From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B9350D505 for ; Wed, 2 Aug 2023 15:55:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 371B5C433C8; Wed, 2 Aug 2023 15:55:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690991713; bh=vmS3y3vEprt4Ee9EVdT/KBotedRLV0L1wK1C8giiJQ0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=WeiXGksNCeqBY0D4Z/8Ow3J9XqjC9OJyQu+88uQz8TQaiKoIgPzO9Yl9TRNFTlF3D N39NOOXy/Mz33yVrblUjCuLOvbkllNtHrbplC8Lqq3XEZb+5b6hwCMns6zjmiGDiR5 WyKju8MvL8RFMV0pD03r+FySvZn1XdniQk0Eq3w2KYJ+neD3VaPmcPNIxN2Y2gg+sv DUsm6xoKz5G2XuJa48wmKk8Acu4wfo23otwQde0jhhtejTCMbDPpc0JiEX4uvF0xoL oztN3yS/UAXRXhwX7BD0euPVgBUKmEnA+m7EZc5otPguhtVvE1+tJsa8wHuWBmvo03 IzWfXQNHWVpaQ== Received: from [104.132.1.99] (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 1qREBq-001PtL-B3; Wed, 02 Aug 2023 16:55:10 +0100 Date: Wed, 02 Aug 2023 16:55:05 +0100 Message-ID: <877cqdqw12.wl-maz@kernel.org> From: Marc Zyngier To: Sean Christopherson Cc: Raghavendra Rao Ananta , Oliver Upton , James Morse , Suzuki K Poulose , Paolo Bonzini , Huacai Chen , Zenghui Yu , Anup Patel , Atish Patra , Jing Zhang , Reiji Watanabe , Colton Lewis , David Matlack , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH v7 02/12] KVM: arm64: Use kvm_arch_flush_remote_tlbs() In-Reply-To: References: <20230722022251.3446223-1-rananta@google.com> <20230722022251.3446223-3-rananta@google.com> <87tttpr6qy.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/28.2 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 104.132.1.99 X-SA-Exim-Rcpt-To: seanjc@google.com, rananta@google.com, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, pbonzini@redhat.com, chenhuacai@kernel.org, yuzenghui@huawei.com, anup@brainfault.org, atishp@atishpatra.org, jingzhangos@google.com, reijiw@google.com, coltonlewis@google.com, dmatlack@google.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Mon, 31 Jul 2023 22:50:07 +0100, Sean Christopherson wrote: > > On Thu, Jul 27, 2023, Marc Zyngier wrote: > > On Sat, 22 Jul 2023 03:22:41 +0100, > > Raghavendra Rao Ananta wrote: > > > > > > Stop depending on CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL and opt to > > > standardize on kvm_arch_flush_remote_tlbs() since it avoids > > > duplicating the generic TLB stats across architectures that implement > > > their own remote TLB flush. > > > > > > This adds an extra function call to the ARM64 kvm_flush_remote_tlbs() > > > path, but that is a small cost in comparison to flushing remote TLBs. > > > > Well, there is no such thing as a "remote TLB" anyway. We either have > > a non-shareable or inner-shareable invalidation. The notion of remote > > would imply that we track who potentially has a TLB, which we > > obviously don't. > > Maybe kvm_arch_flush_vm_tlbs()? The "remote" part is misleading even on x86 when > running on Hyper-V, as the flush may be done via a single hypercall and by kicking > "remote" vCPUs. Yup, this would be much better. Thanks, M. -- Without deviation from the norm, progress is not possible.