KVM SnowRidge Split-lock disable

[Paul Lai]

When bit 29 is set in Test Control MSR register 0x33, a #AC execption
 is generated for split locked accesses at all CPL irrespective of
 CR0.AM or EFLAGS.AC.

This feature can help developers to capture memory accesses that across cachelines with #LOCK assertion. Then developers can reconstruct their program accordingly

Upstream target linux 5.3
Target Release: 19.10

[Christian Ehrhardt  (paelzer)]

Hi,
title says KVM, but the bug is only against xen so far.

Will this need an "qemu (ubuntu)" and/or "linux (ubuntu)" task as well?

- kernel 4.20 is listed so I assume the latter.
- Comments do not yet mention Qemu

[Christian Ehrhardt  (paelzer)]

Oh mass update fail, this one actually is against kvm.
Which is the wrong package since several years actually.

Fixing that and setting qemu.
But it leaves the questions:
- need kernel changes/task as well as 4.20 is listed?
- will this be in qemu 2.13, if not can you provide a list of commits?

[quanxian (quanxian-wang)]

patches to lkml along with kernel's patches.

Here is the link:

https://lkml.org/lkml/2019/3/1/749

It's along with kernel enabling patches.

[Christian Ehrhardt  (paelzer)]

My questions in comment #1 where no answered directly yet, but this still is using only kernel patches so far, I think it is time to add at least a kernel task.

Furthermore it isn't upstream yet and the target being 5.2 is a bit out still, so I'd think you should target 19.10

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1782209

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Christian Ehrhardt  (paelzer)]

Hi,
I have not seen the kernel changes in 5.2 RCs - is there an update on their progress?
Also any updates, links, commits on the related qemu contribution?

[Paul Lai (pclai)]

Related QEMU patch can be found at:

https://lists.gnu.org/archive/html/qemu-devel/2019-03/msg00507.html

and related kvm-unit-test can be found at:

https://patchwork.kernel.org/patch/10837677/