Re: Qemu and ARM secure state.

From: "Alex Bennée" <alex.bennee@linaro.org>
To: Jean-Christophe DUBOIS <jcd@tribudubois.net>
Cc: Peter Maydell <peter.maydell@linaro.org>,
	qemu-arm@nongnu.org, QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: Qemu and ARM secure state.
Date: Mon, 08 Nov 2021 14:14:45 +0000	[thread overview]
Message-ID: <87k0hik9yc.fsf@linaro.org> (raw)
In-Reply-To: <e0a1b786-4b1c-c608-495b-3fb839de2376@tribudubois.net>

Jean-Christophe DUBOIS <jcd@tribudubois.net> writes:

> One small question/remark:
>
> According to the the "Arm Power State Coordinate Interface" (DEN0022D.b) document (chapter 5) PSCI calls can only be issued by
> "normal world" (EL1 or EL2). Therefore, should we be adding a test for the current secure state in the arm_is_psci_call() function? This
> would prevent calling the built-in Qemu PSCI function if SMC is issued
> from secure state.

All that should be handled in:

  void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome)

which should cause things to be trapped if the CPU is in an invalid
state to execute the SMC instruction. If the exception is a valid SMC we
end up in arm_cpu_do_interrupt where we may divert to
arm_handle_psci_call.

-- 
Alex Bennée