From: Markus Armbruster <armbru@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
"Daniel P. Berrange" <berrange@redhat.com>,
Laurent Vivier <laurent@vivier.eu>,
Eduardo Habkost <ehabkost@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [PATCH 09/24] macio: Fix to realize "mos6522-cuda" and "mos6522-pmu" devices
Date: Mon, 25 May 2020 08:25:22 +0200 [thread overview]
Message-ID: <87367oh6p9.fsf@dusky.pond.sub.org> (raw)
In-Reply-To: <CAFEAcA_S_JsuPG4UN-_zhhdZppBhiwm3-4bocO7O1XdjxC9bAw@mail.gmail.com> (Peter Maydell's message of "Thu, 21 May 2020 17:26:50 +0100")
Peter Maydell <peter.maydell@linaro.org> writes:
> On Mon, 18 May 2020 at 06:12, Markus Armbruster <armbru@redhat.com> wrote:
>>
>> cuda_init() creates a "mos6522-cuda" device, but it's never realized.
>> Affects machines mac99 with via=cuda (default) and g3beige.
>>
>> pmu_init() creates a "mos6522-pmu" device, but it's never realized.
>> Affects machine mac99 with via=pmu and via=pmu-adb,
>>
>> I wonder how this ever worked. If the "device becomes real only on
>> realize" thing actually works, then we've always been missing these
>> devices, yet nobody noticed.
>
> Same remark as elsewhere: the devices aren't missing, we just
> got lucky that using them in a half-initialized state happens
> to work for these devices. Could you update the commit messages
> when you reroll this series, please?
Of course. What about something like this:
In theory, a device becomes real only on realize. In practice, the
transition from unreal to real is a fuzzy one. The work to make a
device real can be spread between realize methods (fine),
instance_init methods (wrong), and board code wiring up the device
(fine as long as it effectively happens on realize). Depending on
what exactly is done where, a device can work even when we neglect
to realize it. Nevertheless, it's a clear misuse of the interface.
Even when it works today (more or less by chance), it can break
tomorrow.
>> Fix by realizing them in cuda_realize() and pmu_realize(),
>> respectively.
>>
>> Fixes: 6dca62a0000f95e0b7020aa00d0ca9b2c421f341
>> Cc: Laurent Vivier <laurent@vivier.eu>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>> hw/misc/macio/cuda.c | 8 +++-----
>> hw/misc/macio/pmu.c | 8 +++-----
>> 2 files changed, 6 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c
>> index e0cc0aac5d..6d4d135f71 100644
>> --- a/hw/misc/macio/cuda.c
>> +++ b/hw/misc/macio/cuda.c
>> @@ -523,15 +523,13 @@ static void cuda_realize(DeviceState *dev, Error **errp)
>> {
>> CUDAState *s = CUDA(dev);
>> SysBusDevice *sbd;
>> - MOS6522State *ms;
>> - DeviceState *d;
>> struct tm tm;
>>
>> + qdev_init_nofail(DEVICE(&s->mos6522_cuda));
>
> Since we init the device with sysbus_init_child_obj() and
> we're in a position here to propagate any realize error
> back up to our caller, it would be nicer to do this via
> setting the realize property rather than qdev_init_nofail().
The error handling will be unreachable.
The proper way to say "error not possible" is of course &error_abort,
not qdev_init_nofail()'s &error_fatal.
Many realize methods misuse the Error interface this way. NULL instead
of &error_abort is also common. Cleaning this up is yet another big
task. But that's no excuse for making it bigger now.
Laurent, would you prefer unreachable error handling or &error_abort?
> That's what this patch from March does:
> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg04260.html
> (we seem to have let that series drop accidentally,
> probably because it was halfway through release and
> because it touches several architectures at once).
Pity.
next prev parent reply other threads:[~2020-05-25 6:26 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-18 5:03 [PATCH 00/24] Fixes around device realization Markus Armbruster
2020-05-18 5:03 ` [PATCH 01/24] arm/stm32f405: Fix realization of "stm32f2xx-adc" devices Markus Armbruster
2020-05-18 16:48 ` Alistair Francis
2020-05-19 5:08 ` Markus Armbruster
2020-05-19 22:20 ` Alistair Francis
2020-05-27 9:27 ` Markus Armbruster
2020-05-27 11:24 ` Philippe Mathieu-Daudé
2020-05-18 5:03 ` [PATCH 02/24] display/xlnx_dp: Fix to realize "i2c-ddc" and "aux-to-i2c-bridge" Markus Armbruster
2020-05-18 8:19 ` Fred Konrad
2020-05-19 5:09 ` Markus Armbruster
2020-05-19 9:48 ` Peter Maydell
2020-05-19 12:07 ` Markus Armbruster
2020-05-18 9:59 ` Edgar E. Iglesias
2020-05-18 10:30 ` Peter Maydell
2020-05-18 11:13 ` Philippe Mathieu-Daudé
2020-05-19 5:13 ` Markus Armbruster
2020-05-18 16:56 ` Alistair Francis
2020-05-18 5:03 ` [PATCH 03/24] sd/pxa2xx_mmci: Fix to realize "pxa2xx-mmci" device Markus Armbruster
2020-05-21 16:20 ` Peter Maydell
2020-05-18 5:03 ` [PATCH 04/24] aspeed: Don't create unwanted "ftgmac100", "aspeed-mmi" devices Markus Armbruster
2020-05-18 12:19 ` Cédric Le Goater
2020-05-19 0:20 ` Andrew Jeffery
2020-05-19 5:45 ` Markus Armbruster
2020-05-19 11:42 ` Philippe Mathieu-Daudé
2020-05-19 12:44 ` Cédric Le Goater
2020-05-19 0:38 ` Joel Stanley
2020-05-19 5:35 ` Markus Armbruster
2020-05-18 5:03 ` [PATCH 05/24] aspeed: Don't create unwanted "cortex-a7-arm-cpu" devices Markus Armbruster
2020-05-18 12:24 ` Cédric Le Goater
2020-05-19 0:40 ` Joel Stanley
2020-05-19 5:46 ` Markus Armbruster
2020-05-19 9:35 ` Cédric Le Goater
2020-05-18 5:03 ` [PATCH 06/24] armv7m: Bury unwanted "ARM,bitband-memory" devices Markus Armbruster
2020-05-21 16:17 ` Peter Maydell
2020-05-25 5:50 ` Markus Armbruster
2020-05-25 12:32 ` Paolo Bonzini
2020-05-25 12:49 ` Peter Maydell
2020-05-26 5:19 ` Markus Armbruster
2020-05-18 5:03 ` [PATCH 07/24] auxbus: Fix aux-to-i2c-bridge to be a subtype of aux-slave Markus Armbruster
2020-05-18 8:53 ` Philippe Mathieu-Daudé
2020-05-18 5:03 ` [PATCH 08/24] mac_via: Fix to realize "mos6522-q800-via*" devices Markus Armbruster
2020-05-18 20:25 ` Mark Cave-Ayland
2020-05-18 5:03 ` [PATCH 09/24] macio: Fix to realize "mos6522-cuda" and "mos6522-pmu" devices Markus Armbruster
2020-05-21 16:26 ` Peter Maydell
2020-05-25 6:25 ` Markus Armbruster [this message]
2020-05-27 14:12 ` Markus Armbruster
2020-05-27 15:05 ` Peter Maydell
2020-05-27 15:12 ` Paolo Bonzini
2020-05-28 6:57 ` Markus Armbruster
2020-05-27 16:08 ` Markus Armbruster
2020-05-18 5:03 ` [PATCH 10/24] macio: Bury unwanted "macio-gpio" devices Markus Armbruster
2020-05-18 20:35 ` Mark Cave-Ayland
2020-05-19 6:06 ` Markus Armbruster
2020-05-18 5:03 ` [PATCH 11/24] pnv/phb4: Bury unwanted "pnv-phb4-pec-stack" devices Markus Armbruster
2020-05-18 8:49 ` Greg Kurz
2020-05-18 13:24 ` Cédric Le Goater
2020-05-19 8:16 ` Cédric Le Goater
2020-05-19 11:50 ` Markus Armbruster
2020-05-18 5:03 ` [PATCH 12/24] MAINTAINERS: Make section PowerNV cover pci-host/pnv* as well Markus Armbruster
2020-05-18 6:41 ` David Gibson
2020-05-18 5:03 ` [PATCH 13/24] ppc4xx: Drop redundant device realization Markus Armbruster
2020-05-18 8:54 ` Philippe Mathieu-Daudé
2020-05-18 10:27 ` BALATON Zoltan
2020-05-19 6:07 ` Markus Armbruster
2020-05-18 16:41 ` Thomas Huth
2020-05-18 5:03 ` [PATCH 14/24] macio: Put "macio-nvram" device on the macio bus Markus Armbruster
2020-05-18 20:37 ` Mark Cave-Ayland
2020-05-18 5:03 ` [PATCH 15/24] macio: Fix macio-bus to be a subtype of System bus Markus Armbruster
2020-05-18 8:55 ` Philippe Mathieu-Daudé
2020-05-18 20:39 ` Mark Cave-Ayland
2020-05-19 6:09 ` Markus Armbruster
2020-05-18 5:04 ` [PATCH 16/24] ppc/pnv: Put "*-pnv-chip" and "pnv-xive" on the main system bus Markus Armbruster
2020-05-18 16:34 ` Cédric Le Goater
2020-05-19 6:28 ` Markus Armbruster
2020-05-19 13:05 ` Cédric Le Goater
2020-05-18 5:04 ` [PATCH 17/24] pnv/psi: Correct the pnv-psi* devices not to be sysbus devices Markus Armbruster
2020-05-18 16:27 ` Cédric Le Goater
2020-05-19 6:30 ` Markus Armbruster
2020-05-19 13:04 ` Cédric Le Goater
2020-05-18 5:04 ` [PATCH 18/24] display/sm501 display/ati: Fix to realize "i2c-ddc" Markus Armbruster
2020-05-18 10:32 ` BALATON Zoltan
2020-05-19 6:30 ` Markus Armbruster
2020-05-18 10:39 ` BALATON Zoltan
2020-05-18 10:45 ` Philippe Mathieu-Daudé
2020-05-19 6:35 ` Markus Armbruster
2020-05-18 5:04 ` [PATCH 19/24] riscv: Fix to put "riscv.hart_array" devices on sysbus Markus Armbruster
2020-05-18 17:03 ` Alistair Francis
2020-05-18 5:04 ` [PATCH 20/24] riscv: Fix type of SiFive[EU]SocState, member parent_obj Markus Armbruster
2020-05-18 8:58 ` Philippe Mathieu-Daudé
2020-05-18 16:57 ` Alistair Francis
2020-05-18 5:04 ` [PATCH 21/24] sparc/leon3: Fix to put grlib,* devices on sysbus Markus Armbruster
2020-05-18 8:09 ` Fred Konrad
2020-05-18 8:59 ` Philippe Mathieu-Daudé
2020-05-18 5:04 ` [PATCH 22/24] qdev: Assert devices are plugged into a bus that can take them Markus Armbruster
2020-05-18 15:03 ` Markus Armbruster
2020-05-18 20:42 ` Mark Cave-Ayland
2020-05-18 5:04 ` [PATCH 23/24] sd: Hide the qdev-but-not-quite thing created by sd_init() Markus Armbruster
2020-05-18 5:04 ` [PATCH 24/24] qdev: Assert onboard devices all get realized properly Markus Armbruster
2020-05-18 9:10 ` Philippe Mathieu-Daudé
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