On 2023-02-07 16:20, Ying-Chun Liu (PaulLiu) wrote:
Exposing set/way cache maintenance to a virtual machine is unsafe, not
least because the instructions are not permission-checked but also
because they are not broadcast between CPUs. Consequently, KVM traps
and
emulates such maintenance in the host kernel using by-VA operations and
looping over the stage-2 page-tables. However, when running under
protected KVM, these instructions are not able to be emulated and will
instead result in an exception being delivered to the guest.
Introduce CONFIG_CMO_BY_VA_ONLY so that virtual platforms can select
this option and perform by-VA cache maintenance instead of using the
set/way instructions.
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul....@linaro.org>
Signed-off-by: Marc Zyngier <m...@kernel.org>
Signed-off-by: Will Deacon <willdea...@google.com>
Cc: Tom Rini <tr...@konsulko.com>
The sign-off chain looks pretty odd. Either you are the author
of this patch, and I have nothing to do on the sign-off list,
or I'm the author and the authorship is wrong. Similar things
would apply for Will.
So which one is it?
M.
--
Jazz is not dead. It just smells funny...
