[PATCH v2 0/3] Convert sparc devices to new ptimer API

From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"KONRAD Frederic" <frederic.konrad@adacore.com>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	"Mark Cave-Ayland" <mark.cave-ayland@ilande.co.uk>,
	"Fabien Chouteau" <chouteau@adacore.com>
Subject: [PATCH v2 0/3] Convert sparc devices to new ptimer API
Date: Mon, 21 Oct 2019 14:43:54 +0100	[thread overview]
Message-ID: <20191021134357.14266-1-peter.maydell@linaro.org> (raw)

This patchset converts the devices used by sparc machines to the new
ptimer API.

Currently the ptimer design uses a QEMU bottom-half as its mechanism
for calling back into the device model using the ptimer when the
timer has expired.  Unfortunately this design is fatally flawed,
because it means that there is a lag between the ptimer updating its
own state and the device callback function updating device state, and
guest accesses to device registers between the two can return
inconsistent device state. This was reported as a bug in a specific
timer device but it's a problem with the generic ptimer code:
https://bugs.launchpad.net/qemu/+bug/1777777

The updates to the individual ptimer devices are straightforward:
we need to add begin/commit calls around the various places that
modify the ptimer state, and use the new ptimer_init() function
to create the timer.

Changes v1->v2:
 * patches 2 and 3 are the old 1 and 2 and have been reviewed
 * patch 1 is new and removes a pointless NULL check; without
   this we'd probably have got Coverity errors when patch 3
   added a use of t->timer before the check for it being NULL

thanks
--PMM

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*** BLURB HERE ***

Peter Maydell (3):
  hw/timer/slavio_timer: Remove useless check for NULL t->timer
  hw/timer/grlib_gptimer.c: Switch to transaction-based ptimer API
  hw/timer/slavio_timer.c: Switch to transaction-based ptimer API

 hw/timer/grlib_gptimer.c | 28 ++++++++++++++++++++++++----
 hw/timer/slavio_timer.c  | 32 +++++++++++++++++++++-----------
 2 files changed, 45 insertions(+), 15 deletions(-)

-- 
2.20.1