This is a rework of an initial patch posted a couple of days back[1]
While working on enabling KVM on "reduced IPA size" systems, I realise
we have a couple of issues, some of while do impact userspace.
The first issue is that we accept the creation of a "default IPA size"
VM (40 bits) even when the HW doesn't support it. Not good.
The second one is that we disallow a memslot to end right where the
IPA limit is. One page less and you're good, but that's not quite what
it should be.
I intend for both patches to be backported to -stable.
Thanks,
M.
* From v2 [2]:
- Fix silly printk blunder
- Added Cc-stable and Fixes tags
* From v1 [1]:
- Don't try to cap the default IPA size. If userspace uses 0 with an
expectation that it will get 40bits, we should abide by it and
return an error immediately (noticed by Andrew)
- Added a new patch to fix the exclusive nature of the IPA limit
[1] https://lore.kernel.org/r/20210308174643.761100-1-maz@xxxxxxxxxx
[2] https://lore.kernel.org/r/20210310104208.3819061-1-maz@xxxxxxxxxx
Marc Zyngier (2):
KVM: arm64: Reject VM creation when the default IPA size is
unsupported
KVM: arm64: Fix exclusive limit for IPA size
Documentation/virt/kvm/api.rst | 3 +++
arch/arm64/kvm/mmu.c | 3 +--
arch/arm64/kvm/reset.c | 12 ++++++++----
3 files changed, 12 insertions(+), 6 deletions(-)
--
2.29.2
