Re: [PATCH 1/2] KVM: arm64: nv: Allocate the shadow S2 MMUs individually

[Karl Mehltretter <kmehltretter@gmail.com>]

On Wed, Aug 05, 2026 at 08:32:29AM +0100, Marc Zyngier wrote:
> I'd rather keep it on the VM creation path. This is VM-wide data, by
> definition, and given that its size doesn't depend on the number of
> vcpus anymore (we allocate the maximum once and for all), it is right
> where it belongs. See the untested hack below for the freeing on error.

I'll send a v2 with this soon.

> 
> > There's another issue in the current code: the ptdump debugfs file
> > keeps the raw mmu pointer as its private data. I would add that to the
> > commit message.
> 
> Why is that a problem? With this approach, the mmu pointers are always
> expected to be valid, irrespective of the allocation pattern, and we
> only publish pointers to the dumper when the S2_mmu is actively being
> used.
> 

Sorry I was talking about the old implementation. Array reallocation
leaves ptdump i_private pointers dangling.

I'm dropping the selftest for v2. It was a useful KASAN trigger, but is 
not a good fit for the current suite.

Thanks,
Karl