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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 DF30CECAAD8 for ; Tue, 20 Sep 2022 16:09:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=dDDw6DTfWROQdlQiGEqF31UiCpmimyHbK0SChieUajc=; b=JtmXKcOsxvLKMm FcJiHNQyXEMVmWdXJ1uVjH0nsoCjIOc+9bWG7a1M0RVh0hsh0wz2OyfbeLd1r2vtx7zA4ibY3TVyP c5Jkz1IXlhTAWVtUQ1Lbb1HHbEYmUNuTZyZHBEdhtIdEafPe5aG9MYgyCfOXe8CJaY1/OSZM4gB6n Zsst1fRpcEa5AX0EqhL+ZMwHO0nuzYuLig3K9OR19KgYIw/Ia7rKNp70atd0Tlix69p+Xp2wN+zwR jdnh1rahQGeaN/RlpuR1hRxiTqUsExVhSldmMS2I7+xzTJamlqYu/q3opzcTlUET3xuNHL83ChXwO 9JRQKgfVmdDJ7W+3P6Lw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oafnM-00551B-JM; Tue, 20 Sep 2022 16:08:24 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oafnJ-00550W-4m; Tue, 20 Sep 2022 16:08:22 +0000 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 Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm-riscv@lists.infradead.org, Paolo Bonzini , Anup Patel , kvm-ppc@vger.kernel.org, Nicholas Piggin 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220920_090821_246293_28E55FB8 X-CRM114-Status: GOOD ( 18.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel