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From: Avi Kivity <avi@redhat.com>
To: liu ping fan <qemulist@gmail.com>
Cc: Liu Ping Fan <pingfank@linux.vnet.ibm.com>,
	Stefan Hajnoczi <stefanha@gmail.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	qemu-devel@nongnu.org, Anthony Liguori <anthony@codemonkey.ws>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [Qemu-devel] [patch v4 13/16] e1000: add busy flag to anti broken device state
Date: Tue, 23 Oct 2012 11:06:09 +0200	[thread overview]
Message-ID: <50865E01.20905@redhat.com> (raw)
In-Reply-To: <CAJnKYQnVd4V1G1yC3we3RXfQSk=gtLJ+qpYXmT=CZ_neVSj9+g@mail.gmail.com>

On 10/23/2012 07:52 AM, liu ping fan wrote:
> On Mon, Oct 22, 2012 at 6:40 PM, Avi Kivity <avi@redhat.com> wrote:
>> On 10/22/2012 11:23 AM, Liu Ping Fan wrote:
>>> The broken device state is caused by releasing local lock before acquiring
>>> big lock. To fix this issue, we have two choice:
>>>   1.use busy flag to protect the state
>>>     The drawback is that we will introduce independent busy flag for each
>>>     independent device's logic unit.
>>>   2.reload the device's state
>>>     The drawback is if the call chain is too deep, the action to reload will
>>>     touch each layer. Also the reloading means to recaculate the intermediate
>>>     result based on device's regs.
>>>
>>> This patch adopt the solution 1 to fix the issue.
>>
>> Doesn't the nested mmio patch detect this?
>>
> It will only record and fix the issue on one thread. But guest can
> touch the emulated device on muti-threads.

I forgot about that.

I propose that we merge without a fix.  Upstream is broken in the same
way; it won't deadlock but it will surely break in some other way if a
write can cause another write to be triggered to the same location.

When we gain more experience with fine-graining devices we can converge
on a good solution.

-- 
error compiling committee.c: too many arguments to function

  reply	other threads:[~2012-10-23  9:06 UTC|newest]

Thread overview: 102+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-22  9:23 [Qemu-devel] [patch v4 00/16] push mmio dispatch out of big lock Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 01/16] atomic: introduce atomic operations Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 02/16] qom: apply atomic on object's refcount Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 03/16] hotplug: introduce qdev_unplug_complete() to remove device from views Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 04/16] pci: remove pci device from mem view when unplug Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 05/16] memory: introduce ref, unref interface for MemoryRegionOps Liu Ping Fan
2012-10-22  9:38   ` Avi Kivity
2012-10-23 11:51     ` Paolo Bonzini
2012-10-23 11:55       ` Avi Kivity
2012-10-23 11:57         ` Paolo Bonzini
2012-10-23 12:02           ` Avi Kivity
2012-10-23 12:06             ` Paolo Bonzini
2012-10-23 12:15               ` Avi Kivity
2012-10-23 12:32                 ` Paolo Bonzini
2012-10-23 14:49                   ` Avi Kivity
2012-10-23 15:26                     ` Paolo Bonzini
2012-10-23 16:09                       ` Avi Kivity
2012-10-24  7:29                         ` Paolo Bonzini
2012-10-25 16:28                           ` Avi Kivity
2012-10-26 15:05                             ` Paolo Bonzini
2012-10-23 12:04         ` Jan Kiszka
2012-10-23 12:12           ` Paolo Bonzini
2012-10-23 12:16             ` Jan Kiszka
2012-10-23 12:28               ` Avi Kivity
2012-10-23 12:40                 ` Jan Kiszka
2012-10-23 14:37                   ` Avi Kivity
2012-10-22  9:23 ` [Qemu-devel] [patch v4 06/16] memory: document ref, unref interface Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 07/16] memory: make mmio dispatch able to be out of biglock Liu Ping Fan
2012-10-23 12:12   ` Jan Kiszka
2012-10-23 12:36     ` Avi Kivity
2012-10-24  6:31       ` liu ping fan
2012-10-24  6:56         ` liu ping fan
2012-10-25  8:57           ` Avi Kivity
2012-10-22  9:23 ` [Qemu-devel] [patch v4 08/16] QemuThread: make QemuThread as tls to store extra info Liu Ping Fan
2012-10-22  9:30   ` Jan Kiszka
2012-10-22 17:13     ` Peter Maydell
2012-10-23  5:58       ` liu ping fan
2012-10-23 11:48       ` Paolo Bonzini
2012-10-23 11:50         ` Peter Maydell
2012-10-23 11:51           ` Jan Kiszka
2012-10-23 12:00           ` Paolo Bonzini
2012-10-23 12:27             ` Peter Maydell
2012-11-18 10:02             ` Brad Smith
2012-11-18 16:14               ` Paolo Bonzini
2012-11-18 16:15                 ` Paolo Bonzini
2012-10-22  9:23 ` [Qemu-devel] [patch v4 09/16] memory: introduce mmio request pending to anti nested DMA Liu Ping Fan
2012-10-22 10:28   ` Avi Kivity
2012-10-23 12:38   ` Gleb Natapov
2012-10-24  6:31     ` liu ping fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 10/16] memory: introduce lock ops for MemoryRegionOps Liu Ping Fan
2012-10-22 10:30   ` Avi Kivity
2012-10-23  5:53     ` liu ping fan
2012-10-23  8:53       ` Jan Kiszka
2012-10-22  9:23 ` [Qemu-devel] [patch v4 11/16] vcpu: push mmio dispatcher out of big lock Liu Ping Fan
2012-10-22 10:31   ` Avi Kivity
2012-10-22 10:36     ` Jan Kiszka
2012-10-22  9:23 ` [Qemu-devel] [patch v4 12/16] e1000: apply fine lock on e1000 Liu Ping Fan
2012-10-22 10:37   ` Avi Kivity
2012-10-23  9:04   ` Jan Kiszka
2012-10-24  6:31     ` liu ping fan
2012-10-24  7:17       ` Jan Kiszka
2012-10-25  9:01         ` Avi Kivity
2012-10-25  9:31           ` Jan Kiszka
2012-10-25 16:21             ` Avi Kivity
2012-10-25 16:39               ` Jan Kiszka
2012-10-25 17:02                 ` Avi Kivity
2012-10-25 18:48                   ` Jan Kiszka
2012-10-29  5:24                     ` liu ping fan
2012-10-24  7:29     ` liu ping fan
2012-10-25 13:34       ` Jan Kiszka
2012-10-25 16:23         ` Avi Kivity
2012-10-25 16:41           ` Jan Kiszka
2012-10-25 17:03             ` Avi Kivity
2012-10-29  5:24         ` liu ping fan
2012-10-31  7:03           ` Jan Kiszka
2012-10-22  9:23 ` [Qemu-devel] [patch v4 13/16] e1000: add busy flag to anti broken device state Liu Ping Fan
2012-10-22 10:40   ` Avi Kivity
2012-10-23  5:52     ` liu ping fan
2012-10-23  9:06       ` Avi Kivity [this message]
2012-10-23  9:07       ` Jan Kiszka
2012-10-23  9:32         ` liu ping fan
2012-10-23  9:37           ` Avi Kivity
2012-10-24  6:36             ` liu ping fan
2012-10-25  8:55               ` Avi Kivity
2012-10-25  9:00             ` Peter Maydell
2012-10-25  9:04               ` Avi Kivity
2012-10-26  3:05                 ` liu ping fan
2012-10-26  3:08                   ` liu ping fan
2012-10-26 10:25                     ` Jan Kiszka
2012-10-29  5:24                       ` liu ping fan
2012-10-29  7:50                         ` Peter Maydell
2012-10-22  9:23 ` [Qemu-devel] [patch v4 14/16] qdev: introduce stopping state Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 15/16] e1000: introduce unmap() to fix unplug issue Liu Ping Fan
2012-10-22  9:23 ` [Qemu-devel] [patch v4 16/16] e1000: implement MemoryRegionOps's ref&lock interface Liu Ping Fan
2012-10-25 14:04 ` [Qemu-devel] [patch v4 00/16] push mmio dispatch out of big lock Peter Maydell
2012-10-25 16:44   ` Jan Kiszka
2012-10-25 17:07   ` Avi Kivity
2012-10-25 17:13     ` Peter Maydell
2012-10-25 18:13       ` Marcelo Tosatti
2012-10-25 19:00         ` Jan Kiszka
2012-10-25 19:06           ` Peter Maydell
2012-10-29 15:24       ` Avi Kivity

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