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From: Jason Wang <jasowang@redhat.com>
To: Jintack Lim <jintack@cs.columbia.edu>,
	QEMU Devel Mailing List <qemu-devel@nongnu.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] Logging dirty pages from vhost-net in-kernel with vIOMMU
Date: Wed, 5 Dec 2018 09:30:19 +0800	[thread overview]
Message-ID: <915953bd-cc9c-9456-b619-297138f68ae6@redhat.com> (raw)
In-Reply-To: <CAHyh4xgZhGnEvkD5RiUazZ9Eq_jzr4=bXHfwBvCBkbOLN2UyKA@mail.gmail.com>


On 2018/12/5 上午2:37, Jintack Lim wrote:
> Hi,
>
> I'm wondering how the current implementation works when logging dirty
> pages during migration from vhost-net (in kernel) when used vIOMMU.
>
> I understand how vhost-net logs GPAs when not using vIOMMU. But when
> we use vhost with vIOMMU, then shouldn't vhost-net need to log the
> translated address (GPA) instead of the address written in the
> descriptor (IOVA) ? The current implementation looks like vhost-net
> just logs IOVA without translation in vhost_get_vq_desc() in
> drivers/vhost/net.c. It seems like QEMU doesn't do any further
> translation of the dirty log when syncing.
>
> I might be missing something. Could somebody shed some light on this?


Good catch. It looks like a bug to me. Want to post a patch for this?

Thanks


>
> Thanks,
> Jintack
>
>

  reply	other threads:[~2018-12-05  1:30 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-04 18:37 [Qemu-devel] Logging dirty pages from vhost-net in-kernel with vIOMMU Jintack Lim
2018-12-05  1:30 ` Jason Wang [this message]
2018-12-05  1:59   ` Michael S. Tsirkin
2018-12-05  3:02     ` Jason Wang
2018-12-05 13:32       ` Michael S. Tsirkin
2018-12-06  7:27         ` Jason Wang
2018-12-05 14:47   ` Jintack Lim
2018-12-06  7:33     ` Jason Wang
2018-12-06 12:11       ` Jintack Lim
2018-12-06 12:44         ` Jason Wang
2018-12-07 12:37           ` Jason Wang
2018-12-09 18:31             ` Jintack Lim

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