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 lists.gnu.org (lists.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 6774BC52D6F for ; Thu, 8 Aug 2024 11:57:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sc1lT-0005Oh-Te; Thu, 08 Aug 2024 07:57:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sc1lS-0005MO-Gj for qemu-devel@nongnu.org; Thu, 08 Aug 2024 07:57:06 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sc1lQ-0000eS-VU for qemu-devel@nongnu.org; Thu, 08 Aug 2024 07:57:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723118224; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/MDW/fCmOPam4z1yODWWWoU72ehPEXs0cRfoHw6hIY0=; b=a9Ukfh6YBsEPAR4CN792d5Df6vb/M40qttyppGHQkRJsRQKO7a2tLfBuzxNSqX+XEZma01 M0eDBhnpaTYoszMjXaEXssUyua6H17KqRwId0piISM46pYiD/Ngf075etn6mbOFSiNyv1a tdb4HDkETo1mDhH/bfZmMJqaHaq1IsM= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-518-4e1D9GJdPYy52WbCtmsZsA-1; Thu, 08 Aug 2024 07:57:01 -0400 X-MC-Unique: 4e1D9GJdPYy52WbCtmsZsA-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 279D71944B2D; Thu, 8 Aug 2024 11:57:00 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.163]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 05DFC19560AE; Thu, 8 Aug 2024 11:56:56 +0000 (UTC) Date: Thu, 8 Aug 2024 12:56:53 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Maydell , Markus Armbruster , Richard Henderson , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Eric Blake , qemu-arm@nongnu.org, Thomas Huth Subject: Re: [RFC PATCH-for-9.1? 1/2] target/arm: Move qmp_query_gic_capabilities() to hw/intc/ Message-ID: References: <20240806141940.22095-2-philmd@linaro.org> <87bk23skhq.fsf@pond.sub.org> <87ed6z1j77.fsf@pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.141, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@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-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Aug 08, 2024 at 12:48:39PM +0100, Daniel P. Berrangé wrote: > On Thu, Aug 08, 2024 at 12:32:35PM +0100, Peter Maydell wrote: > > On Thu, 8 Aug 2024 at 12:23, Daniel P. Berrangé wrote: > > > On Thu, Aug 08, 2024 at 11:15:17AM +0100, Peter Maydell wrote: > > > > It's not possible to use KVM with that machine type, so the > > > > question is a bit moot. (This also indicates that the > > > > interface is not very helpful -- it purports to tell the > > > > management layer whether it can use an accelerated in-kernel > > > > GIC, but because it doesn't specifiy the board type there's > > > > no way to provide an accurate answer. It would be useful > > > > to know exactly what libvirt/etc actually use this for...) > > > > > > Libvirt uses this exclusively with the arm 'virt' machine type. > > > > > > If the user didn't express any GIC preference, then if KVM is in use, > > > we'll pick the highest GIC version QEMU reports as supported. > > > > You can get that without querying QEMU by asking for 'gic-version=max' > > if you like. > > This isn't in the VM startup path. It is when we expand the user > provided XML config into an ABI stable XML config by filling in > the blanks left by the user. So we need to actually query the > values available. > > > > If TCG > > > is in use we'll always pick v2, even if QEMU reports v3 is emulatable > > > due to the v3 impl lacking MSI controller which we need for PCI-e > > > > Our emulated GICv3 supports the ITS which has MSI support, so I'm not > > sure what forcing GICv2 is getting you here. Looking at the linked > > RHEL bugzilla bug, I suspect this is an out-of-date policy from before > > we added the ITS emulation in 2021 (it's present by default > > in virt-2.8 and later machine types). So that is something that > > libvirt should update I think. > > It looks like it is virt-6.2 or later, and libvirt can probe it > by looking for existence of the arm-gicv3-its QOM type IIUC. https://gitlab.com/libvirt/libvirt/-/issues/659 With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|