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 B47B41940B0; Wed, 2 Oct 2024 15:55:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727884529; cv=none; b=BFPWknSNz0C56zeMhAWndvH3DZSPm2aEK4v9QU9Dq89fdXYPOMuqhW3PQBA2cBhleMtc79U7Nb9ynC3eXlGRp2vnqce8AyMaU+1aWdqTstilldZEsEBnG6kL+ZilMt39sXE20FZ7GTxR9xuW8s7BpNVbkdG/5Z8OZ4sO1IgdRKs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727884529; c=relaxed/simple; bh=27HUeDVHXOs+OLA9bA8uKhz/MQrgdafn0/iAATWL0mM=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=BSqb7psb5hJOtY4wAztllP3xLFEOxLzysKVuyaLSvUA/xwhHrgSt4pOdG4ok2wM7w2YVsajBkzeu67SJzgQKyrGhT8equzW91kMPGRI3uS5LED/2CzApd8ej9aH+KNA/Ly8XZHkUIbOmsC+SKrfhj6GW9GSY8EyWiFBG+cA8SaQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k9RkyEgh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k9RkyEgh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79667C4CEC2; Wed, 2 Oct 2024 15:55:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727884529; bh=27HUeDVHXOs+OLA9bA8uKhz/MQrgdafn0/iAATWL0mM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=k9RkyEgh+Y/YS87nAPF1Ao6uiCfC2Ka09hloc087gdGHJXHVDYXjBmR2ceETg9ni6 deks86zaFNOb6z1/RiWcTXvOF0U/JLOW08+SpteRcOBc5nPa3btIZx+FKc8OiNN7e+ FEG/zba/f2YQ1sA2bH3Qf0Z5Uaro4RI1sXzvYN+fyrehRew3uav87f7UIuG26TbRhf SHQvJ+naVNRRTRSJjCOOekaQRb5r/ZRFkTQWCmGQOBDzHBWS9b9AJAbC35w5zYjD/x A1nX477cbgft4pfSE+Rw4NrdL8NdIF2MVohLnxdgNDdBRy1nbrrn5eOA9cIL3jvekY d3ZSOc2PuCwsA== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.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 1sw1hG-00H6P0-9r; Wed, 02 Oct 2024 16:55:26 +0100 Date: Wed, 02 Oct 2024 16:55:25 +0100 Message-ID: <86a5fm7b4i.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , David Spickett , Yury Khrustalev , Wilco Dijkstra , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v13 16/40] KVM: arm64: Manage GCS access and registers for guests In-Reply-To: <86bk0373nq.wl-maz@kernel.org> References: <20241001-arm64-gcs-v13-0-222b78d87eee@kernel.org> <20241001-arm64-gcs-v13-16-222b78d87eee@kernel.org> <86bk0373nq.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/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org 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: 185.219.108.64 X-SA-Exim-Rcpt-To: broonie@kernel.org, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, akpm@linux-foundation.org, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, arnd@arndb.de, oleg@redhat.com, ebiederm@xmission.com, shuah@kernel.org, rick.p.edgecombe@intel.com, debug@rivosinc.com, ardb@kernel.org, Szabolcs.Nagy@arm.com, kees@kernel.org, hjl.tools@gmail.com, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, fweimer@redhat.com, brauner@kernel.org, thiago.bauermann@linaro.org, ross.burton@arm.com, david.spickett@arm.com, yury.khrustalev@arm.com, wilco.dijkstra@arm.com, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@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 On Wed, 02 Oct 2024 01:24:25 +0100, Marc Zyngier wrote: > > On Tue, 01 Oct 2024 23:58:55 +0100, > Mark Brown wrote: > > > @@ -4714,6 +4735,10 @@ void kvm_calculate_traps(struct kvm_vcpu *vcpu) > > kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPOR_EL1 | > > HFGxTR_EL2_nPOR_EL0); > > > > + if (!kvm_has_gcs(kvm)) > > + kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nGCS_EL0 | > > + HFGxTR_EL2_nGCS_EL1); > > + > > Why are you still allowing the GCS instructions when GCS isn't > enabled? Scratch that, they are NOPs when GCS isn't enabled, so there shouldn't be any need for extra traps. M. -- Without deviation from the norm, progress is not possible.