All of lore.kernel.org
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
	"Zhanghaoyu (A)" <haoyu.zhang@huawei.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	KVM <kvm@vger.kernel.org>, Gleb Natapov <gleb@redhat.com>,
	Avi Kivity <avi@cloudius-systems.com>,
	Eric Blake <eblake@redhat.com>,
	Luonengjun <luonengjun@huawei.com>,
	"Huangweidong (C)" <weidong.huang@huawei.com>,
	"Gonglei (Arei)" <arei.gonglei@huawei.com>,
	"Gaowei (UVP)" <gao.gaowei@huawei.com>,
	"chenliang (T)" <chenliang88@huawei.com>
Subject: Re: hotplug: VM got stuck when attaching a pass-through device to the non-pass-through VM for the first time
Date: Tue, 18 Feb 2014 11:42:19 +0100	[thread overview]
Message-ID: <5303390B.50903@redhat.com> (raw)
In-Reply-To: <20140218103828.GB8114@redhat.com>

Il 18/02/2014 11:38, Michael S. Tsirkin ha scritto:
> What if you detach and re-attach?
> Is it fast then?
> If yes this means the issue is COW breaking that occurs
> with get_user_pages, not translation as such.
> Try hugepages with prealloc - does it help?

I agree it's either COW breaking or (similarly) locking pages that the 
guest hasn't touched yet.

You can use prealloc or "-rt mlock=on" to avoid this problem.

Paolo

WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
	"Zhanghaoyu (A)" <haoyu.zhang@huawei.com>
Cc: "chenliang (T)" <chenliang88@huawei.com>,
	Avi Kivity <avi@cloudius-systems.com>,
	"Huangweidong (C)" <weidong.huang@huawei.com>,
	KVM <kvm@vger.kernel.org>, Gleb Natapov <gleb@redhat.com>,
	Luonengjun <luonengjun@huawei.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	"Gonglei (Arei)" <arei.gonglei@huawei.com>,
	"Gaowei (UVP)" <gao.gaowei@huawei.com>
Subject: Re: [Qemu-devel] hotplug: VM got stuck when attaching a pass-through device to the non-pass-through VM for the first time
Date: Tue, 18 Feb 2014 11:42:19 +0100	[thread overview]
Message-ID: <5303390B.50903@redhat.com> (raw)
In-Reply-To: <20140218103828.GB8114@redhat.com>

Il 18/02/2014 11:38, Michael S. Tsirkin ha scritto:
> What if you detach and re-attach?
> Is it fast then?
> If yes this means the issue is COW breaking that occurs
> with get_user_pages, not translation as such.
> Try hugepages with prealloc - does it help?

I agree it's either COW breaking or (similarly) locking pages that the 
guest hasn't touched yet.

You can use prealloc or "-rt mlock=on" to avoid this problem.

Paolo

  reply	other threads:[~2014-02-18 10:42 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-18  2:38 hotplug: VM got stuck when attaching a pass-through device to the non-pass-through VM for the first time Zhanghaoyu (A)
2014-02-18  2:38 ` [Qemu-devel] " Zhanghaoyu (A)
2014-02-18 10:38 ` Michael S. Tsirkin
2014-02-18 10:38   ` [Qemu-devel] " Michael S. Tsirkin
2014-02-18 10:42   ` Paolo Bonzini [this message]
2014-02-18 10:42     ` Paolo Bonzini
2014-02-18 10:51     ` Michael S. Tsirkin
2014-02-18 10:51       ` [Qemu-devel] " Michael S. Tsirkin
2014-02-18 11:05       ` Paolo Bonzini
2014-02-18 11:05         ` [Qemu-devel] " Paolo Bonzini
2014-02-18 11:16         ` Michael S. Tsirkin
2014-02-18 11:16           ` [Qemu-devel] " Michael S. Tsirkin
2014-02-24 11:38         ` Zhanghaoyu (A)
2014-02-24 11:38           ` [Qemu-devel] " Zhanghaoyu (A)
2014-02-18 11:17     ` Zhanghaoyu (A)
2014-02-18 11:17       ` [Qemu-devel] " Zhanghaoyu (A)
2014-02-18 10:59   ` Zhanghaoyu (A)
2014-02-18 10:59     ` [Qemu-devel] " Zhanghaoyu (A)
  -- strict thread matches above, loose matches on Subject: below --
2014-02-18  2:03 Zhanghaoyu (A)

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=5303390B.50903@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=arei.gonglei@huawei.com \
    --cc=avi@cloudius-systems.com \
    --cc=chenliang88@huawei.com \
    --cc=eblake@redhat.com \
    --cc=gao.gaowei@huawei.com \
    --cc=gleb@redhat.com \
    --cc=haoyu.zhang@huawei.com \
    --cc=kvm@vger.kernel.org \
    --cc=luonengjun@huawei.com \
    --cc=mst@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=weidong.huang@huawei.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.