On Mon, Apr 19, 2021 at 09:54:18PM +0000, Sean Christopherson wrote:
+Paolo
On Sun, Apr 18, 2021, Sasha Levin wrote:
This is a note to let you know that I've just added the patch titled
KVM: VMX: Convert vcpu_vmx.exit_reason to a unionto the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: kvm-vmx-convert-vcpu_vmx.exit_reason-to-a-union.patch and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
I'm not sure we want this going into stable kernels, even for 5.10 and 5.11. I assume it got pulled in to resolve a conflict with commit 04c4f2ee3f68 ("KVM: VMX: Don't use vcpu->run->internal.ndata as an array index"), but that's should
Right.
be trivial to resolve since it's just a collision with surrounding code.
That's probably right too.
Maybe we'll end up with a more painful conflict in the future that would be best solved by grabbing this refactoring, but I don't think we're there yet.
This is the tricky part: when we start having these conflicts it's usually too late to refactor, no one cares, and backports just don't happen.
I'd actually point to the file shuffling (commits like a821bab2d1ee ("KVM: VMX: Move VMX specific files to a "vmx" subdirectory")) you did a few years ago in arch/x86/kvm/ as an example to why we can't wait: those changes made a lot of sense upstream, but for stable kernels it meant that patches were now trying to touch the wrong files and would often fail or do the wrong thing.
On hindsight, we probably should have moved files around in stable trees as well to match what upstream had, but at this point it's too late to go back and fix that, and we're stuck manually editing paths for the lifetime of most of the LTS trees.