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From: Anthony PERARD <anthony.perard@citrix.com>
To: Olaf Hering <olaf@aepfle.de>
Cc: xen-devel@lists.xenproject.org, "Wei Liu" <wei.liu2@citrix.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH qemu-xen 4.10 & 4.11] xen_disk: Disable file locking for the PV disk backend
Date: Thu, 23 May 2019 10:41:48 +0100	[thread overview]
Message-ID: <20190523094148.GB2126@perard.uk.xensource.com> (raw)
In-Reply-To: <20190522195442.5bf116ff.olaf@aepfle.de>

On Wed, May 22, 2019 at 07:54:42PM +0200, Olaf Hering wrote:
> Am Wed, 22 May 2019 15:51:40 +0100
> schrieb Anthony PERARD <anthony.perard@citrix.com>:
> 
> > Can you give it a try with one of the affected qemu? (qemu-xen-4.10 or
> > qemu-xen-4.11)
> 
> Thanks for the patch. Unfortunately there is no easy way to trigger the race.
> Is the changed code path also exercised for PV domUs?

Yes! The code path is executed every time a disk is attached via the
qdisk backend. So as long as guest can access the pv disk, then it's
fine (for both HVM and PV domUs, and PVH).

Another way to make sure that the locking is disable is to attach a disk
to a second guest, qemu should not complain anymore. I've tested both
"raw" disk and "qcow2" disk but I'm not sure if other kind of disk needs
to be tested.

Thanks,

-- 
Anthony PERARD

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

WARNING: multiple messages have this Message-ID (diff)
From: Anthony PERARD <anthony.perard@citrix.com>
To: Olaf Hering <olaf@aepfle.de>
Cc: xen-devel@lists.xenproject.org, "Wei Liu" <wei.liu2@citrix.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH qemu-xen 4.10 & 4.11] xen_disk: Disable file locking for the PV disk backend
Date: Thu, 23 May 2019 10:41:48 +0100	[thread overview]
Message-ID: <20190523094148.GB2126@perard.uk.xensource.com> (raw)
Message-ID: <20190523094148.msElWC_l5ED6SjtA94X99e9mhAq3Y-fNHcRu17htMXs@z> (raw)
In-Reply-To: <20190522195442.5bf116ff.olaf@aepfle.de>

On Wed, May 22, 2019 at 07:54:42PM +0200, Olaf Hering wrote:
> Am Wed, 22 May 2019 15:51:40 +0100
> schrieb Anthony PERARD <anthony.perard@citrix.com>:
> 
> > Can you give it a try with one of the affected qemu? (qemu-xen-4.10 or
> > qemu-xen-4.11)
> 
> Thanks for the patch. Unfortunately there is no easy way to trigger the race.
> Is the changed code path also exercised for PV domUs?

Yes! The code path is executed every time a disk is attached via the
qdisk backend. So as long as guest can access the pv disk, then it's
fine (for both HVM and PV domUs, and PVH).

Another way to make sure that the locking is disable is to attach a disk
to a second guest, qemu should not complain anymore. I've tested both
"raw" disk and "qcow2" disk but I'm not sure if other kind of disk needs
to be tested.

Thanks,

-- 
Anthony PERARD

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

  reply	other threads:[~2019-05-23  9:41 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22 14:51 [PATCH qemu-xen 4.10 & 4.11] xen_disk: Disable file locking for the PV disk backend Anthony PERARD
2019-05-22 14:51 ` [Xen-devel] " Anthony PERARD
2019-05-22 14:54 ` Wei Liu
2019-05-22 14:54   ` [Xen-devel] " Wei Liu
2019-05-22 17:54 ` Olaf Hering
2019-05-22 17:54   ` [Xen-devel] " Olaf Hering
2019-05-23  9:41   ` Anthony PERARD [this message]
2019-05-23  9:41     ` Anthony PERARD
2019-06-05 10:53     ` Anthony PERARD
2019-06-14 13:23       ` Olaf Hering

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