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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5158C388F9 for ; Wed, 11 Nov 2020 13:29:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5971F20756 for ; Wed, 11 Nov 2020 13:29:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="LQOyM7Pk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726519AbgKKN3d (ORCPT ); Wed, 11 Nov 2020 08:29:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:60476 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725900AbgKKN3c (ORCPT ); Wed, 11 Nov 2020 08:29:32 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 79F7E206CA; Wed, 11 Nov 2020 13:29:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605101371; bh=ylTTLDgMGhQsPJGM41QX1ib3jMY1oRlkQOFl8wohlls=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LQOyM7PkxvpiYnD3r6xnWlmHvX0F0NhA8zzxDBs0TxhOmTjWZbcTycsjIfAAsvLUx U/Vqm/+0M/PlXBPlSSu31FqiCseSlSMtrm5W/kcxxpGntOMRNIvbXTDrQRiewNgHLb 2b68uft0I0UJKxxucNiks+kjPAjXb6+gvVNwD900= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kcqBl-009lwE-4n; Wed, 11 Nov 2020 13:29:29 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 11 Nov 2020 13:29:29 +0000 From: Marc Zyngier To: David Brazdil Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, James Morse , Julien Thierry , Suzuki K Poulose , Catalin Marinas , Will Deacon , Dennis Zhou , Tejun Heo , Christoph Lameter , Mark Rutland , Lorenzo Pieralisi , Quentin Perret , Andrew Scull , Andrew Walbran , kernel-team@android.com Subject: Re: [PATCH v1 07/24] kvm: arm64: Create nVHE copy of cpu_logical_map In-Reply-To: <20201111130321.qalrzfabdonrwvsz@google.com> References: <20201109113233.9012-1-dbrazdil@google.com> <20201109113233.9012-8-dbrazdil@google.com> <20201111130321.qalrzfabdonrwvsz@google.com> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <15a580e6ac06294ead8859fba8f51deb@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: dbrazdil@google.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, dennis@kernel.org, tj@kernel.org, cl@linux.com, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, qperret@google.com, ascull@google.com, qwandor@google.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-11-11 13:03, David Brazdil wrote: >> > +/* >> > + * nVHE copy of data structures tracking available CPU cores. >> > + * Only entries for CPUs that were online at KVM init are populated. >> > + * Other CPUs should not be allowed to boot because their features were >> > + * not checked against the finalized system capabilities. >> > + */ >> > +u64 __ro_after_init __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] >> > = INVALID_HWID }; >> >> I'm not sure what __ro_after_init means once we get S2 isolation. > > It is stretching the definition of 'init' a bit, I know, but I don't > see what > your worry is about S2? The intention is to mark this read-only for > .hyp.text > at runtime. With S2, the host won't be able to write to it after KVM > init. > Obviously that's currently not the case. More importantly, EL2 can write to it at any time, which is the bit I'm worried about, as it makes the annotation misleading. > One thing we might change in the future is marking it RW for some > initial > setup in a HVC handler, then marking it RO for the rest of uptime. That'd be a desirable outcome, and it would be consistent with the rest of the kernel. > >> >> > + >> > +u64 cpu_logical_map(int cpu) >> >> nit: is there any reason why "cpu" cannot be unsigned? The thought >> of a negative CPU number makes me shiver... > > Same here. That's how it's defined in kernel proper, so I went with > that. I'm happy to deviate from the kernel (give the function a different name if this clashes with existing include files). We can also fix the rest of the kernel (I've just written the trivial patch). >> >> > +{ >> > + if (cpu < 0 || cpu >= ARRAY_SIZE(__cpu_logical_map)) >> > + hyp_panic(); >> > + >> > + return __cpu_logical_map[cpu]; >> > +} >> > + >> > unsigned long __hyp_per_cpu_offset(unsigned int cpu) >> > { >> > unsigned long *cpu_base_array; >> >> Overall, this patch would make more sense closer it its use case >> (in patch 19). I also don't understand why this lives in percpu.c... > > I didn't think it called for adding another C file for this. How about > we > rename this file to smp.c? Would that make sense for both? Make that hyp-smp.c, please! M. -- Jazz is not dead. It just smells funny... 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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4B1AC388F9 for ; Wed, 11 Nov 2020 13:29:37 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id E49A0206CA for ; Wed, 11 Nov 2020 13:29:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="LQOyM7Pk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E49A0206CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; 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Wed, 11 Nov 2020 13:29:29 +0000 MIME-Version: 1.0 Date: Wed, 11 Nov 2020 13:29:29 +0000 From: Marc Zyngier To: David Brazdil Subject: Re: [PATCH v1 07/24] kvm: arm64: Create nVHE copy of cpu_logical_map In-Reply-To: <20201111130321.qalrzfabdonrwvsz@google.com> References: <20201109113233.9012-1-dbrazdil@google.com> <20201109113233.9012-8-dbrazdil@google.com> <20201111130321.qalrzfabdonrwvsz@google.com> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <15a580e6ac06294ead8859fba8f51deb@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: dbrazdil@google.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, dennis@kernel.org, tj@kernel.org, cl@linux.com, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, qperret@google.com, ascull@google.com, qwandor@google.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kernel-team@android.com, Lorenzo Pieralisi , Andrew Walbran , Catalin Marinas , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Tejun Heo , Dennis Zhou , Christoph Lameter , Will Deacon , kvmarm@lists.cs.columbia.edu X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 2020-11-11 13:03, David Brazdil wrote: >> > +/* >> > + * nVHE copy of data structures tracking available CPU cores. >> > + * Only entries for CPUs that were online at KVM init are populated. >> > + * Other CPUs should not be allowed to boot because their features were >> > + * not checked against the finalized system capabilities. >> > + */ >> > +u64 __ro_after_init __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] >> > = INVALID_HWID }; >> >> I'm not sure what __ro_after_init means once we get S2 isolation. > > It is stretching the definition of 'init' a bit, I know, but I don't > see what > your worry is about S2? The intention is to mark this read-only for > .hyp.text > at runtime. With S2, the host won't be able to write to it after KVM > init. > Obviously that's currently not the case. More importantly, EL2 can write to it at any time, which is the bit I'm worried about, as it makes the annotation misleading. > One thing we might change in the future is marking it RW for some > initial > setup in a HVC handler, then marking it RO for the rest of uptime. That'd be a desirable outcome, and it would be consistent with the rest of the kernel. > >> >> > + >> > +u64 cpu_logical_map(int cpu) >> >> nit: is there any reason why "cpu" cannot be unsigned? The thought >> of a negative CPU number makes me shiver... > > Same here. That's how it's defined in kernel proper, so I went with > that. I'm happy to deviate from the kernel (give the function a different name if this clashes with existing include files). We can also fix the rest of the kernel (I've just written the trivial patch). >> >> > +{ >> > + if (cpu < 0 || cpu >= ARRAY_SIZE(__cpu_logical_map)) >> > + hyp_panic(); >> > + >> > + return __cpu_logical_map[cpu]; >> > +} >> > + >> > unsigned long __hyp_per_cpu_offset(unsigned int cpu) >> > { >> > unsigned long *cpu_base_array; >> >> Overall, this patch would make more sense closer it its use case >> (in patch 19). I also don't understand why this lives in percpu.c... > > I didn't think it called for adding another C file for this. How about > we > rename this file to smp.c? Would that make sense for both? Make that hyp-smp.c, please! M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8778C5517A for ; Wed, 11 Nov 2020 13:29:59 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 514D6206CA for ; Wed, 11 Nov 2020 13:29:59 +0000 (UTC) Authentication-Results: mail.kernel.org; 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a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605101371; bh=ylTTLDgMGhQsPJGM41QX1ib3jMY1oRlkQOFl8wohlls=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LQOyM7PkxvpiYnD3r6xnWlmHvX0F0NhA8zzxDBs0TxhOmTjWZbcTycsjIfAAsvLUx U/Vqm/+0M/PlXBPlSSu31FqiCseSlSMtrm5W/kcxxpGntOMRNIvbXTDrQRiewNgHLb 2b68uft0I0UJKxxucNiks+kjPAjXb6+gvVNwD900= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kcqBl-009lwE-4n; Wed, 11 Nov 2020 13:29:29 +0000 MIME-Version: 1.0 Date: Wed, 11 Nov 2020 13:29:29 +0000 From: Marc Zyngier To: David Brazdil Subject: Re: [PATCH v1 07/24] kvm: arm64: Create nVHE copy of cpu_logical_map In-Reply-To: <20201111130321.qalrzfabdonrwvsz@google.com> References: <20201109113233.9012-1-dbrazdil@google.com> <20201109113233.9012-8-dbrazdil@google.com> <20201111130321.qalrzfabdonrwvsz@google.com> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <15a580e6ac06294ead8859fba8f51deb@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: dbrazdil@google.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, dennis@kernel.org, tj@kernel.org, cl@linux.com, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, qperret@google.com, ascull@google.com, qwandor@google.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201111_082933_078757_076C6165 X-CRM114-Status: GOOD ( 27.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , kernel-team@android.com, Lorenzo Pieralisi , Andrew Walbran , Suzuki K Poulose , Catalin Marinas , Quentin Perret , linux-kernel@vger.kernel.org, James Morse , linux-arm-kernel@lists.infradead.org, Tejun Heo , Dennis Zhou , Christoph Lameter , Will Deacon , kvmarm@lists.cs.columbia.edu, Julien Thierry , Andrew Scull Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020-11-11 13:03, David Brazdil wrote: >> > +/* >> > + * nVHE copy of data structures tracking available CPU cores. >> > + * Only entries for CPUs that were online at KVM init are populated. >> > + * Other CPUs should not be allowed to boot because their features were >> > + * not checked against the finalized system capabilities. >> > + */ >> > +u64 __ro_after_init __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] >> > = INVALID_HWID }; >> >> I'm not sure what __ro_after_init means once we get S2 isolation. > > It is stretching the definition of 'init' a bit, I know, but I don't > see what > your worry is about S2? The intention is to mark this read-only for > .hyp.text > at runtime. With S2, the host won't be able to write to it after KVM > init. > Obviously that's currently not the case. More importantly, EL2 can write to it at any time, which is the bit I'm worried about, as it makes the annotation misleading. > One thing we might change in the future is marking it RW for some > initial > setup in a HVC handler, then marking it RO for the rest of uptime. That'd be a desirable outcome, and it would be consistent with the rest of the kernel. > >> >> > + >> > +u64 cpu_logical_map(int cpu) >> >> nit: is there any reason why "cpu" cannot be unsigned? The thought >> of a negative CPU number makes me shiver... > > Same here. That's how it's defined in kernel proper, so I went with > that. I'm happy to deviate from the kernel (give the function a different name if this clashes with existing include files). We can also fix the rest of the kernel (I've just written the trivial patch). >> >> > +{ >> > + if (cpu < 0 || cpu >= ARRAY_SIZE(__cpu_logical_map)) >> > + hyp_panic(); >> > + >> > + return __cpu_logical_map[cpu]; >> > +} >> > + >> > unsigned long __hyp_per_cpu_offset(unsigned int cpu) >> > { >> > unsigned long *cpu_base_array; >> >> Overall, this patch would make more sense closer it its use case >> (in patch 19). I also don't understand why this lives in percpu.c... > > I didn't think it called for adding another C file for this. How about > we > rename this file to smp.c? Would that make sense for both? Make that hyp-smp.c, please! M. -- Jazz is not dead. It just smells funny... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel