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 CDEAAECAAA1 for ; Mon, 24 Oct 2022 09:27:13 +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=TXCCFjhgAyJ7p/2w8JJ0+3GnUmEeSfGCTocTPdYMi6w=; b=F97IqzFARG/uRc Ge9XoIz/sIB+1imWc2oxdjaW7Q0lKI3TQ5F3mgBT1+vgWlPDPmmuhdlj38nq4lDV0PLHs0rpooeim KHY8Q8uHWCqq+a+DNlB6/mYQy2QAWG8qu/n6FKDP/ArbGdAy76RWbid/F1HLOkBReHgZx6I+6fJHN hM0EnWu6WSdvC/kPoDx6xwa0M8uOzQUkaSi938m+eZRUFrTnmXq/NOyvXSX/pkrrDZEyr/gtfMqWC cI4HuD4nzpnZFSITlqdHzexSy5LCcz37h7bziNuFeQa+Cu9jMhqr0ul7wlednwHd1QtEIK1KXYnMS cnqpkp/xLbe0RfYPFSEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1omtjb-000OfU-KX; Mon, 24 Oct 2022 09:27:03 +0000 Received: from esa.microchip.iphmx.com ([68.232.153.233]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1omtjX-000OeA-9P for linux-riscv@lists.infradead.org; Mon, 24 Oct 2022 09:27:01 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1666603618; x=1698139618; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=vX0ZrGoOesTgoaEnsAdldsG4YphzsUDAEg+i05TK0CQ=; b=L7mBsSxF9L8AKPswD51eYk4GeCVoLbpX7Mkfc8fjf2Rpj5LDzWCGxNKc X59hfRaO4nGV4cHYsYHpYhr8JNU/dBcHNsZM9BE2x7KTPVqDFpWqxB1OM 0JaJllr84IOyKJbqQt689w8oA8b5wsX/3TxOiuGEry7ieYXr5GXjBxIlJ JaxXVjy1OooE7v1oyOTGP5NNA1Myc+lNokx7rIBcEMKKEQ3aN+3kQn1ff VBsvALx7sDkRx7WyEA1PqkqOFNXlJKOzT3n5nHNztKI7pwIumVyIPt+l2 4LQgPeR4ZLrIvWYVmXvD5MxON2Pbcmla5vJkxSKOs9TeGmLdKJbHt0jpg g==; X-IronPort-AV: E=Sophos;i="5.95,207,1661842800"; d="scan'208";a="186099133" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa3.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 24 Oct 2022 02:26:55 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.85.143) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12; Mon, 24 Oct 2022 02:26:54 -0700 Received: from wendy (10.10.115.15) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12 via Frontend Transport; Mon, 24 Oct 2022 02:26:53 -0700 Date: Mon, 24 Oct 2022 10:26:36 +0100 From: Conor Dooley To: Andrew Jones CC: Conor Dooley , , Palmer Dabbelt , Paul Walmsley , Albert Ou , Heiko Stuebner , Anup Patel , Atish Patra Subject: Re: [PATCH 3/3] RISC-V: Ensure Zicbom has a valid block size Message-ID: References: <20221021105905.206385-1-ajones@ventanamicro.com> <20221021105905.206385-4-ajones@ventanamicro.com> <20221024070935.ff62bcjl6z7i4flh@kamzik> <20221024083522.fgwej6saqhbvumfj@kamzik> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221024083522.fgwej6saqhbvumfj@kamzik> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221024_022659_395031_2A54B312 X-CRM114-Status: GOOD ( 24.40 ) X-BeenThere: linux-riscv@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-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Oct 24, 2022 at 10:35:22AM +0200, Andrew Jones wrote: > On Mon, Oct 24, 2022 at 09:17:50AM +0100, Conor Dooley wrote: > > My initial thought here was along the lines of "why care about the > > issues when it's not enabled", but I went to get some caffeine before > > replying and had a change of heart. > > IMO, it'd be good to tell people that their DT doesn't describe their > > hardware properly when it's gone wrong in a way that we cannot really > > spot via dtbs_check etc. I'll go away and have a think about whether > > the DT checks can force cbom-block-size if zicbom is in the isa string, > > but I'm not sure if that sort of conditional is checkable. > > If either of these error cases are hit (regardless of whether you set > > CONFIG_RISCV_ISA_ZICBOM) then it'd cause issues for KVM right? That > > would imply printing unconditionally to me. > > Yes and no. KVM won't have any issues as it won't see Zicbom in the ISA > bitmap and therefore won't consider offering it to guests. However, it > could have offered it to guests, if only the DT was fixed, so I agree, > it's best to unconditionally complain when we see something wrong. Yeah, that's pretty much what I was getting at. By "KVM having issues" I meant that without disabling Zicbom, as your patch does, KVM would carry on & offer Zicbom with the "bad" cbom block size to guests. Following that line of thought, we'd then want to disable Zicbom & complain no matter the state of the kconfig symbol so that there'd be info there for the folks running a non-Zicbom kernel but trying to use Zicbom in their guest. > > > The level at which to > > actually emit that is beyond the scope of what I care about though ;) > > This stackoverflow.com thread indicates I should use 'error'. > https://stackoverflow.com/questions/2031163/when-to-use-the-different-log-levels Yeah, on the basis of that thread error does seem appropriate. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv