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From: Paolo Bonzini <pbonzini@redhat.com>
To: "Claudio Fontana" <cfontana@suse.de>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>
Subject: Re: all class init functions for all types in QEMU are called in select_machine(). Expected?
Date: Fri, 12 Mar 2021 11:07:26 +0100	[thread overview]
Message-ID: <be88d88a-dd9d-547d-9f3d-7444f0f8bbc6@redhat.com> (raw)
In-Reply-To: <ec7f83ae-8529-3a0e-4b00-73c856b28a3e@suse.de>

On 12/03/21 10:58, Claudio Fontana wrote:
> Not really, but I have been using the accel class init function on x86 to register the TCG OPS,
> 
> and this instead requires a bit more thought for ARM,
> 
> because we currently register for the ARM M Profile the TCG Ops at arm_v7m_class_init time,
> which is called already at select_machine() time,
> 
> so when we select the accelerator, and we call the tcg_cpu_class_init, we run the risk of overriding the existing tcg_ops
>
> Ideas? Looks horrible?

Not horrible, but wrong.  The class_init function must be idempotent: 
classes have no side effect until they're instantiated (and even then, 
usually we delay that to later, e.g. realized for devices or complete 
for user-creatable objects).

Why can't you register ops in the machine init function for the accelerator?

Paolo



  reply	other threads:[~2021-03-12 10:15 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-12  9:31 all class init functions for all types in QEMU are called in select_machine(). Expected? Claudio Fontana
2021-03-12  9:45 ` Philippe Mathieu-Daudé
2021-03-12  9:58   ` Claudio Fontana
2021-03-12 10:07     ` Paolo Bonzini [this message]
2021-03-12 10:25       ` Claudio Fontana
2021-03-12 10:39         ` Paolo Bonzini
2021-03-12 11:51           ` Claudio Fontana
2021-03-12 12:02             ` Paolo Bonzini
2021-03-12 13:40               ` Claudio Fontana
2021-03-12 14:00                 ` Claudio Fontana
2021-03-12 17:04                 ` Paolo Bonzini
2021-03-12 17:24                   ` Claudio Fontana
2021-03-12 17:30                     ` Paolo Bonzini
2021-03-12  9:46 ` Paolo Bonzini
2021-03-12  9:49   ` Claudio Fontana

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