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To: Sami Tolvanen <samitolvanen@google.com>
Subject: Re: [PATCH v4 03/17] arm64: kvm: stop treating register x18 as  caller save
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Date: Mon, 04 Nov 2019 12:13:00 +0109
From: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>, Catalin Marinas
 <catalin.marinas@arm.com>, Steven Rostedt <rostedt@goodmis.org>, Masami
 Hiramatsu <mhiramat@kernel.org>, Ard Biesheuvel <ard.biesheuvel@linaro.org>,
 Dave Martin <dave.martin@arm.com>, Kees Cook <keescook@chromium.org>, Laura
 Abbott <labbott@redhat.com>, Mark Rutland <mark.rutland@arm.com>, Nick
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 Ojeda <miguel.ojeda.sandonis@gmail.com>, Masahiro Yamada
 <yamada.masahiro@socionext.com>, <clang-built-linux@googlegroups.com>,
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Hi Sami,

On 2019-11-01 23:20, Sami Tolvanen wrote:
> From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>
> In preparation of reserving x18, stop treating it as caller save in
> the KVM guest entry/exit code. Currently, the code assumes there is
> no need to preserve it for the host, given that it would have been
> assumed clobbered anyway by the function call to __guest_enter().
> Instead, preserve its value and restore it upon return.
>
> Link: https://patchwork.kernel.org/patch/9836891/
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> [Sami: updated commit message, switched from x18 to x29 for the guest
> context]
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>

If you intend for this to be merged via the arm64 tree, please add my

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...