From: "Emilio G. Cota" <cota@braap.org>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: peter.maydell@linaro.org, rth@twiddle.net, qemu-devel@nongnu.org,
Etienne Carriere <etienne.carriere@linaro.org>,
Joakim Bech <joakim.bech@linaro.org>,
"open list:ARM" <qemu-arm@nongnu.org>
Subject: Re: [PATCH v3 6/6] target/arm: use DISAS_EXIT for eret handling
Date: Mon, 17 Jul 2017 20:14:58 -0400 [thread overview]
Message-ID: <20170718001458.GF30851@flamenco> (raw)
In-Reply-To: <20170711175937.23140-7-alex.bennee@linaro.org>
On Tue, Jul 11, 2017 at 18:59:37 +0100, Alex Bennée wrote:
> Previously DISAS_JUMP did ensure this but with the optimisation of
> 8a6b28c7 (optimize indirect branches) we might not leave the loop.
> This means if any pending interrupts are cleared by changing IRQ flags
> we might never get around to servicing them. You usually notice this
> by seeing the lookup_tb_ptr() helper gainfully chaining TBs together
> while cpu->interrupt_request remains high and the exit_request has not
> been set.
>
> This breaks amongst other things the OPTEE test suite which executes
> an eret from the secure world after a non-secure world IRQ has gone
> pending which then never gets serviced.
>
> Instead of using the previously implied semantics of DISAS_JUMP we use
> DISAS_EXIT which will always exit the run-loop.
>
> CC: Etienne Carriere <etienne.carriere@linaro.org>
> CC: Joakim Bech <joakim.bech@linaro.org>
> CC: Peter Maydell <peter.maydell@linaro.org>
> CC: Emilio G. Cota <cota@braap.org>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Emilio G. Cota <cota@braap.org>
E.
WARNING: multiple messages have this Message-ID (diff)
From: "Emilio G. Cota" <cota@braap.org>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: peter.maydell@linaro.org, rth@twiddle.net, qemu-devel@nongnu.org,
Etienne Carriere <etienne.carriere@linaro.org>,
Joakim Bech <joakim.bech@linaro.org>,
"open list:ARM" <qemu-arm@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH v3 6/6] target/arm: use DISAS_EXIT for eret handling
Date: Mon, 17 Jul 2017 20:14:58 -0400 [thread overview]
Message-ID: <20170718001458.GF30851@flamenco> (raw)
In-Reply-To: <20170711175937.23140-7-alex.bennee@linaro.org>
On Tue, Jul 11, 2017 at 18:59:37 +0100, Alex Bennée wrote:
> Previously DISAS_JUMP did ensure this but with the optimisation of
> 8a6b28c7 (optimize indirect branches) we might not leave the loop.
> This means if any pending interrupts are cleared by changing IRQ flags
> we might never get around to servicing them. You usually notice this
> by seeing the lookup_tb_ptr() helper gainfully chaining TBs together
> while cpu->interrupt_request remains high and the exit_request has not
> been set.
>
> This breaks amongst other things the OPTEE test suite which executes
> an eret from the secure world after a non-secure world IRQ has gone
> pending which then never gets serviced.
>
> Instead of using the previously implied semantics of DISAS_JUMP we use
> DISAS_EXIT which will always exit the run-loop.
>
> CC: Etienne Carriere <etienne.carriere@linaro.org>
> CC: Joakim Bech <joakim.bech@linaro.org>
> CC: Peter Maydell <peter.maydell@linaro.org>
> CC: Emilio G. Cota <cota@braap.org>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Emilio G. Cota <cota@braap.org>
E.
next prev parent reply other threads:[~2017-07-18 0:15 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-11 17:59 [Qemu-devel] [PATCH v3 0/6] arm: fixes for eret, isb and DISAS_UPDATE handling Alex Bennée
2017-07-11 17:59 ` [Qemu-devel] [PATCH v3 1/6] include/exec/exec-all: document common exit conditions Alex Bennée
2017-07-11 18:17 ` Richard Henderson
2017-07-18 0:02 ` Emilio G. Cota
2017-07-11 17:59 ` [PATCH v3 2/6] target/arm/translate: make DISAS_UPDATE match declared semantics Alex Bennée
2017-07-11 17:59 ` [Qemu-devel] " Alex Bennée
2017-07-18 0:07 ` Emilio G. Cota
2017-07-18 0:07 ` [Qemu-devel] " Emilio G. Cota
2017-07-11 17:59 ` [PATCH v3 3/6] target/arm/translate.h: expand comment on DISAS_EXIT Alex Bennée
2017-07-11 17:59 ` [Qemu-devel] " Alex Bennée
2017-07-18 0:08 ` Emilio G. Cota
2017-07-18 0:08 ` [Qemu-devel] " Emilio G. Cota
2017-07-11 17:59 ` [PATCH v3 4/6] target/arm/translate: ensure gen_goto_tb sets exit flags Alex Bennée
2017-07-11 17:59 ` [Qemu-devel] " Alex Bennée
2017-07-11 18:16 ` Richard Henderson
2017-07-11 18:16 ` [Qemu-devel] " Richard Henderson
2017-07-11 19:20 ` Alex Bennée
2017-07-11 19:20 ` [Qemu-devel] " Alex Bennée
2017-07-11 21:08 ` Richard Henderson
2017-07-11 21:08 ` [Qemu-devel] " Richard Henderson
2017-07-11 17:59 ` [PATCH v3 5/6] target/arm: use gen_goto_tb for ISB handling Alex Bennée
2017-07-11 17:59 ` [Qemu-devel] " Alex Bennée
2017-07-11 18:17 ` Richard Henderson
2017-07-11 18:17 ` [Qemu-devel] " Richard Henderson
2017-07-18 0:11 ` Emilio G. Cota
2017-07-18 0:11 ` [Qemu-devel] " Emilio G. Cota
2017-07-11 17:59 ` [PATCH v3 6/6] target/arm: use DISAS_EXIT for eret handling Alex Bennée
2017-07-11 17:59 ` [Qemu-devel] " Alex Bennée
2017-07-18 0:14 ` Emilio G. Cota [this message]
2017-07-18 0:14 ` Emilio G. Cota
2017-07-11 18:18 ` [Qemu-devel] [PATCH v3 0/6] arm: fixes for eret, isb and DISAS_UPDATE handling Richard Henderson
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