The original NEWS entry for the vTPM transient VM crash was rather
vague and non-actionable.

As the bug is still actively experienced by users [1] of distros that
didn't yet ship an update to v11.0.0 and is hit by relatively common
usage improve the entry to mention situations when it happens a bit more
close and provide workarounds for users who are not able to update.

[1]: https://gitlab.com/libvirt/libvirt/-/issues/746

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
---
 NEWS.rst | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/NEWS.rst b/NEWS.rst
index 7dc6a3fa37..117287044a 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -97,10 +97,33 @@ v11.0.0 (2025-01-15)

 * **Bug fixes**

-  * qemu: tpm: do not update profile name for transient domains
+  * qemu: tpm: Fix crash on startup of transient domains with vTPM

-    Fix a possible crash when starting a transient domain which was
-    introduced in the previous release.
+    A bug was introduced in `v10.10.0 (2024-12-02)`_ when a transient VM with
+    a vTPM device is started either via ``virsh create domain.xml`` or when
+    creating VMs via ``virt-manager`` which uses transient definition for the
+    initial installation the libvirt daemon (``virtqemud`` or ``libvirtd``) can
+    crash.
+
+    Note that vTPM is auto-added in many cases by ``virt-install`` based on your
+    guest OS that is about to be installed.
+
+    The bug is fixed in this release. Following workarounds are possible if
+    upgrade is currently not available:
+
+     - make the VM persistent instead of starting it as transient::
+
+        virsh define domain.xml
+        virsh start.xml
+
+     - disable vTPM if practical in your deployment, either by dropping ``<tpm``
+       element or::
+
+        virt-install --tpm none ...
+
+    To obtain the XML ``virt-install`` would use for the above steps you can use::
+
+       virt-install --print-xml ...

   * qemu: Fix snapshot to not delete disk image with internal snapshot

-- 
2.48.1

On a Wednesday in 2025, Peter Krempa wrote:
>The original NEWS entry for the vTPM transient VM crash was rather
>vague and non-actionable.
>

Apologies for not making it more descriptive.


I'm not convinced the NEWS should contain step-by-step workarounds for
bugs that are already fixed - that already happened in the linked issue.

>As the bug is still actively experienced by users [1] of distros that
>didn't yet ship an update to v11.0.0 and is hit by relatively common
>usage improve the entry to mention situations when it happens a bit more
>close and provide workarounds for users who are not able to update.
>
>[1]: https://gitlab.com/libvirt/libvirt/-/issues/746
>
>Signed-off-by: Peter Krempa <pkrempa@redhat.com>
>---
> NEWS.rst | 29 ++++++++++++++++++++++++++---
> 1 file changed, 26 insertions(+), 3 deletions(-)
>
>diff --git a/NEWS.rst b/NEWS.rst
>index 7dc6a3fa37..117287044a 100644
>--- a/NEWS.rst
>+++ b/NEWS.rst
>@@ -97,10 +97,33 @@ v11.0.0 (2025-01-15)
>
> * **Bug fixes**
>
>-  * qemu: tpm: do not update profile name for transient domains
>+  * qemu: tpm: Fix crash on startup of transient domains with vTPM
>

The commit summary is already pushed and immutable.

Jano

>-    Fix a possible crash when starting a transient domain which was
>-    introduced in the previous release.
>+    A bug was introduced in `v10.10.0 (2024-12-02)`_ when a transient VM with
>+    a vTPM device is started either via ``virsh create domain.xml`` or when
>+    creating VMs via ``virt-manager`` which uses transient definition for the
>+    initial installation the libvirt daemon (``virtqemud`` or ``libvirtd``) can
>+    crash.
>+
>+    Note that vTPM is auto-added in many cases by ``virt-install`` based on your
>+    guest OS that is about to be installed.
>+
>+    The bug is fixed in this release. Following workarounds are possible if
>+    upgrade is currently not available:
>+
>+     - make the VM persistent instead of starting it as transient::
>+
>+        virsh define domain.xml
>+        virsh start.xml
>+
>+     - disable vTPM if practical in your deployment, either by dropping ``<tpm``
>+       element or::
>+
>+        virt-install --tpm none ...
>+
>+    To obtain the XML ``virt-install`` would use for the above steps you can use::
>+
>+       virt-install --print-xml ...
>
>   * qemu: Fix snapshot to not delete disk image with internal snapshot
>
>-- 
>2.48.1
>

On Thu, Feb 20, 2025 at 11:59:00 +0100, Ján Tomko wrote:
> On a Wednesday in 2025, Peter Krempa wrote:
> > The original NEWS entry for the vTPM transient VM crash was rather
> > vague and non-actionable.
> > 
> 
> Apologies for not making it more descriptive.
> 
> 
> I'm not convinced the NEWS should contain step-by-step workarounds for
> bugs that are already fixed - that already happened in the linked issue.

Well fair enough. I'll modify the patch to link to the issue instead.

> 
> > As the bug is still actively experienced by users [1] of distros that
> > didn't yet ship an update to v11.0.0 and is hit by relatively common
> > usage improve the entry to mention situations when it happens a bit more
> > close and provide workarounds for users who are not able to update.
> > 
> > [1]: https://gitlab.com/libvirt/libvirt/-/issues/746
> > 
> > Signed-off-by: Peter Krempa <pkrempa@redhat.com>
> > ---
> > NEWS.rst | 29 ++++++++++++++++++++++++++---
> > 1 file changed, 26 insertions(+), 3 deletions(-)
> > 
> > diff --git a/NEWS.rst b/NEWS.rst
> > index 7dc6a3fa37..117287044a 100644
> > --- a/NEWS.rst
> > +++ b/NEWS.rst
> > @@ -97,10 +97,33 @@ v11.0.0 (2025-01-15)
> > 
> > * **Bug fixes**
> > 
> > -  * qemu: tpm: do not update profile name for transient domains
> > +  * qemu: tpm: Fix crash on startup of transient domains with vTPM
> > 
> 
> The commit summary is already pushed and immutable.

A news entry does not at all have to deal with the commit summary or
whatever you wrote. The NEWS entry should describe the issue.

The commit message may make sense in technical terms but it doesn't
really suit the news entry in this case. It doesn't mention that it's a
crash. Users see a crash and that should be mentioned here.

On Thu, Feb 20, 2025 at 11:59:00AM +0100, Ján Tomko wrote:
> On a Wednesday in 2025, Peter Krempa wrote:
> > The original NEWS entry for the vTPM transient VM crash was rather
> > vague and non-actionable.
>
> Apologies for not making it more descriptive.
>
>
> I'm not convinced the NEWS should contain step-by-step workarounds for
> bugs that are already fixed - that already happened in the linked issue.

I think I agree. This is way too verbose for a NEWS entry.

If more people hitting this show up, and hopefully distros catch up
soon so it will be just a few of them at worst, we can just point
them to

  https://gitlab.com/libvirt/libvirt/-/issues/746

which now contains all the information they might need.

-- 
Andrea Bolognani / Red Hat / Virtualization