All of lore.kernel.org
 help / color / mirror / Atom feed
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.

  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170718001458.GF30851@flamenco \
    --to=cota@braap.org \
    --cc=alex.bennee@linaro.org \
    --cc=etienne.carriere@linaro.org \
    --cc=joakim.bech@linaro.org \
    --cc=peter.maydell@linaro.org \
    --cc=qemu-arm@nongnu.org \
    --cc=qemu-devel@nongnu.org \
    --cc=rth@twiddle.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.