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 924DBC4167B for ; Tue, 5 Dec 2023 17:33:44 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=otyZ+Mj8rb71YhWFv0WOh3X1YJtXFtx9BKuxKJixkOg=; b=Hmx6Eb2xacUlcV aeFxfuyzM+d0oICLhDd97dw2XUI6PmKHyFQhmVb8OLFhW1mrB5yly28kHmMTBDW+Dj8tiS0mTqsqb opRCi4uXGWjU0U80nuuP8da0Tzs3lPPhTVXD/pRz33i4vEkctuNmhU78ru7CCoL3U91nxNv6xUFsa JS5m2qxE8q1rmipXbtf/X2V/Pfu28DBQl2qmc0mAPP3LF9ebzALP/mmZu9s8uMIIWRkggc4uV3V25 aj7oP5QRRaETKWL25yEyDEol2qtRTHZr8GzXcbheCEmKOkl0apeNM6vUIn4VitD5sFM7UDcaxshWz 64PBxoEWRAmUKaspv52A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rAZIH-0082nh-3C; Tue, 05 Dec 2023 17:33:13 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rAZIE-0082mO-2p for linux-arm-kernel@lists.infradead.org; Tue, 05 Dec 2023 17:33:12 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id E4179B819FD; Tue, 5 Dec 2023 17:33:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AC45C433C8; Tue, 5 Dec 2023 17:33:03 +0000 (UTC) Date: Tue, 5 Dec 2023 17:33:01 +0000 From: Catalin Marinas To: Marc Zyngier Cc: Jason Gunthorpe , ankita@nvidia.com, Shameerali Kolothum Thodi , oliver.upton@linux.dev, suzuki.poulose@arm.com, yuzenghui@huawei.com, will@kernel.org, ardb@kernel.org, akpm@linux-foundation.org, gshan@redhat.com, aniketa@nvidia.com, cjia@nvidia.com, kwankhede@nvidia.com, targupta@nvidia.com, vsethi@nvidia.com, acurrid@nvidia.com, apopple@nvidia.com, jhubbard@nvidia.com, danw@nvidia.com, mochs@nvidia.com, kvmarm@lists.linux.dev, kvm@vger.kernel.org, lpieralisi@kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 1/1] KVM: arm64: allow the VM to select DEVICE_* and NORMAL_NC for IO memory Message-ID: References: <20231205033015.10044-1-ankita@nvidia.com> <86fs0hatt3.wl-maz@kernel.org> <20231205130517.GD2692119@nvidia.com> <20231205164318.GG2692119@nvidia.com> <86bkb4bn2v.wl-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <86bkb4bn2v.wl-maz@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231205_093311_082212_B8963BF0 X-CRM114-Status: GOOD ( 16.41 ) 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, Dec 05, 2023 at 05:01:28PM +0000, Marc Zyngier wrote: > On Tue, 05 Dec 2023 16:43:18 +0000, > Jason Gunthorpe wrote: > > On Tue, Dec 05, 2023 at 04:22:33PM +0000, Catalin Marinas wrote: > > > That's an argument to restrict this feature to PCIe. It's really about > > > fewer arguments on the behaviour of other devices. Marc did raise > > > another issue with the GIC VCPU interface (does this even have a vma in > > > the host VMM?). That's a class of devices where the mapping is > > > context-switched, so the TLBI+DSB rules don't help. > > There is no vma. The CPU interface is entirely under control of KVM. > Userspace only provides the IPA for the mapping. That's good to know. We can solve the GIC issue by limiting the relaxation to those mappings that have a user vma. Ideally we should do this for vfio only but we don't have an easy way to convey this to KVM. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel