On 25.10.25 00:52, Demi Marie Obenour wrote:
On 10/24/25 10:51, David Hildenbrand wrote:
On 24.10.25 16:47, David Woodhouse wrote:
On Thu, 2025-10-23 at 22:06 +0200, David Hildenbrand wrote:
On 15.10.25 10:27, Kevin Brodsky wrote:
We currently set a TIF flag when scheduling out a task that is in
lazy MMU mode, in order to restore it when the task is scheduled
again.
The generic lazy_mmu layer now tracks whether a task is in lazy MMU
mode in task_struct::lazy_mmu_state. We can therefore check that
state when switching to the new task, instead of using a separate
TIF flag.
Signed-off-by: Kevin Brodsky <[email protected]>
---
Looks ok to me, but I hope we get some confirmation from x86 / xen
folks.
I know tglx has shouted at me in the past for precisely this reminder,
but you know you can test Xen guests under QEMU/KVM now and don't need
to actually run Xen? Has this been boot tested?
And after that, boot-testing sparc as well? :D
If it's easy, why not. But other people should not suffer for all the
XEN hacks we keep dragging along.
Which hacks? Serious question. Is this just for Xen PV or is HVM
also affected?
In the context of this series, XEN_LAZY_MMU.
Your question regarding PV/HVM emphasizes my point: how is a submitter
supposed to know which XEN combinations to test (and how to test them),
to not confidentially break something here.
We really need guidance+help from the XEN folks here.
--
Cheers
David / dhildenb
