[PATCH v3 0/2] KVM: arm64: Assorted IPA size fixes

From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Will Deacon <will@kernel.org>, Andrew Jones <drjones@redhat.com>,
	Eric Auger <eric.auger@redhat.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	kernel-team@android.com
Subject: [PATCH v3 0/2] KVM: arm64: Assorted IPA size fixes
Date: Thu, 11 Mar 2021 10:00:14 +0000	[thread overview]
Message-ID: <20210311100016.3830038-1-maz@kernel.org> (raw)

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@kernel.org
[2] https://lore.kernel.org/r/20210310104208.3819061-1-maz@kernel.org

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