On 4/22/22 12:01, Marc Zyngier wrote:
These patches are against kvm/next, so that is already what I did. :)
Can you please post a complete series? It is becoming really hard to
track what you are doing.
Yes, I'll post a complete series for kvm/master in a second.
On the other hand right now the ARM and RISC-V flags are unusable with
32-bit userspace, so we need to fix _something_ in 5.18 as well.
What 32bit userspace? arm64 doesn't have any that can interact with KVM,
so I don't see anything to fix on that front.
You're right, ARM64 does not define KVM_COMPAT. But RISC-V does.
For your proposal, all that's missing is a 5.18 patch to add the
padding. But since the flags UAPI was completely unused before 5.18
and there's no reason to inflict the different naming of fields to
userspace. So I think we want to apply this UAPI change in 5.18 too.
As it was pointed out already, CrosVM has already started looking at
the flags. The fact that it was always 0 until now doesn't make it
less of a UAPI.
I heard that and that's exactly why I dropped the idea of using
NDATA_VALID in bit 31 of flags, and switched to a capability instead.
If it is desirable for Android, crosvm can "quirk" that ARM always has
valid data[0].
Paolo
I'd like to see a full series that implements the transition before we
make a decision on this.
