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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FBFFC54EE9 for ; Tue, 20 Sep 2022 16:08:26 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1564F4B62C; Tue, 20 Sep 2022 12:08:26 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rcOb6oy5DNHh; Tue, 20 Sep 2022 12:08:24 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 768254B24D; Tue, 20 Sep 2022 12:08:24 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2E0384B24D for ; Tue, 20 Sep 2022 12:08:23 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pplmwQUCxswb for ; Tue, 20 Sep 2022 12:08:21 -0400 (EDT) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id DAD094B210 for ; Tue, 20 Sep 2022 12:08:21 -0400 (EDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6B14B61CE1; Tue, 20 Sep 2022 16:08:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF2E9C433D6; Tue, 20 Sep 2022 16:08:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663690099; bh=GBl1obNqYWAGzVEi2bHUxfF1zOhV7ve3V8otgRy3yd8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=md1NJ6KK2nMgnyTDB+RcjhYntKlY8hfCT7K/lmEyxgnXUbbpE8DqS0X8p3DZG50At FMYZt6xEWYXqTrzBweIqPBuJUF8aUh6WrxqaHri20TSoJNUfALUgfgHgb4LE9bnfhW QIsXBDj8zb2avrw0WpSZGEgttsURyyf850KWfxMCCaMKbFtO54uHHuRcbpUADd9gvM FQuMYJHLeR2eUHymaySlF6hp5vAbZxu/osiqkZtZiHHEFXKjbkqdc+rHfWeXtVny+l nkDN3a8LoPgbMZ8jHc1X4BjJFl7Gk/5iXZwWKZEGQ2Cp1WWYzH0s2wJIrafovk+6pp pQ4Osy7xdXjwA== Received: from 185-176-101-241.host.sccbroadband.ie ([185.176.101.241] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oafnF-00BRoi-Ez; Tue, 20 Sep 2022 17:08:17 +0100 Date: Tue, 20 Sep 2022 17:08:13 +0100 Message-ID: <874jx2kp02.wl-maz@kernel.org> From: Marc Zyngier To: Alexey Kardashevskiy Subject: Re: [PATCH kernel v2] KVM: PPC: Make KVM_CAP_IRQFD_RESAMPLE support platform dependent In-Reply-To: <20220920125143.28009-1-aik@ozlabs.ru> References: <20220920125143.28009-1-aik@ozlabs.ru> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.176.101.241 X-SA-Exim-Rcpt-To: aik@ozlabs.ru, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm-riscv@lists.infradead.org, pbonzini@redhat.com, anup@brainfault.org, kvm-ppc@vger.kernel.org, npiggin@gmail.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, Nicholas Piggin , kvm-riscv@lists.infradead.org, Paolo Bonzini , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Tue, 20 Sep 2022 13:51:43 +0100, Alexey Kardashevskiy wrote: > > When introduced, IRQFD resampling worked on POWER8 with XICS. However > KVM on POWER9 has never implemented it - the compatibility mode code > ("XICS-on-XIVE") misses the kvm_notify_acked_irq() call and the native > XIVE mode does not handle INTx in KVM at all. > > This moved the capability support advertising to platforms and stops > advertising it on XIVE, i.e. POWER9 and later. > > Signed-off-by: Alexey Kardashevskiy > Acked-by: Nicholas Piggin > [For KVM RISC-V] > Acked-by: Anup Patel > --- > Changes: > v2: > * removed ifdef for ARM64. The same argument applies to both x86 and s390, which do select HAVE_KVM_IRQFD from the KVM config option. Only power allows this option to be selected depending on the underlying interrupt controller emulation. As for riscv and mips, they don't select HAVE_KVM_IRQFD, and this isn't a user-selectable option. So why do they get patched at all? My conclusion is that: - only power needs the #ifdefery in the arch-specific code - arm64, s390 and x86 can use KVM_CAP_IRQFD_RESAMPLE without a #ifdef - mips and riscv should be left alone Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm