From: "Pavel Dovgalyuk" <dovgaluk@ispras.ru>
To: "'Kevin Wolf'" <kwolf@redhat.com>
Cc: peter.maydell@linaro.org, pavel.dovgaluk@ispras.ru,
quintela@redhat.com, ciro.santilli@gmail.com,
jasowang@redhat.com, crosthwaite.peter@gmail.com,
qemu-devel@nongnu.org, armbru@redhat.com, alex.bennee@linaro.org,
maria.klimushenkova@ispras.ru, mst@redhat.com, kraxel@redhat.com,
boost.lists@gmail.com, thomas.dullien@googlemail.com,
pbonzini@redhat.com, mreitz@redhat.com,
artem.k.pisarenko@gmail.com, dgilbert@redhat.com,
rth@twiddle.net
Subject: RE: [for-4.2 PATCH 3/6] replay: update docs for record/replay with block devices
Date: Wed, 25 Sep 2019 12:02:46 +0300 [thread overview]
Message-ID: <001601d57380$002b3f20$0081bd60$@ru> (raw)
In-Reply-To: <20190920100150.GD5458@localhost.localdomain>
> From: Kevin Wolf [mailto:kwolf@redhat.com]
> Am 20.09.2019 um 09:25 hat Pavel Dovgalyuk geschrieben:
> > > From: Kevin Wolf [mailto:kwolf@redhat.com]
> > > Am 19.09.2019 um 14:10 hat Pavel Dovgalyuk geschrieben:
> > > > > From: Kevin Wolf [mailto:kwolf@redhat.com]
> > > > > diff --git a/block/block-backend.c b/block/block-backend.c
> > > > > index 1c605d5444..c57d3d9fdf 100644
> > > > > --- a/block/block-backend.c
> > > > > +++ b/block/block-backend.c
> > > > > @@ -17,6 +17,7 @@
> > > > > #include "block/throttle-groups.h"
> > > > > #include "hw/qdev-core.h"
> > > > > #include "sysemu/blockdev.h"
> > > > > +#include "sysemu/replay.h"
> > > > > #include "sysemu/runstate.h"
> > > > > #include "qapi/error.h"
> > > > > #include "qapi/qapi-events-block.h"
> > > > > @@ -808,6 +809,12 @@ void blk_remove_bs(BlockBackend *blk)
> > > > > int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp)
> > > > > {
> > > > > ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
> > > > > +
> > > > > + if (replay_mode != REPLAY_MODE_NONE && bs->drv != &bdrv_blkreplay) {
> > > > > + error_setg(errp, "Root node must be blkreplay");
> > > > > + return -ENOTSUP;
> > > > > + }
> > > >
> > > > I guess this is opposite direction - bs->drv is bdrv_file.
> > > > And we should check its parent.
> > >
> > > If bs->drv is bdrv_file, you want this to fail because only
> > > bdrv_blkreplay should be able to be attached to devices.
> >
> > There was a regular rr invocation (as described in docs).
> > And bs->drv always was a pointer to bdrv_file: for original image,
> > and for temporary snapshot.
>
> Hm, what was the actual command line you used? I can see that you have a
> separate -drive for the qcow2 file, so I can see how you get an unused
> BlockBackend for the qcow2 node, but I don't see how it would be a file
> node.
>
> Anyway, this leaves us two options: Either change the recommended
> command line to use -blockdev for the qcow2 file so that no BlockBackend
> is created for it (I think this might be preferable), or restrict the
> error to when the BlockBackend is used.
I started playing with -blockdev: added new blockdev for blkreplay and
constructed the following command line:
-blockdev driver=file,filename=disk.img,node-name=hd0
-blockdev driver=blkreplay,file=hd0,node-name=hd0-rr
-device virtio-blk-device,drive=hd0-rr
However, I get an error: "Could not open 'disk.img': Permission denied"
Everything works when I use this file in '-drive' parameter.
What am I doing wrong?
Pavel Dovgalyuk
next prev parent reply other threads:[~2019-09-25 9:05 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-17 11:57 [Qemu-devel] [for-4.2 PATCH 0/6] Block-related record/replay fixes Pavel Dovgalyuk
2019-09-17 11:57 ` [Qemu-devel] [for-4.2 PATCH 1/6] block: implement bdrv_snapshot_goto for blkreplay Pavel Dovgalyuk
2019-09-17 11:57 ` [Qemu-devel] [for-4.2 PATCH 2/6] replay: disable default snapshot for record/replay Pavel Dovgalyuk
2019-09-17 11:58 ` [Qemu-devel] [for-4.2 PATCH 3/6] replay: update docs for record/replay with block devices Pavel Dovgalyuk
2019-09-18 9:18 ` Kevin Wolf
2019-09-18 9:22 ` Pavel Dovgalyuk
2019-09-18 9:33 ` Kevin Wolf
2019-09-18 9:37 ` Pavel Dovgalyuk
2019-09-18 9:44 ` Kevin Wolf
2019-09-18 9:52 ` Pavel Dovgalyuk
2019-09-19 8:53 ` Kevin Wolf
2019-09-19 9:05 ` Pavel Dovgalyuk
2019-09-19 11:27 ` Kevin Wolf
2019-09-19 12:10 ` Pavel Dovgalyuk
2019-09-19 13:00 ` Kevin Wolf
2019-09-20 7:25 ` Pavel Dovgalyuk
2019-09-20 10:01 ` Kevin Wolf
2019-09-23 6:15 ` Pavel Dovgalyuk
2019-09-25 9:02 ` Pavel Dovgalyuk [this message]
2019-10-01 8:22 ` Pavel Dovgalyuk
2019-10-10 15:28 ` Kevin Wolf
2019-10-11 6:10 ` Pavel Dovgalyuk
2019-10-11 9:12 ` Kevin Wolf
2019-10-18 12:06 ` Pavel Dovgalyuk
2019-10-18 14:16 ` Kevin Wolf
2019-09-17 11:58 ` [Qemu-devel] [for-4.2 PATCH 4/6] replay: don't drain/flush bdrv queue while RR is working Pavel Dovgalyuk
2019-09-17 11:58 ` [Qemu-devel] [for-4.2 PATCH 5/6] replay: finish record/replay before closing the disks Pavel Dovgalyuk
2019-09-17 11:58 ` [Qemu-devel] [for-4.2 PATCH 6/6] replay: add BH oneshot event for block layer Pavel Dovgalyuk
2019-09-17 18:09 ` [Qemu-devel] [for-4.2 PATCH 0/6] Block-related record/replay fixes no-reply
2019-09-17 18:10 ` no-reply
2019-09-17 19:01 ` Alex Bennée
2019-09-18 8:26 ` Pavel Dovgalyuk
2019-09-18 10:42 ` Alex Bennée
2019-09-18 11:32 ` Pavel Dovgalyuk
2019-10-11 9:17 ` Kevin Wolf
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