From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 35C62C43458 for ; Tue, 7 Jul 2026 13:21:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wh5jc-0008JZ-7f; Tue, 07 Jul 2026 09:21:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wh5ja-0008JG-LP for qemu-arm@nongnu.org; Tue, 07 Jul 2026 09:21:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wh5jY-0001TV-Q5 for qemu-arm@nongnu.org; Tue, 07 Jul 2026 09:21:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783430468; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UY+kQpjQJvNkHBAz9rCcp3iFT6q7UT+bN2WmOhHMvo4=; b=EOmeb4e+g2XvbIDf6BmTSgoqkaV8MvqjOSEbj/BCrHqKNtJ/Y9e1f819Lw2cwxf5ZZyGqz NTqIBP9VSR+5mNU/EpEu0K+wN8IBK6FPUwqoydKOAu0llm/5XZhNtECz9nJYvIC7sglTE0 yl+OpEHo3JHAo0dM3rLO9Op8NLnomyU= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-399-xCyLTIRuOJSG0i-i0Z4S2g-1; Tue, 07 Jul 2026 09:21:02 -0400 X-MC-Unique: xCyLTIRuOJSG0i-i0Z4S2g-1 X-Mimecast-MFC-AGG-ID: xCyLTIRuOJSG0i-i0Z4S2g_1783430461 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DC3551801322; Tue, 7 Jul 2026 13:21:00 +0000 (UTC) Received: from redhat.com (unknown [10.44.33.142]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id AD6A43692A; Tue, 7 Jul 2026 13:20:56 +0000 (UTC) Date: Tue, 7 Jul 2026 14:20:53 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Mark Cave-Ayland Cc: mst@redhat.com, imammedo@redhat.com, anisinha@redhat.com, philmd@mailo.com, aurelien@aurel32.net, peter.maydell@linaro.org, pbonzini@redhat.com, richard.henderson@linaro.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org Subject: Re: [PATCH v2 02/12] qom/object.c: add object_class_property_add_uint8_ptr() Message-ID: References: <20260703135512.3213964-1-mark.caveayland@nutanix.com> <20260703135512.3213964-3-mark.caveayland@nutanix.com> <84bf8ce3-5595-4b19-a156-180550d7fd4f@nutanix.com> MIME-Version: 1.0 In-Reply-To: <84bf8ce3-5595-4b19-a156-180550d7fd4f@nutanix.com> User-Agent: Mutt/2.3.2 (2026-04-26) X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 X-Mimecast-MFC-PROC-ID: Ov7bCvzIwAjiYoB7-12PvPi248VHak7sQNT4-ZC-WDo_1783430461 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-arm@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-arm-bounces+qemu-arm=archiver.kernel.org@nongnu.org Sender: qemu-arm-bounces+qemu-arm=archiver.kernel.org@nongnu.org On Tue, Jul 07, 2026 at 02:13:24PM +0100, Mark Cave-Ayland wrote: > On 07/07/2026 13:17, Daniel P. Berrangé wrote: > > > On Fri, Jul 03, 2026 at 02:53:04PM +0100, Mark Cave-Ayland wrote: > > > This adds a class property that references a uint8_t within the object instance > > > and is intended to be a replacement for object_property_add_uint8_ptr(). > > > > > > Signed-off-by: Mark Cave-Ayland > > > --- > > > include/qom/object.h | 5 +++++ > > > qom/object.c | 52 ++++++++++++++++++++++++++++++++++++++++++++ > > > 2 files changed, 57 insertions(+) > > > > > > diff --git a/include/qom/object.h b/include/qom/object.h > > > index 89c23d45ab..a55f9d0e97 100644 > > > --- a/include/qom/object.h > > > +++ b/include/qom/object.h > > > @@ -1956,6 +1956,11 @@ ObjectProperty *object_property_add_uint8_ptr(Object *obj, const char *name, > > > const uint8_t *v, > > > ObjectPropertyFlags flags); > > > +ObjectProperty *object_class_property_add_uint8_ptr(ObjectClass *klass, > > > + const char *name, > > > + ptrdiff_t v, > > > + ObjectPropertyFlags flags); > > > + > > > ObjectProperty *object_class_static_property_add_uint8_ptr(ObjectClass *klass, > > > const char *name, > > > const uint8_t *v, > > > diff --git a/qom/object.c b/qom/object.c > > > index d10bf848c0..263c313cd2 100644 > > > --- a/qom/object.c > > > +++ b/qom/object.c > > > @@ -2741,6 +2741,38 @@ static void property_set_uint64_ptr(Object *obj, Visitor *v, const char *name, > > > *field = value; > > > } > > > +static void *object_class_prop_ptr(Object *obj, ptrdiff_t offset) > > > +{ > > > + void *ptr = obj; > > > + ptr += offset; > > > + > > > + return ptr; > > > +} > > > > Perhaps just > > > > #define FIELD(obj, offset) ((void *)obj+(ptrdiff_t)offset) > > That could work. > > > > + > > > +static void property_class_get_uint8_ptr(Object *obj, Visitor *v, > > > + const char *name, > > > + void *opaque, Error **errp) > > > +{ > > > + uint8_t value = *(uint8_t *)object_class_prop_ptr(obj, > > > + (ptrdiff_t)opaque); > > > > Do we need this intermediate instead of now > > > > > + visit_type_uint8(v, name, &value, errp); > > > > visit_type_uint8(v, name, FIELD(obj, opaque), errp); > > Yes, I think that would be possible. I shall give it a test and report back. > > > > +} > > > + > > > +static void property_class_set_uint8_ptr(Object *obj, Visitor *v, > > > + const char *name, > > > + void *opaque, Error **errp) > > > +{ > > > + uint8_t *field = (uint8_t *)object_class_prop_ptr(obj, > > > + (ptrdiff_t)opaque); > > > + uint8_t value; > > > + > > > + if (!visit_type_uint8(v, name, &value, errp)) { > > > + return; > > > + } > > > + > > > + *field = value; > > > > Instead of all this is it sufficient to do: > > > > visit_type_uint8(v, name, FIELD(obj, opaque), errp); > > > > > > Also, since we'll be using this pattern for int8, int16, int32, > > and many more, perhaps we could define a macro that can expand > > to the getter/setter impl for any scalar type. so we can do > > > > DEFINE_SCALAR_PROP_CALLBACKS(uint8); > > DEFINE_SCALAR_PROP_CALLBACKS(uint16); > > DEFINE_SCALAR_PROP_CALLBACKS(uint32); > > DEFINE_SCALAR_PROP_CALLBACKS(uint64); > > DEFINE_SCALAR_PROP_CALLBACKS(bool); > > ..etc.. > > That is something else that is possible: I've purposely avoided doing this > since it's not a pattern already in use within object.c. Do you think this > is worth doing as a separate exercise first? Yeah, if we can convert existing scalar setters/getters that would be nice. Otherwise we're piling up a huge amount of repetitive code for dealing with every property type :-( > > > > +} > > > + > > > ObjectProperty * > > > object_property_add_uint8_ptr(Object *obj, const char *name, > > > const uint8_t *v, > > > ATB, > > Mark. > With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|