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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5737C433E7 for ; Tue, 13 Oct 2020 12:40:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8254D22460 for ; Tue, 13 Oct 2020 12:40:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ZOhokM3p"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="lgLaza4y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727969AbgJMMk6 (ORCPT ); Tue, 13 Oct 2020 08:40:58 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:51748 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727114AbgJMMk5 (ORCPT ); Tue, 13 Oct 2020 08:40:57 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1602592856; h=from:from: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=PtXsyiQpxCT6OGocoDV2xxYXmu++2jlzkrSoN+j9pRU=; b=ZOhokM3pscswWs/6L/+yp+pNzzbKR8c7jaCklmGODRNv2mGh7LTgmNcJF1kgPKaKPP+ksr uEHGxq9JgpE2/P1IDDG9/5nfdviWuSte26uh3HKiCx6Tm0Fmb3W/qvLWuC2LQfR1ccLXMH 4tVYwoWAVXzXkkxyGlg+PBU4sIPlNJwxNgJcjD9OIDv6jsUTaHFJGmuFFTbEeC4TaOSX5R NCUUg36m0CJydtFo2o/uTABAnL3RiTFrVX+tILyri7ynuhNEJel+bt9y04AMjKRe/ySqBk SZ1C/1reHxc0mu5bM9DqROwiunnooF60MKgeRGq+Vu1+ijO7eCKAJkuWTOn6VQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1602592856; h=from:from: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=PtXsyiQpxCT6OGocoDV2xxYXmu++2jlzkrSoN+j9pRU=; b=lgLaza4y48L6oQOyRBy1XqLgy1HeZ9SOaSeFB0Jhx8gOY+Qc/KdONfuORVzmHeb7Wv/FQ2 BFc4wukp3LfMQcDA== To: David Woodhouse , x86@kernel.org, Marc Zyngier Cc: kvm , Paolo Bonzini , linux-kernel Subject: Re: [PATCH 5/5] x86/kvm: Add KVM_FEATURE_MSI_EXT_DEST_ID In-Reply-To: <0ca196c0df5beb90b45457ac7ca5d8611d2a7a29.camel@infradead.org> References: <803bb6b2212e65c568c84ff6882c2aa8a0ee03d5.camel@infradead.org> <95625dfce360756b99641c31212634c1bf80a69a.camel@infradead.org> <87362owhcb.fsf@nanos.tec.linutronix.de> <87tuv4uwmt.fsf@nanos.tec.linutronix.de> <958f0d5c9844f94f2ce47a762c5453329b9e737e.camel@infradead.org> <874kn2s3ud.fsf@nanos.tec.linutronix.de> <0E51DAB1-5973-4226-B127-65D77DC46CB5@infradead.org> <87pn5or8k7.fsf@nanos.tec.linutronix.de> <87ft6jrdpk.fsf@nanos.tec.linutronix.de> <25c54f8e5da1fd5cf3b01ad2fdc1640c5d86baa1.camel@infradead.org> <87362jqoh3.fsf@nanos.tec.linutronix.de> <1abc2a34c894c32eb474a868671577f6991579df.camel@infradead.org> <87eem3ozxd.fsf@nanos.tec.linutronix.de> <0de733f6384874d68afba2606119d0d9b1e8b34e.camel@infradead.org> <87zh4qo4o5.fsf@nanos.tec.linutronix.de> <87wnzuo127.fsf@nanos.tec.linutronix.de> <832c2d4c11cd99382782474f51d15889ffa24407.camel@infradead.org> <0ca196c0df5beb90b45457ac7ca5d8611d2a7a29.camel@infradead.org> Date: Tue, 13 Oct 2020 14:40:55 +0200 Message-ID: <87tuuynvs8.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 13 2020 at 12:51, David Woodhouse wrote: > With that realisation, I've fixed the comment in my ext_dest_id branch > to remove all mention of IRQ remapping. It now looks like this: > > static int x86_vector_select(struct irq_domain *d, struct irq_fwspec *fws= pec, > enum irq_domain_bus_token bus_token) > { > /* > * HPET and I/OAPIC drivers use irq_find_matching_irqdomain() > * to find their parent irqdomain. For x86_vector_domain to be > * suitable, all CPUs in the system must be reachable by its > * x86_vector_msi_compose_msg() function. Which is only true > * in !x2apic mode, or in x2apic physical mode if APIC IDs were > * restricted to 8 or 15 bits at boot time. In those cases, > * 1<<15 will *not* be a valid APIC ID. > */ > if (apic->apic_id_valid(1<<15)) > return 0; > > return x86_fwspec_is_ioapic(fwspec) || x86_fwspec_is_hpet(fwspec); > } > > That makes it clearer that this isn't just some incestuous interaction > with IRQ remapping =E2=80=94 that APIC ID limit really is the basis on wh= ich > this irqdomain, all by itself, makes the decision about whether it's > capable of being the parent irqdomain to the requesting device. Yes, that makes sense now. Thanks, tglx