06.16 at 12:15, <george.dunlap@citrix.com> wrote:
> On 22/06/16 11:10, Jan Beulich wrote:
>>>>> On 22.06.16 at 11:47, <george.dunlap@citrix.com> wrote:
>>> So you're afraid of this sequence of events?
>>> 1) Server A de-registered, triggering a ioreq_server -> ram_rw type change
>>> 2) gfn N is marked as misconfigured
>>> 3) Server B registers and marks gfn N as ioreq_server
>>> 4) When N is accessed, the misconfiguration is resolved incorrectly to
>>> ram_rw
>>>
>>> But that can't happen, because misconfigured entries are resolved before
>>> setting a p2m entry; so at step 3, gfn N will be first set to
>>> (non-misconfigured) ram_rw, then changed to (non-misconfigured)
>>> ioreq_server.
>>>
>>> Or is there another sequence of events that I'm missing?
>>
>> 1) Server A marks GFN Y as ioreq_server
>> 2) Server A de-registered, triggering a ioreq_server -> ram_rw type
>> change
>> 3) Server B registers and gfn Y still didn't become ram_rw again (as
>> the misconfiguration didn't trickle down the tree far enough)
>
> There are some missing steps here. Gfn Y is still misconfigured, right?
> What will happen when the misconfiguration is resolved? Will it not
> become ram_rw? If not, what would it change to and why?
Oh, right, of course.
Jan
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next prev parent reply other threads:[~2016-06-22 11:50 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-19 9:05 [PATCH v4 0/3] x86/ioreq server: Introduce HVMMEM_ioreq_server mem type Yu Zhang
2016-05-19 9:05 ` [PATCH v4 1/3] x86/ioreq server: Rename p2m_mmio_write_dm to p2m_ioreq_server Yu Zhang
2016-06-14 10:04 ` Jan Beulich
2016-06-14 13:14 ` George Dunlap
2016-06-15 10:51 ` Yu Zhang
2016-05-19 9:05 ` [PATCH v4 2/3] x86/ioreq server: Add new functions to get/set memory types Yu Zhang
2016-05-19 9:05 ` [PATCH v4 3/3] x86/ioreq server: Add HVMOP to map guest ram with p2m_ioreq_server to an ioreq server Yu Zhang
2016-06-14 10:45 ` Jan Beulich
2016-06-14 13:13 ` George Dunlap
2016-06-14 13:31 ` Jan Beulich
2016-06-15 9:50 ` George Dunlap
2016-06-15 10:21 ` Jan Beulich
2016-06-15 11:28 ` George Dunlap
2016-06-16 9:30 ` Yu Zhang
2016-06-16 9:55 ` Jan Beulich
2016-06-17 10:17 ` George Dunlap
2016-06-20 9:03 ` Yu Zhang
2016-06-20 10:10 ` George Dunlap
2016-06-20 10:25 ` Jan Beulich
2016-06-20 10:32 ` George Dunlap
2016-06-20 10:55 ` Jan Beulich
2016-06-20 11:28 ` Yu Zhang
2016-06-20 13:13 ` George Dunlap
2016-06-21 7:42 ` Yu Zhang
2016-06-20 10:30 ` Yu Zhang
2016-06-20 10:43 ` George Dunlap
2016-06-20 10:45 ` Jan Beulich
2016-06-20 11:06 ` Yu Zhang
2016-06-20 11:20 ` Jan Beulich
2016-06-20 12:06 ` Yu Zhang
2016-06-20 13:38 ` Jan Beulich
2016-06-21 7:45 ` Yu Zhang
2016-06-21 8:22 ` Jan Beulich
2016-06-21 9:16 ` Yu Zhang
2016-06-21 9:47 ` Jan Beulich
2016-06-21 10:00 ` Yu Zhang
2016-06-21 14:38 ` George Dunlap
2016-06-22 6:39 ` Jan Beulich
2016-06-22 8:38 ` Yu Zhang
2016-06-22 9:11 ` Jan Beulich
2016-06-22 9:16 ` George Dunlap
2016-06-22 9:29 ` Jan Beulich
2016-06-22 9:47 ` George Dunlap
2016-06-22 10:07 ` Yu Zhang
2016-06-22 11:33 ` George Dunlap
2016-06-23 7:37 ` Yu Zhang
2016-06-23 10:33 ` George Dunlap
2016-06-24 4:16 ` Yu Zhang
2016-06-24 6:12 ` Jan Beulich
2016-06-24 7:12 ` Yu Zhang
2016-06-24 8:01 ` Jan Beulich
2016-06-24 9:57 ` Yu Zhang
2016-06-24 10:27 ` Jan Beulich
2016-06-22 10:10 ` Jan Beulich
2016-06-22 10:15 ` George Dunlap
2016-06-22 11:50 ` Jan Beulich [this message]
2016-06-15 10:52 ` Yu Zhang
2016-06-15 12:26 ` Jan Beulich
2016-06-16 9:32 ` Yu Zhang
2016-06-16 10:02 ` Jan Beulich
2016-06-16 11:18 ` Yu Zhang
2016-06-16 12:43 ` Jan Beulich
2016-06-20 9:05 ` Yu Zhang
2016-06-14 13:14 ` George Dunlap
2016-05-27 7:52 ` [PATCH v4 0/3] x86/ioreq server: Introduce HVMMEM_ioreq_server mem type Zhang, Yu C
2016-05-27 10:00 ` Jan Beulich
2016-05-27 9:51 ` Zhang, Yu C
2016-05-27 10:02 ` George Dunlap
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