From: Anthony Liguori <anthony@codemonkey.ws>
To: Sasha Levin <levinsasha928@gmail.com>,
Wen Congyang <wency@cn.fujitsu.com>
Cc: Gleb Natapov <gleb@redhat.com>, kvm list <kvm@vger.kernel.org>,
Jan Kiszka <jan.kiszka@siemens.com>,
qemu-devel <qemu-devel@nongnu.org>,
"linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Avi Kivity <avi@redhat.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Subject: Re: [Qemu-devel] [PATCH v7.5] kvm: notify host when the guest is panicked
Date: Sun, 22 Jul 2012 14:14:12 -0500 [thread overview]
Message-ID: <87wr1vwquz.fsf@codemonkey.ws> (raw)
In-Reply-To: <500BE68D.90005@gmail.com>
Sasha Levin <levinsasha928@gmail.com> writes:
> On 07/21/2012 10:44 AM, Wen Congyang wrote:
>> We can know the guest is panicked when the guest runs on xen.
>> But we do not have such feature on kvm.
>>
>> Another purpose of this feature is: management app(for example:
>> libvirt) can do auto dump when the guest is panicked. If management
>> app does not do auto dump, the guest's user can do dump by hand if
>> he sees the guest is panicked.
>>
>> We have three solutions to implement this feature:
>> 1. use vmcall
>> 2. use I/O port
>> 3. use virtio-serial.
>>
>> We have decided to avoid touching hypervisor. The reason why I choose
>> choose the I/O port is:
>> 1. it is easier to implememt
>> 2. it does not depend any virtual device
>> 3. it can work when starting the kernel
>
> Was the option of implementing a virtio-watchdog driver considered?
>
> You're basically re-implementing a watchdog, a guest-host interface and a set of protocols for guest-host communications.
>
> Why can't we re-use everything we have now, push a virtio watchdog
> driver into drivers/watchdog/, and gain a more complete solution to
> detecting hangs inside the guest.
The purpose of virtio is not to reinvent every possible type of device.
There are plenty of hardware watchdogs that are very suitable to be used
for this purpose. QEMU implements quite a few already.
Watchdogs are not performance sensitive so there's no point in using
virtio.
Regards,
Anthony Liguori
next prev parent reply other threads:[~2012-07-22 19:14 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-21 7:12 [PATCH v7] kvm: notify host when the guest is panicked Wen Congyang
2012-07-21 7:14 ` [PATCH 1/6 v7] start vm after reseting it Wen Congyang
2012-07-21 7:14 ` [PATCH 2/6 v7] kvm: Update kernel headers Wen Congyang
2012-07-21 7:15 ` [PATCH 3/6 v7] add a new runstate: RUN_STATE_GUEST_PANICKED Wen Congyang
2012-07-21 7:16 ` [PATCH 4/6 v7] add a new qevent: QEVENT_GUEST_PANICKED Wen Congyang
2012-07-21 7:16 ` [PATCH 5/6 v7] introduce a new qom device to deal with panicked event Wen Congyang
2012-07-21 7:19 ` [PATCH 6/6 v7] allow the user to disable pv event support Wen Congyang
2012-07-21 7:19 ` [PATCH v7] kvm: notify host when the guest is panicked Jan Kiszka
2012-07-21 8:41 ` Wen Congyang
2012-07-21 8:44 ` [PATCH v7.5] " Wen Congyang
2012-07-22 11:39 ` [Qemu-devel] " Sasha Levin
2012-07-22 19:14 ` Anthony Liguori [this message]
2012-07-22 20:03 ` Sasha Levin
2012-07-22 22:36 ` Anthony Liguori
2012-07-22 23:50 ` Sasha Levin
2012-07-23 2:08 ` Wen Congyang
2012-07-23 2:07 ` Wen Congyang
2012-07-21 10:50 ` [Qemu-devel] [PATCH v7] " Sasha Levin
2012-07-22 19:22 ` Anthony Liguori
2012-07-22 20:19 ` Sasha Levin
2012-07-22 20:31 ` Sasha Levin
2012-07-22 22:29 ` Anthony Liguori
2012-07-22 23:35 ` Sasha Levin
2012-07-22 22:20 ` Anthony Liguori
2012-07-23 6:27 ` Wen Congyang
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