Re: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

newer
[opensuse-virtual] sistemad...

older
[opensuse-virtual] adding a xen...

Jim Fehlig

13 Mar 2015 13 Mar '15

02:09

Tony Su wrote:

...

User error. I posted answer in openSUSE technical help forums.

I assume you are talking about this answer: "The xen kernel is installed <only> in the HostOS (if needed). You do <not> install the xen kernel into a Guest (unless you're trying to deploy multiple layers of virtualization which is highly inadvisable). A "normal" kernel you'd normally install in a non-virtual environment should be used in your Guest, ie desktop, default, vanilla, etc." But that is not true. kernel-xen is most certainly used in a PV guest. And in my case, the latest 13.2 kernel-xen works fine, but the latest from the Kernel:stable project does not. Regards, Jim -- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Show replies by date

Tony Su

13 Mar 13 Mar

15:21

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

Surprising (to me). Do you know what modifications in kernel-xen would be useful in a DomU? After your post, Googled the following which didn't turn up much useful for DomU (returned some hits for Dom0 likely because there were nothing more for DomU). There may be issues with certain kernels, but I haven't found a technical article yet that would suggest that kernel-xen should be a choice for DomU (although it may also be that there may not be much harm). If there is no advantage, I wonder if it should be recommended. xen "which kernel" DomU BTW - Searching the hits, although the following article discusses the Spice protocol it also contained a more general "Known Problem" requiring pci=nompci problem when booting kernel-xen in a DomU http://wiki.xen.org/wiki/SPICE_support_in_Xen Tony On Thu, Mar 12, 2015 at 7:09 PM, Jim Fehlig wrote:

...

Tony Su wrote:

...
User error. I posted answer in openSUSE technical help forums.

I assume you are talking about this answer:

"The xen kernel is installed <only> in the HostOS (if needed). You do <not> install the xen kernel into a Guest (unless you're trying to deploy multiple layers of virtualization which is highly inadvisable). A "normal" kernel you'd normally install in a non-virtual environment should be used in your Guest, ie desktop, default, vanilla, etc."

But that is not true. kernel-xen is most certainly used in a PV guest. And in my case, the latest 13.2 kernel-xen works fine, but the latest from the Kernel:stable project does not.

Regards, Jim

-- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Tony Su

15:45

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

Additional information selecting kernels for use in Xen (Dom0 or DomU) http://wiki.xen.org/wiki/Xen_Kernel_Feature_Matrix Unless I am misunderstanding the information on this official source - All modern implementations of Xen features for DomU is now implemented through the pvops framework. - The pvops framework is part of the mainline Linux kernel. This suggests that a special kernel-xen is not needed for DomU and supports all current documented features. So, maybe kernel-xen used for DomU would be just another choice to avoid possible issues in another kernel choice but not necessarily recommended? (Am open to correction, thx) Tony On Fri, Mar 13, 2015 at 8:21 AM, Tony Su wrote:

...

Surprising (to me). Do you know what modifications in kernel-xen would be useful in a DomU?

After your post, Googled the following which didn't turn up much useful for DomU (returned some hits for Dom0 likely because there were nothing more for DomU). There may be issues with certain kernels, but I haven't found a technical article yet that would suggest that kernel-xen should be a choice for DomU (although it may also be that there may not be much harm). If there is no advantage, I wonder if it should be recommended.

xen "which kernel" DomU

BTW - Searching the hits, although the following article discusses the Spice protocol it also contained a more general "Known Problem" requiring pci=nompci problem when booting kernel-xen in a DomU http://wiki.xen.org/wiki/SPICE_support_in_Xen

Tony

On Thu, Mar 12, 2015 at 7:09 PM, Jim Fehlig wrote:

...
Tony Su wrote:

...
User error. I posted answer in openSUSE technical help forums.

I assume you are talking about this answer:

"The xen kernel is installed <only> in the HostOS (if needed). You do <not> install the xen kernel into a Guest (unless you're trying to deploy multiple layers of virtualization which is highly inadvisable). A "normal" kernel you'd normally install in a non-virtual environment should be used in your Guest, ie desktop, default, vanilla, etc."

But that is not true. kernel-xen is most certainly used in a PV guest. And in my case, the latest 13.2 kernel-xen works fine, but the latest from the Kernel:stable project does not.

Regards, Jim

-- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Charles Arnold

16:06

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

...

...
...
On 3/13/2015 at 09:45 AM, Tony Su wrote: Additional information selecting kernels for use in Xen (Dom0 or DomU) http://wiki.xen.org/wiki/Xen_Kernel_Feature_Matrix

Unless I am misunderstanding the information on this official source - All modern implementations of Xen features for DomU is now implemented through the pvops framework. - The pvops framework is part of the mainline Linux kernel.

This suggests that a special kernel-xen is not needed for DomU and supports all current documented features. So, maybe kernel-xen used for DomU would be just another choice to avoid possible issues in another kernel choice but not necessarily recommended?

(Am open to correction, thx) Tony

Currently, all SUSE distros ship with a Xen kernel, not a pvops enabled kernel. The SUSE host will always contain a Xen kernel for booting into Xen. When installing a SUSE distro as a guest and you choose para-virtualization you will get a Xen kernel (kernel-xen) in the guest. If you install something like Fedora you will get a pvops kernel. Installing a Xen HVM SUSE guest will give you a native SUSE kernel (not pvops) in the guest. - Charles -- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Jim Fehlig

16:13

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

Tony Su wrote:

...

Additional information selecting kernels for use in Xen (Dom0 or DomU) http://wiki.xen.org/wiki/Xen_Kernel_Feature_Matrix

That is upstream documentation. Distros may be configured differently.

...

Unless I am misunderstanding the information on this official source - All modern implementations of Xen features for DomU is now implemented through the pvops framework. - The pvops framework is part of the mainline Linux kernel.

Right.

...

This suggests that a special kernel-xen is not needed for DomU and supports all current documented features.

The pvops kernel is missing features wrt to the xenified kernel. SUSE is actively working on closing the feature gap and moving to pvops, but currently we still use the xenified kernel (kernel-xen).

...

So, maybe kernel-xen used for DomU would be just another choice to avoid possible issues in another kernel choice but not necessarily recommended?

It's not only recommended, but required in a PV VM. kernel-default, which currently doesn't have pvops enabled, wont boot in a PV VM. Regards, Jim -- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Tony Su

17:08

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

Thx all, Yes, it does look then like kernel-xen is required for both Dom0 and DomU for the kernels openSUSE/SUSE currently provides. Tony On Fri, Mar 13, 2015 at 9:13 AM, Jim Fehlig wrote:

...

Tony Su wrote:

...
Additional information selecting kernels for use in Xen (Dom0 or DomU) http://wiki.xen.org/wiki/Xen_Kernel_Feature_Matrix

That is upstream documentation. Distros may be configured differently.

...
Unless I am misunderstanding the information on this official source - All modern implementations of Xen features for DomU is now implemented through the pvops framework. - The pvops framework is part of the mainline Linux kernel.

Right.

...
This suggests that a special kernel-xen is not needed for DomU and supports all current documented features.

The pvops kernel is missing features wrt to the xenified kernel. SUSE is actively working on closing the feature gap and moving to pvops, but currently we still use the xenified kernel (kernel-xen).

...
So, maybe kernel-xen used for DomU would be just another choice to avoid possible issues in another kernel choice but not necessarily recommended?

It's not only recommended, but required in a PV VM. kernel-default, which currently doesn't have pvops enabled, wont boot in a PV VM.

Regards, Jim

-- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Tony Su

18:14

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

I've posted a correction in the forementioned Tech Help Forums which describes these different Xen implementations and recommends that the User should select the DomU kernel based on first determining what kind of kernel Linode is implementing. Tony On Fri, Mar 13, 2015 at 10:08 AM, Tony Su wrote:

...

Thx all, Yes, it does look then like kernel-xen is required for both Dom0 and DomU for the kernels openSUSE/SUSE currently provides.

Tony

On Fri, Mar 13, 2015 at 9:13 AM, Jim Fehlig wrote:

...
Tony Su wrote:

...
Additional information selecting kernels for use in Xen (Dom0 or DomU) http://wiki.xen.org/wiki/Xen_Kernel_Feature_Matrix

That is upstream documentation. Distros may be configured differently.

...
Unless I am misunderstanding the information on this official source - All modern implementations of Xen features for DomU is now implemented through the pvops framework. - The pvops framework is part of the mainline Linux kernel.

Right.

...
This suggests that a special kernel-xen is not needed for DomU and supports all current documented features.

The pvops kernel is missing features wrt to the xenified kernel. SUSE is actively working on closing the feature gap and moving to pvops, but currently we still use the xenified kernel (kernel-xen).

...
So, maybe kernel-xen used for DomU would be just another choice to avoid possible issues in another kernel choice but not necessarily recommended?

It's not only recommended, but required in a PV VM. kernel-default, which currently doesn't have pvops enabled, wont boot in a PV VM.

Regards, Jim

-- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

aleph2＠vfemail.net

18:37

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

On 2015-03-13 18:14, Tony Su wrote:

...

I've posted a correction in the forementioned Tech Help Forums which describes these different Xen implementations and recommends that the User should select the DomU kernel based on first determining what kind of kernel Linode is implementing.

I'll admit I'm completely lost trying to follow what you're trying to solve. Or even if your comments, in this thread I started, are for me. So getting back to my original point, with particular respect to Linode, all Linodes are PV guests. You need a pv-ready kernel to launch the guest. Your options there are (1) launch the guest using one of Linode's provided kernels. They're all pv-ready. (2) launch the guest using pvgrub, booting to the guest's pvops 'default' kernel (3) launch the guest using pvgrub, booting to the guest's non-pvops, 'xenified' kernel For Opensuse 13.2 guests, (1) & (3) are possible from the distro. There is currently no (2) from pkgs -- you'd have to build your own kernel for that. For now. For (1) all versions of Linode's kernels up to and including 3.19.1 work great. For (2) Arch, Gentoo, Fedora, Ubuntu (so far) all work (by that I just mean that they boot annd networking works) with latest kernels I can find. For (3) versions of Opensuse's kernels <= 3.18.x work. 3.19.x is broken right now, looks like for at least networking. ------------------------------------------------- VFEmail.net - http://www.vfemail.net ONLY AT VFEmail! - Use our Metadata Mitigator to keep your email out of the NSA's hands! $24.95 ONETIME Lifetime accounts with Privacy Features! 15GB disk! No bandwidth quotas! Commercial and Bulk Mail Options! -- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Jim Fehlig

18:46

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

Tony Su wrote:

...

Thx all, Yes, it does look then like kernel-xen is required for both Dom0 and DomU for the kernels openSUSE/SUSE currently provides.

It is not required and shouldn't be used in Xen HVM domU. HVM domUs, like KVM domains, use kernel-default + pv drivers. Regards, Jim -- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

Tony Su

16 Mar 16 Mar

03:19

New subject: [opensuse-virtual] Upgrading Opensuse 13.2 kernel in a Xen Guest breaks networking and access to it. Downgrading it fixes it. What's wrong?

I don't know what Linode is running on their Host. I didn't see it mentioned earlier in this thread and admit I didn't research available documentation or email Linode to determine what is used. Are you saying that it should not matter what method the HostOS is implementing Xen, an openSUSE Xen Guest using kernel-default will already include and use pv drivers and should work? I can imagine this would be the case if implementations are not significant, the only important thing is a common interface between Xen Host and Xen Guest. But if the above statement is correct, then it deepens the mystery (possibly requires deeper inspection) why kernel-xen was required by the OP's Guest and kernel-default fails. I wrote my Forum post based on the evidence presented by the OP in the first post what worked and what didn't. Tony On Fri, Mar 13, 2015 at 11:46 AM, Jim Fehlig wrote:

...

Tony Su wrote:

...
Thx all, Yes, it does look then like kernel-xen is required for both Dom0 and DomU for the kernels openSUSE/SUSE currently provides.

It is not required and shouldn't be used in Xen HVM domU. HVM domUs, like KVM domains, use kernel-default + pv drivers.

Regards, Jim

-- To unsubscribe, e-mail: opensuse-virtual+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-virtual+owner@opensuse.org

3333

Age (days ago)

3336

Last active (days ago)

List overview

Download

9 comments

4 participants

participants (4)

aleph2＠vfemail.net
Charles Arnold
Jim Fehlig
Tony Su