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

From: Quentin Perret
Date: Fri Feb 07 2025 - 09:54:49 EST


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(-)

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2.48.1.502.g6dc24dfdaf-goog