Re: [Qemu-devel] [PATCH] ide: Add resize callback to ide/core

From: Stefan Hajnoczi <stefanha@redhat.com>
To: John Snow <jsnow@redhat.com>
Cc: kwolf@redhat.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] ide: Add resize callback to ide/core
Date: Wed, 13 Aug 2014 15:49:49 +0100	[thread overview]
Message-ID: <20140813144949.GC27053@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <1407869049-29178-1-git-send-email-jsnow@redhat.com>

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On Tue, Aug 12, 2014 at 02:44:09PM -0400, John Snow wrote:
> Currently, if the block device backing the IDE drive is resized,
> the information about the device as cached inside of the IDEState
> structure is not updated, thus when a guest OS re-queries the drive,
> it is unable to see the expanded size.
> 
> This patch adds a resize callback to correct this, and marks the
> identify buffer cache as being dirty to force ide_identify to
> regenerate this information. This callback also attempts to update
> the legacy CHS values, if only to maintain a sense of
> informational consistency.
> 
> Lastly, a Linux guest as-is cannot resize a libata drive while in-use,
> but it can see the expanded size as part of a bus rescan event.
> This patch also allows guests such as Linux to see the new drive size
> after a soft reboot event, without having to exit the QEMU process.
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  hw/ide/core.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)

Dropped due to comments from Markus Armbruster.  I'll wait until the
discussion is finished before merging it.

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