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 6752BCD98F2 for ; Tue, 23 Jun 2026 11:11:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=XivQlvdLpY7xpybLVo/eZqqbhvnd91yNEkwRxW/Nj+0=; b=DvN9rXKaZUbJ1R5ImXNb5sB+sw aKPLZI31KeEsTsxho6Io5GDphsrMrc1eZz/t3VtvoBCf5DHzWWwyrY2T3ZbKHPKE/Ml858gQGzRa8 cw9ppxgMMBXILwsTq9jd6FwwahBfdd+qO/UFu9h3w7d0WCZl5Fs7wswMI8tCfN68pUBocb4hkNa1e EgfzHvpD0K4fkkH6uG5yEaRbyAgPegWyjQhu/g0zwIh3XBIlHhhy7O7gUMyr9AZ/jPRE5xaUni/8G R2GwkJEOAzF0mDFP6oACslueXgMteHK7ZZTxbKJzg/ky4SBOmgk2CbIcaaYxpjQj9dtPMU41FiTFr kudSgzOA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wbxnZ-000000062Rz-1Szp; Tue, 23 Jun 2026 09:52:05 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wbxnY-000000062Rr-0MXD for linux-arm-kernel@lists.infradead.org; Tue, 23 Jun 2026 09:52:04 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 6EE854047A; Tue, 23 Jun 2026 09:52:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 514AD1F000E9; Tue, 23 Jun 2026 09:52:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782208323; bh=XivQlvdLpY7xpybLVo/eZqqbhvnd91yNEkwRxW/Nj+0=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=UhJBtUZ+qJJgbWifFXxmwUaQmvPokIta/Q7oxVwplPk9Npvq78MCNcVdlDsq3oeqg yGc+nA1Yn6tpBEaejUqk4tme0U6/T9knWP0uj57Tk5NOmE5DVysH52W/mg4EHvppYN 3kTSresu858j8BdWotWSSX6NusI761XNiLbxWZRaHkXT0IL+n1XtsB5Mn7/LTE8ivX C10SsT4qRieh1HdzE+CqZAqA86hhzs1xzMcM0W2EfUwFgvJRtRgTjaTBZoMyhusjly 3v9SGvdBEoZu6SGZNYbf+N9uCymyEfojOgQoCF7zB3oUJkeyrO3x+f+nmmgSVWeYKW T1yCPqj6jFfOA== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wbxnU-0000000FE6l-44hg; Tue, 23 Jun 2026 09:52:01 +0000 Date: Tue, 23 Jun 2026 10:52:00 +0100 Message-ID: <86v7b9r3cv.wl-maz@kernel.org> From: Marc Zyngier To: leixiang Cc: oupton@kernel.org, seanjc@google.com, pbonzini@redhat.com, kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Eric Auger Subject: Re: [RFC PATCH] KVM: arm64: Set irqfd->producer to enable vLPI routing updates In-Reply-To: <20260623081433.21250-1-leixiang@kylinos.cn> References: <20260622075103.35164-1-leixiang@kylinos.cn> <20260623081433.21250-1-leixiang@kylinos.cn> 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/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: leixiang@kylinos.cn, oupton@kernel.org, seanjc@google.com, pbonzini@redhat.com, kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, eauger@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org + Eric On Tue, 23 Jun 2026 09:14:33 +0100, leixiang wrote: > > ARM64's kvm_arch_irq_bypass_add_producer() never sets irqfd->producer, > so kvm_irq_routing_update() never calls the ARM64 routing hook. That > hook unmaps the vLPI and falls back to software injection when an > irqfd's MSI routing changes; with it dead, the vLPI stays bound to the > old translation. /confused. Why should userspace be in control of anything? There is no real "routing" involved (that's the guest's responsibility), and we are really trying to hide the fact that VLPIs are used to deliver guest-visible LPIs. Can you explain what this is achieving? Thanks, M. -- Without deviation from the norm, progress is not possible.