linux-kernel - [PATCH 0/2] Fixes for pKVM NP-guest support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250207145438.1333475-1-qperret@google.com>
Date: Fri,  7 Feb 2025 14:54:36 +0000
From: Quentin Perret <qperret@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
	Joey Gouly <joey.gouly@....com>, Suzuki K Poulose <suzuki.poulose@....com>, 
	Zenghui Yu <yuzenghui@...wei.com>, Catalin Marinas <catalin.marinas@....com>, 
	Will Deacon <will@...nel.org>
Cc: Fuad Tabba <tabba@...gle.com>, Vincent Donnefort <vdonnefort@...gle.com>, 
	linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, 
	linux-kernel@...r.kernel.org
Subject: [PATCH 0/2] Fixes for pKVM NP-guest support

Hi all,

Here are two patches to deal with a race between the handling of
permission faults and MMU notifiers with pKVM that I found by
inspection. Specifically, pKVM gets thoroughly confused when it doesn't
find a page mapped in its relax_perm path, while standard KVM deals
with that trivially thanks to the -EAGAIN special case in
user_mem_abort(). The second patch addresses the problem by simplifying
the implementation of multiple pKVM hypercalls, which also has the nice
side effect of improving locking by not taking the global host stage-2
lock as much.

Patches based on 6.14-rc1, tested in qemu on on Google Pixel 6.

Thanks!
Quentin

Quentin Perret (2):
  KVM: arm64: Improve error handling from check_host_shared_guest()
  KVM: arm64: Simplify np-guest hypercalls

 arch/arm64/kvm/hyp/nvhe/mem_protect.c | 73 +++++++++++++++------------
 1 file changed, 40 insertions(+), 33 deletions(-)

-- 
2.48.1.502.g6dc24dfdaf-goog