ACK: [SRU][Q:linux-oracle][PATCH 0/1] oracle: set enable_virt_at_load default to false on kernels > 6.8

[Benjamin Wheeler]

Acked-by: Benjamin Wheeler <benjamin.wheeler at canonical.com>

On Thu, Jan 29, 2026 at 12:34 PM Vinicius Peixoto <
vinicius.peixoto at canonical.com> wrote:

> BugLink: https://bugs.launchpad.net/bugs/2139360
>
> [Impact]
>
> OCI uses live migration to migrate VM instances from hosts to hosts.
> That feature is currently not possible if nested virtualisation is
> enabled. However, in commit b4886fab6fb62 ("KVM: Add a module param to
> allow enabling virtualization when KVM is loaded"), the
> enable_virt_at_load parameter was introduced for the KVM module, and was
> set to true by default, making it such that the kvm module sets the
> EFER.SVME bit at load time, rather than when a guest is started. This is
> a breaking change for the OCI live migration use case.
>
> [Fix]
>
> Change the default value of enable_virt_at_load to false in our Oracle
> kernels > 6.8 in order to support the live migration use case. This is
> implemented as a sauce patch within the Oracle kernels only, since the
> justification is specific to the OCI use case and unlikely to be
> accepted by upstream.
>
> [Test plan]
>
> Oracle has validated this fix on their side using packages provided by
> Phil Cox in this PPA (thanks Phil!):
>
> https://launchpad.net/~philcox/+archive/ubuntu/oracle-sf00417471-disable-enable-virt-at-load
>
> [Where problems could occur]
>
> This change is relatively harmless, with the only downside (currently,
> on the 6.17 Oracle kernel) being that TDX requires
> enable_virt_at_load=true since fcdbdf63431c9 ("KVM: VMX: Initialize TDX
> during KVM module load"); however, this limitation is not currently
> relevant to the OCI use case.
>
> [Other info]
> SF #00417471
>
> Philip Cox (1):
>   UBUNTU: SAUCE: kvm: set `enable_virt_at_load` default to false
>
>  virt/kvm/kvm_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> --
> 2.51.0
>
>
> --
> kernel-team mailing list
> kernel-team at lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/kernel-team
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20260130/8ed56680/attachment.html>