Re: [PATCH 2/3] KVM: selftests: Introduce kvm_vm_dead_free

[Oliver Upton <oliver.upton@linux.dev>]

On Thu, Nov 07, 2024 at 12:26:45PM -0800, Sean Christopherson wrote:
> On Thu, Nov 07, 2024, Oliver Upton wrote:
> > On Thu, Nov 07, 2024 at 11:56:32AM -0800, Sean Christopherson wrote:
> > > ---
> > > From: Sean Christopherson <seanjc@google.com>
> > > Date: Thu, 7 Nov 2024 11:39:59 -0800
> > > Subject: [PATCH] KVM: selftests: Don't bother deleting memslots in KVM when
> > >  freeing VMs
> > > 
> > > When freeing a VM, don't call into KVM to manually remove each memslot,
> > > simply cleanup and free any userspace assets associated with the memory
> > > region.  KVM is ultimately responsible for ensuring kernel resources are
> > > freed when the VM is destroyed, deleting memslots one-by-one is
> > > unnecessarily slow, and unless a test is already leaking the VM fd, the
> > > VM will be destroyed when kvm_vm_release() is called.
> > > 
> > > Not deleting KVM's memslot also allows cleaning up dead VMs without having
> > > to care whether or not the to-be-freed VM is dead or alive.
> > 
> > Can you add a comment to kvm_vm_free() about why we want to avoid ioctls
> > in that helper? It'd help discourage this situation from happening again
> > in the future in the unlikely case someone wants to park an ioctl there.
> > 
> > > Reported-by: Eric Auger <eric.auger@redhat.com>
> > > Reported-by: Mark Brown <broonie@kernel.org>
> > > Signed-off-by: Sean Christopherson <seanjc@google.com>
> > 
> > I'm assuming you want to take this, happy to grab it otherwise.
> 
> You take it.  Unless my git foo is off the rails, this is needs to go into 6.12,
> along with a fix for the vGIC test.  That, and I already sent Paolo a pull request
> for rc7; I don't want to overwork myself ;-)

Fine -- I _guess_ I'll do it then :) It'll just go in the 6.13 pull
request.

https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git/commit/?h=next&id=5afe18dfa47daead88517b095b6e0ce012f031f8

-- 
Thanks,
Oliver