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 8F4FCC433F5 for ; Tue, 22 Feb 2022 12:54:38 +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=1yyVIPcI6UgoabaJMsfLyu5DnLP6hSPKjmL5F+3RKgo=; b=U5g7TQFZ6d/D5F JgVPZPVzeN+MBZedYrJsTx1s1kigxDmvl9b/corEs3sBW8CraSvOg/RPGF+/Kdls5nebHKmxWdwDm XN77ccjJ3t7tLw9ELCnZp6INNQ3xFkQWU7vmx4zng+/ea5hNtJNaZrvOa1nnkNPJXqzJO7o5IzYVv o97sDW7LjMU/K1PwBIJH58G9Rcmli8OWpLAB34h7B4aVRWELyKtdl+VZLm0L0FxpFBzo61ln5tcYF uffJQBsnTdLj9F155R5cBNfHJid1t3DYVz7PXLfxomh9mhL0AW9HplbhbVv9tV5VLYDHExpl5mBbd ZRJRrdVAbLOOmqjWKdiA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nMUfV-009bAO-4b; Tue, 22 Feb 2022 12:53:25 +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 1nMUfR-009b9L-N4 for linux-arm-kernel@lists.infradead.org; Tue, 22 Feb 2022 12:53:23 +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 85968B819B6; Tue, 22 Feb 2022 12:53:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 248D4C340E8; Tue, 22 Feb 2022 12:53:14 +0000 (UTC) Date: Tue, 22 Feb 2022 12:53:11 +0000 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , Marc Zyngier , Shuah Khan , Shuah Khan , Alan Hayward , Luis Machado , Salil Akerkar , Basant Kumar Dwivedi , Szabolcs Nagy , James Morse , Alexandru Elisei , Suzuki K Poulose , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: Re: [PATCH v11 16/40] arm64/sme: Implement streaming SVE context switching Message-ID: References: <20220207152109.197566-1-broonie@kernel.org> <20220207152109.197566-17-broonie@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220207152109.197566-17-broonie@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220222_045321_942848_34F360A0 X-CRM114-Status: GOOD ( 13.12 ) 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 Mon, Feb 07, 2022 at 03:20:45PM +0000, Mark Brown wrote: > When in streaming mode we need to save and restore the streaming mode > SVE register state rather than the regular SVE register state. This uses > the streaming mode vector length and omits FFR but is otherwise identical, > if TIF_SVE is enabled when we are in streaming mode then streaming mode > takes precedence. > > This does not handle use of streaming SVE state with KVM, ptrace or > signals. This will be updated in further patches. I think I get this but a state diagram somewhere would help ;). IIUC you don't disable SM on a context switch, you just leave it in place until a task_fpsimd_load(). It shouldn't be a problem as kernel_neon_begin() disables it anyway. Reviewed-by: Catalin Marinas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel