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 DE921C3DA4A for ; Thu, 8 Aug 2024 12:06:21 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sc1tZ-0003yX-7C; Thu, 08 Aug 2024 08:05:29 -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 1sc1tU-0003x8-KH for qemu-devel@nongnu.org; Thu, 08 Aug 2024 08:05:26 -0400 Received: from mail-ed1-x52b.google.com ([2a00:1450:4864:20::52b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sc1tJ-0002kc-5b for qemu-devel@nongnu.org; Thu, 08 Aug 2024 08:05:18 -0400 Received: by mail-ed1-x52b.google.com with SMTP id 4fb4d7f45d1cf-5bb8e62575eso267445a12.3 for ; Thu, 08 Aug 2024 05:05:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1723118709; x=1723723509; darn=nongnu.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Ie9/zshnXJahaSjDJyr5B0VRG7Ex38kTtZj2BwALYOY=; b=A+SDeZXrrZIuT0ZoY/zIiiuyYmqkIjw91XmfvP8bGccIkByT+8GjLVXtHCOvYoyayL N8qTG6Ne58RTx8AxRuijSJQuWhsjkBHinLX1Et7H9chf/E8J4ggYgBnSgLuFa3cwhLRO lKbM153onnW1daZbFZT4QOkneIIau0etxWRVTJoPnmLVIf+r6fsHvwBtYu/t2KCCmm0/ KiJx/moDwbrHVQZJJa0iE7bBrMMBv7sv5huqLdN+UswNKqvxY3f/iIfj5jroaVgY8jcb ruWqCytZR+8ZeJRfj/xEiGSmAYY3k4cYMoYu4GtfViogEpB8oZixVFMiKGvfH92xME/e gOAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723118709; x=1723723509; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ie9/zshnXJahaSjDJyr5B0VRG7Ex38kTtZj2BwALYOY=; b=SzG91MOTQugn9HguzYLP2kcdnemtUNHb660X8UKXdAUPU6F2QWEsnK/pMv+QeCO6IR dlaeC7Lkg5FX6hH68871BWdWrZ0YP38fOrw557+nZqvbA9McGdbzVINt29UjfcwijfKd PyYlYtNqlviGb7IYtzu3Taaxp/kpDMlixiH1rbArnK2pwfD2mNg0hppU9hNTa7p9xmmM +38+d9m+7uAW2iuF7XGYMDduwodcBNdbPLn1ZaeUCLTvGCXxHkfuMcIKanfqIjee1d0I 5KpmAQ2FWB311e1FOfijugmUtaOgegiaVSqxsKO7CAQbjA4hBPCpHhfCqq5+4rJeMfu7 Wh7Q== X-Forwarded-Encrypted: i=1; AJvYcCVKXr/cWXOpm2ibFYg2xJ9b/8DVenv8RE1oOZu9yj1ZnRdsZ9OCQZ8lBedRHxy+vUPYN4iPiYNvqbS8KQTRlxZ6pYVAgkw= X-Gm-Message-State: AOJu0Yyb0T0UzKW5onIpMEMYVZ2KzRkL+ppnQZ3l7nuX6rpMiDbge7h9 es1fXm2ctQsMZVaks23GgWBdBGhKb1T1dTEk+YK6ShDkrdtipbvXT2WXTVvxAN29eDMbaLzIEhM UZc67fBOSrlDbrX+KLRl+tFarQYPYewzXiBHwtQ== X-Google-Smtp-Source: AGHT+IGMDM0cbDlPBhRjwdc+E6prr95O7WFyn8nu2feRlNjHFPyE7jel1d7FCeABtOX6UXE8zNxPeK66X/SmYOk1m7U= X-Received: by 2002:a05:6402:13d3:b0:5a1:f9bc:7f13 with SMTP id 4fb4d7f45d1cf-5bbb235ae4dmr2037485a12.22.1723118709019; Thu, 08 Aug 2024 05:05:09 -0700 (PDT) MIME-Version: 1.0 References: <20240806141940.22095-1-philmd@linaro.org> <20240806141940.22095-2-philmd@linaro.org> <87bk23skhq.fsf@pond.sub.org> <87ed6z1j77.fsf@pond.sub.org> In-Reply-To: From: Peter Maydell Date: Thu, 8 Aug 2024 13:04:58 +0100 Message-ID: Subject: Re: [RFC PATCH-for-9.1? 1/2] target/arm: Move qmp_query_gic_capabilities() to hw/intc/ To: =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= Cc: Markus Armbruster , Richard Henderson , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , qemu-devel@nongnu.org, Eric Blake , qemu-arm@nongnu.org, Thomas Huth Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2a00:1450:4864:20::52b; envelope-from=peter.maydell@linaro.org; helo=mail-ed1-x52b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: , 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, 8 Aug 2024 at 12:54, Daniel P. Berrang=C3=A9 = wrote: > > On Thu, Aug 08, 2024 at 12:32:35PM +0100, Peter Maydell wrote: > > On Thu, 8 Aug 2024 at 12:23, Daniel P. Berrang=C3=A9 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=3Dmax= ' > > 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. Yes. (I was confused by the 'no_its' setting in virt-2.8, but that is for "is there a KVM ITS", and no_tcg_its is separate and as you say added with 6.2.) -- PMM