SRU request submitted for Artful and Bionic:
https://lists.ubuntu.com/archives/kernel-team/2018-January/089404.html
** Description changed:
+ == SRU Justification ==
+ The following mainline commit introduced a regression in v4.12-rc1:
+ 2c82878b0cb3 ("KVM: VMX: require virtual NMI support")
+
+ This regression caused the kvm-intel module fail to load with the following
error:
+ "modprobe: ERROR: could not insert 'kvm_intel': Input/output error"
+
+ This error would happen because suppor for CPUs without virtual NMI was
removed
+ by commit 2c82878b0cb3.
+
+ Mainline commit 8a1b43922d0d fixes this regression and was added to
+ mainline in v4.15-rc1.
+
+
+ == Fix ==
+ commit 8a1b43922d0d1279e7936ba85c4c2a870403c95f
+ Author: Paolo Bonzini <pbonz...@redhat.com>
+ Date: Mon Nov 6 13:31:12 2017 +0100
+
+ kvm: vmx: Reinstate support for CPUs without virtual NMI
+
+ == Regression Potential ==
+ Low. This patch fixes a current regression. It was cc'd to upstream stable
+ so had additional upstream review.
+
+
+ ## Original Bug Description ##
Since upgrading from zesty to artful, I'm not longer able to use KVM on my
server:
# modprobe kvm-intel
modprobe: ERROR: could not insert 'kvm_intel': Input/output error
Searching tells me this is caused by requiring Virtual NMI support[1]
Running the script provided on the mailing list[1] to check virtualization
features confirms my CPU (Xeon E5345) doesn't support Virtual NMIs:
# python features.py | grep NMI
- NMI exiting yes
- Virtual NMIs no
- NMI-window exiting no
+ NMI exiting yes
+ Virtual NMIs no
+ NMI-window exiting no
Virtual NMI support was required in v4.12[1] and later reverted in
v4.14.3[2] as some models (including Xeons) don't support it, even if
others with the same core do.
-
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1490803
[2] https://lkml.org/lkml/2017/8/7/231
[3]
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/arch/x86/kvm/vmx.c?h=linux-4.13.y&id=2c82878b0cb38fd516fd612c67852a6bbf282003
[4]
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/arch/x86/kvm/vmx.c?h=linux-4.14.y&id=a77360e989f3dc06e4f177a0837d533d13a20d91
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1741655
Title:
Regression: KVM no longer supports Intel CPUs without Virtual NMI
Status in linux package in Ubuntu:
In Progress
Status in linux source package in Artful:
In Progress
Status in linux source package in Bionic:
In Progress
Bug description:
== SRU Justification ==
The following mainline commit introduced a regression in v4.12-rc1:
2c82878b0cb3 ("KVM: VMX: require virtual NMI support")
This regression caused the kvm-intel module fail to load with the following
error:
"modprobe: ERROR: could not insert 'kvm_intel': Input/output error"
This error would happen because suppor for CPUs without virtual NMI was
removed
by commit 2c82878b0cb3.
Mainline commit 8a1b43922d0d fixes this regression and was added to
mainline in v4.15-rc1.
== Fix ==
commit 8a1b43922d0d1279e7936ba85c4c2a870403c95f
Author: Paolo Bonzini <pbonz...@redhat.com>
Date: Mon Nov 6 13:31:12 2017 +0100
kvm: vmx: Reinstate support for CPUs without virtual NMI
== Regression Potential ==
Low. This patch fixes a current regression. It was cc'd to upstream stable
so had additional upstream review.
## Original Bug Description ##
Since upgrading from zesty to artful, I'm not longer able to use KVM on my
server:
# modprobe kvm-intel
modprobe: ERROR: could not insert 'kvm_intel': Input/output error
Searching tells me this is caused by requiring Virtual NMI support[1]
Running the script provided on the mailing list[1] to check virtualization
features confirms my CPU (Xeon E5345) doesn't support Virtual NMIs:
# python features.py | grep NMI
NMI exiting yes
Virtual NMIs no
NMI-window exiting no
Virtual NMI support was required in v4.12[1] and later reverted in
v4.14.3[2] as some models (including Xeons) don't support it, even if
others with the same core do.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1490803
[2] https://lkml.org/lkml/2017/8/7/231
[3]
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/arch/x86/kvm/vmx.c?h=linux-4.13.y&id=2c82878b0cb38fd516fd612c67852a6bbf282003
[4]
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/arch/x86/kvm/vmx.c?h=linux-4.14.y&id=a77360e989f3dc06e4f177a0837d533d13a20d91
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1741655/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
