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 572F6C6FA82 for ; Wed, 21 Sep 2022 17:32:45 +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=qTGc5FDEj1UPJ0IXYcrh6frVRYjcjV0C8UrLNrvHZMI=; b=ai8fjbvvyN2hOX mdw0CPimhljazOrNV1ytu81Hs5CIOTacVhqHbaiz9QICgWBEx84bmIImCJVcy9WDtsxOHgrvMxfo6 npkkwsASVJ3nHdlLl7N7WtIhoosZaRiWgUN+Sg0M0JBRqyuaqv6Ggj0teoJ86U3fOXV8zHKSN9wep gmiI04VctL8aRpGX1GZ0Na96vmbOX7Bi4UybelwSh3eEPcJBwrhjnNHtv56U/BtKXj0A9G+bLV/sY 6FgjQPWtw6+JAl5idjmtHJ0Rrp9W0zLfR0+gV4Lpo34QgdWmw/uc+rfEX+jbL67QiQesjmNaRAKj2 ot4+sptCa+7uzz5PkQLA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ob3ZW-00CCKU-8m; Wed, 21 Sep 2022 17:31:42 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ob3ZO-00CCJc-O1 for linux-arm-kernel@lists.infradead.org; Wed, 21 Sep 2022 17:31:41 +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 ams.source.kernel.org (Postfix) with ESMTPS id EA026B82889; Wed, 21 Sep 2022 17:31:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC6ACC433C1; Wed, 21 Sep 2022 17:31:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663781491; bh=OEpDSs8Idj+f6sm81NSd/vFypq2q+42hxd0d/9RHaU8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pKSIt8StaUsJiY8qnVFQ8+XS/CU2701FmYS11ZOu2HGTxM0KwGrcIc+loxxqzHi63 yvA/FkYQ6bCHZW1y4CkIGuJ7HFf1IPoZGjEx4it7mTYQ6j6hquMJ3SdxByS9Y8Hk+6 0OKwpaBBKviuafOrZkpZEnipnk4viaT8n7xZiJ8ofAlpvCgYxX/Kq9GPGJWC4QJJrk yWoPTAhM4A7r0wg7oU42vSb1IMJSsHnItm+U9uY8+EZVktZlOP5z/uOEKKpGxT5YpY PQYINpuGHOrWKa5p6JRIXBaIpSzixPuQOreayHeMKMuVDqF9WG6Z9BmmlLTTetGy6C pt1/jC8iDKWWw== 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 1ob3ZJ-00BjKY-D0; Wed, 21 Sep 2022 18:31:29 +0100 Date: Wed, 21 Sep 2022 18:31:28 +0100 Message-ID: <87mtask51r.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: Catalin Marinas , Will Deacon , Zhang Lei , James Morse , Alexandru Elisei , Andre Przywara , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 1/7] KVM: arm64: Discard any SVE state when entering KVM guests In-Reply-To: References: <20220815225529.930315-1-broonie@kernel.org> <20220815225529.930315-2-broonie@kernel.org> <87zgeuj8ry.wl-maz@kernel.org> 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: broonie@kernel.org, catalin.marinas@arm.com, will@kernel.org, zhang.lei@jp.fujitsu.com, james.morse@arm.com, alexandru.elisei@arm.com, andre.przywara@arm.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org 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-20220921_103134_963720_C05A5637 X-CRM114-Status: GOOD ( 19.93 ) 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 21:21:33 +0100, Mark Brown wrote: > > [1 ] > On Tue, Sep 20, 2022 at 05:44:01PM +0100, Marc Zyngier wrote: > > Mark Brown wrote: > > > > void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) > > > { > > > BUG_ON(!current->mm); > > > - BUG_ON(test_thread_flag(TIF_SVE)); > > > + > > > + fpsimd_kvm_prepare(); > > > > Why is this *before* the check against system_supports_fpsimd()? I > > don't think the architecture allows SVE without FP, for obvious > > reasons... > > Good point, though now that I think about it I can't think of a > requirement for FP when implementing SME (there's certainly not > one for SVE). Even if the architecture was allowing this madness, KVM doesn't allow SVE if FP is not available, just like the rest of the kernel. > There's no use for that hook now though. Care to clarify? 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