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 65FB9CA0FF2 for ; Tue, 26 Aug 2025 17:01:08 +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=IHfTHKaGp6xIm5G8a5gz7P2rf0z12V3FHXth6rk6Xuk=; b=JeIVDkukl2zD2b GTs4nHId8YOo7Z8ZVeZmt/ZZcUxw7DNwsj2cvmQ5aSVNHzK2LjNmDbNLTpnvj+sRFYGt7DFWfN/oB NyDui5OogufOnZN4yumZuYy/k4r3pS1OhW+i4g7c4j0+yz0xJ1Rvi9hMAUSm357JT4ymUXdtA4mk/ 447t2OLeehSKLdk01q5MsIIJlREideBsAqs5Agm/opstl99irGACrUfrVkgUAu1BzeIRQNfCcQzjM McQ3O4G70Sk3piSuGH5MZdVimP5UoBpsO+2WMdNsilCXNKqtvWTNj3aHLhTFLk9WKN6o2B4Jyplgr xq1laW31QICopnDfjZNw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uqx2Y-0000000Ci1M-29ey; Tue, 26 Aug 2025 17:00:58 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uqwzp-0000000ChNV-39Ms; Tue, 26 Aug 2025 16:58:09 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=B1Ra0sIa1ZhdeCCWkbFdTe10sKp2xTKc4kpjbQJ+L0o=; b=O2hOXDu1uzbwlX7OANF+iGx/R+ 6UoXejCDibkCsBP0Sufh3Cb3m2ROKpT0+iygB0+J2CFV6fsEcSakCSOSpcjcst5wqBNZ9Rl7SvzIa Pp8Cm8v4K61eCclnm95hf4TwyzFqt3VNXXKASCFdrpUfQBmIKmHmZMWxCZeMODzT0/ZSx1BXyXevy LBYUvUvp3c2Jv1v+1UkRNjfGE9F5GZHLGzke7MyECyGMET1vTEOJH00LPKwLlO5Nr2QYb4X85ZH/L 8C93B3Ay1P9C54Em9H9JVOShPXXyBlOSfgO6zM9rI1vKDiYjnkTX7V5taI1ycLtBX9hzcD4QAYzEJ 9DcRBDbw==; Received: from sea.source.kernel.org ([172.234.252.31]) by desiato.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uqwzm-00000002HDR-20kM; Tue, 26 Aug 2025 16:58:08 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 828AA44427; Tue, 26 Aug 2025 16:58:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C82A7C4CEF1; Tue, 26 Aug 2025 16:58:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756227482; bh=fnUtXDAxJfdbxKoWIvjZ0YEMsdquajfs3Wt0vqohrgU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fuvpJ+uRtRM9fzHvRv14jD9ZQo0Z+Ik1UILyoPgPF2jz8dNyPROaEFVvlvQAaXz4X ttXYaAtJGkub4HtTxq/BEINhmPDYT0kc4MO9Pt7hSTntGG0uTTAcFEzDYKdGxtFeT2 qkjkQ9Njb/UFnPIIvb1+17UQA9vp2juzNUYGm3uywq3v8NTkaS1OlNFYQ09AI39lpx YQaZvSP4SUfRf4YlPPa54Y1tNy/wsF7ZVJVKqynCB7t8JfsAtW1Xvl7gh2NjEvVbqY byeS9jwZXrmVRhx6StAaC2vlVi6HX3Ox4JExT2RQEj9zwDNL3tioAysr1mHqOoXhAg 8DUjtPx04KNjg== Date: Tue, 26 Aug 2025 16:58:00 +0000 From: Wei Liu To: Sean Christopherson Cc: Nuno Das Neves , Marc Zyngier , Oliver Upton , Catalin Marinas , Will Deacon , Tianrui Zhao , Bibo Mao , Huacai Chen , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Peter Zijlstra , Andy Lutomirski , "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-hyperv@vger.kernel.org, rcu@vger.kernel.org Subject: Re: [PATCH 0/5] Drivers: hv: Fix NEED_RESCHED_LAZY and use common APIs Message-ID: References: <20250825200622.3759571-1-seanjc@google.com> <3188ca61-2591-4576-9777-1671689b7235@linux.microsoft.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250826_175806_966277_7C8F639B X-CRM114-Status: GOOD ( 30.26 ) 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, Aug 25, 2025 at 05:27:16PM -0700, Sean Christopherson wrote: > On Mon, Aug 25, 2025, Nuno Das Neves wrote: > > On 8/25/2025 1:06 PM, Sean Christopherson wrote: > > > Fix a bug where MSHV root partitions don't honor NEED_RESCHED_LAZY, and then > > > deduplicate the TIF related MSHV code by turning the "kvm" entry APIs into > > > more generic "virt" APIs (which ideally would have been done when MSHV root > > > support was added). > > > > > > Assuming all is well, maybe this could go through the tip tree? > > > > > > The Hyper-V stuff and non-x86 architectures are compile-tested only. > > > > > > > Thanks Sean, I can test the root partition changes. > > > > A similar change will be needed in mshv_vtl_main.c since it also calls > > mshv_do_pre_guest_mode_work() (hence the "common" in mshv_common.c). > > Oof, more dependencies. I suppose the easiest thing would be to send a series > against > > git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git queue > > and then route everything through there? Our fixes branch is on 6.17-rc1. You can use it as a base if you want to. > > Alternatively, frontload the MSHV fixes (which I'll do regardless) and take those > through hyperv and the rest through the tip tree? That seems like an absurd > amount of juggling though, especially if we want to get the cleanups into 6.18. > And if none of these lands, it's MSHV that'll suffer the most, so betting it all > on the hyperv tree doesn't seem terrible. > I'm happy to do it however the community sees fit. > > Also, is it possible to make all the mshv driver changes in a single patch? > > It's certainly possible, but I'd prefer not do to that. > > > It seems like it would be cleaner than refactoring it in patches 1 & 2 and > > then deleting all the refactored code in patch 5. > > Only if you don't care about backporting fixes, bisection, or maintaining code. > > E.g. if checking NEED_RESCHED_LAZY somehow causes issues, it would be really nice > for that to bisect to exactly that patch, not a patch that also switches to a > completely different set of APIs. > > And if someone is wants the fixes in a pre-6.18 kernel, they don't need to > backport all of the KVM and entry code changes just to get the fix. +1 on this. Thanks, Wei > > As for the maintenance headache, see above. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv