Thanks Laine for taking the time to clarify this. cheers t. On Monday 23 February 2015 16:51:26 Laine Stump wrote:

On 02/23/2015 02:26 PM, Thomas Stein wrote:

...

Hello.

I'm not able to disable the sata controller on a machine='pc-q35-2.1' type VM.> Whenever i delete: <controller type='sata' index='0'>

<address type='pci' domain='0x0000' bus='0x00' slot='0x1f'

function='0x2'/>

</controller>

it gets added again when i close the editor.

The reason i would like to delete the sata controller is this error while trying to migrate the machine:

2015-02-23 19:04:11.181+0000: 1972: error : qemuMonitorJSONCheckError:381 : internal error: unable to execute QEMU command 'migrate': State blocked by non-migratable device '0000:00:1f.2/ich9_ahci'

Someone has an idea to solve this?

Yep. You have described the situation perfectly. Here are my notes from libvirt commit c27b0bb171d9bdac10a93492a2a99eaa22746694, which fixed the handling of "default" devices in the Q35 machinetype:

sata - a q35 machine always has a sata controller implicitly added at slot 0x1F, function 2. There is no way to avoid this controller, so we always add it. Note that the xml2xml tests for the pcie-root and q35 cases were changed to use DO_TEST_DIFFERENT() so that we can check for the sata controller being automatically added. This is especially important because we can't check for it in the xml2argv output (it has no effect on that output since it's an implicit device).

So basically when you specify a q35 machinetype, you get a SATA controller at 00:1f.2 even though you have added no commandline args to ask for it. And unlike the default network device (which libvirt can eliminate by adding "-net none" to the qemu commandline), there is no way to avoid this device.

And it is also true that any machine with a SATA controller can't be migrated because of problems with the driver. I just talked to the person responsible for fixing these bugs in qemu, and he said that the patches will go upstream "soon", and that he hopes they will be in qemu 2.3. In the meantime, the only way to avoid this problem is to switch to an i440fx-based machinetype (this will require removing all the pci controllers from your config as well as removing all <address type='pci' .../> elements within all devices in the domain; libvirt will then reassign PCI addresses in the guest appropriate to the new machine type. IMPORTANT: If the guest is running MS Windows, this may require a new "activation"; best to keep a copy of the old config and an image of the disk just in case there are problems!)

On 03/11/2015 08:20 PM, Nerijus Baliunas wrote:

Laine Stump <laine@...> writes:

...

And it is also true that any machine with a SATA controller can't be migrated because of problems with the driver. I just talked to the person responsible for fixing these bugs in qemu, and he said that the patches will go upstream "soon", and that he hopes they will be in qemu 2.3. Are these patches available yet?

Here is the info straight from the author (I've also Cc'ed him to this mail): =============== The AHCI migration series is here: http://lists.gnu.org/archive/html/qemu-devel/2015-02/msg05200.html The tests in that series depend upon some other upstream tests, so the order on top of current origin/master would be something like: http://lists.gnu.org/archive/html/qemu-devel/2015-03/msg02094.html http://lists.gnu.org/archive/html/qemu-devel/2015-03/msg02151.html http://lists.gnu.org/archive/html/qemu-devel/2015-02/msg05200.html There's a minor pathing issue with how a test in the first series there locates the qemu-img binary (It uses the system's qemu-img instead of the local build copy), but otherwise that gives you all the framework for the ahci tests. These are all just tests, at any rate -- the actual patch that enables the migration is small and trivial and can be applied directly to current upstream: http://lists.gnu.org/archive/html/qemu-devel/2015-02/msg05202.html All of the requisites that make AHCI safe to migrate are already upstream now. =========== As I understand it, all except the last patch will be in qemu 2.3. Also, he is actively soliciting people to test it, so if you've been wanting to learn how to build qemu from source, now is your opportunity to figure it out!

On 03/22/2015 08:23 PM, Nerijus Baliunas wrote:

On Thu, 12 Mar 2015 14:56:08 -0400 Laine Stump <laine@laine.org> wrote:

...

Here is the info straight from the author (I've also Cc'ed him to this mail):

=============== The AHCI migration series is here:

http://lists.gnu.org/archive/html/qemu-devel/2015-02/msg05200.html

...

These are all just tests, at any rate -- the actual patch that enables the migration is small and trivial and can be applied directly to current upstream:

http://lists.gnu.org/archive/html/qemu-devel/2015-02/msg05202.html

All of the requisites that make AHCI safe to migrate are already upstream now. ===========

As I understand it, all except the last patch will be in qemu 2.3. Also, he is actively soliciting people to test it, so if you've been wanting to learn how to build qemu from source, now is your opportunity to figure it out!

Are the needed patches in 2.3.0-rc0? Is it possible to backport AHCI migration to RHEL 7.1 qemu or will it be too much work?

Regards, Nerijus

The patches that improve the stability of AHCI migration are in 2.3-rc0. We still have not /enabled/ migration upstream, but editing to code to allow it is fairly trivial -- it's just a true/false value in the code. My words of caution: (1) We still have some bugs in the AHCI device which may necessitate changing the migration format of the device. Since we have not officially enabled migration, these format changes may leave you unable to migrate to later versions, because we are not currently being careful to maintain backwards compatibility with this "unreleased" device. [If you are wondering what the probability of being unable to migrate to an official build where AHCI migration is supported is: Nearly 100%.] (2) Because we have not enabled migration of AHCI officially, [And this is not enabled or supported in RHEL!] you may run into bugs. I wouldn't do this on a production system. That said, if you do want to try it out on non-essential systems; for testing, development &c: I'd appreciate any bug reports. See http://lists.gnu.org/archive/html/qemu-devel/2015-02/msg05202.html as mentioned above for the patch that simply enables migration. --js

On 03/23/2015 08:05 PM, Nerijus Baliunas wrote:

On Mon, 23 Mar 2015 10:36:33 -0400 John Snow <jsnow@redhat.com> wrote:

...

...

Are the needed patches in 2.3.0-rc0? Is it possible to backport AHCI migration to RHEL 7.1 qemu or will it be too much work?

The patches that improve the stability of AHCI migration are in 2.3-rc0. We still have not /enabled/ migration upstream, but editing to code to allow it is fairly trivial -- it's just a true/false value in the code.

I built 2.3.0-rc0 but also added RH patches which applied (mainly for pc-q35-rhel7.1.0 machine type support) from http://ftp.redhat.com/pub/redhat/linux/enterprise/7Server/en/RHEV/SRPMS/qemu...

After suspending and restoring VM prints the following and hangs:

[root localhost ~]# [ 43.595571 irq 23: nobody cared (try booting with the "irqpoll" option) [ 43.596004] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.3-200.fc20.x86_64 #1 [ 43.596004] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) . BIOS seabios-1.7.5-8.el7 04/01/2014 [ 43.596004] 0000000000000000 be8ae26f5ae0021d ffff88007fc03d18 ffffffff81728acc [ 43.596004] ffff88007a88a800 ffff88O07fc03d40 ffffffff810ea4e2_

Any idea why? I will try with a pure qemu w/o RH patches later.

Regards, Nerijus

I do not know, sorry.