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=-15.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 877B6C433DB for ; Wed, 17 Mar 2021 17:20:20 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id EDD9B64EED for ; Wed, 17 Mar 2021 17:20:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EDD9B64EED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 861A14B686; Wed, 17 Mar 2021 13:20:19 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id suxTrep339RT; Wed, 17 Mar 2021 13:20:18 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 834284B693; Wed, 17 Mar 2021 13:20:18 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 64D914B686 for ; Wed, 17 Mar 2021 13:20:17 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9kumYTlNObM7 for ; Wed, 17 Mar 2021 13:20:16 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 6EC9B4B679 for ; Wed, 17 Mar 2021 13:20:16 -0400 (EDT) Received: by mail.kernel.org (Postfix) with ESMTPSA id D82C864E0F; Wed, 17 Mar 2021 17:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616001613; bh=jHjxIb9xISuowelZ+isObXqoEf9PZ5lTJzVIllP5qAE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nLFMglnQaIuWYkZPSMGTbsmf+DeHb0DnHRJhErUh7EASk+XRM9Usqcys1twY/vHzk ZVmNKxWXCXRR6EC1WxFWVuLMDj7i1h7K9pbrpsvAbcZisyv0vEk1EHObp2cotk/UQL 52saNkq78Ud8/R4mwHBJQoFz1ADBSBCyoQmG4UMaSUnUZHRa3DfqGH6Lf7wMlKeTe5 rtFnn1edg17Yg8hZ+L1WGFBNbQtT1xQj1S9EEeySmlytLYDMcaEeOySd+U3d+04OFt LkmxDbetUGZWciAjtQva0LulHdJG6m7zC/WPNNG3ZjR/JC4+qW+/zsKm2RTwpq21nv OA5vRw9lTC2Gw== Date: Wed, 17 Mar 2021 17:20:08 +0000 From: Will Deacon To: Marc Zyngier Subject: Re: [PATCH 07/10] KVM: arm64: Save guest's ZCR_EL1 before saving the FPSIMD state Message-ID: <20210317172008.GB5640@willie-the-truck> References: <20210316101312.102925-1-maz@kernel.org> <20210316101312.102925-8-maz@kernel.org> <20210317171738.GA5640@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210317171738.GA5640@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: kvm@vger.kernel.org, Catalin Marinas , kvmarm@lists.cs.columbia.edu, broonie@kernel.org, kernel-team@android.com, dave.martin@arm.com, linux-arm-kernel@lists.infradead.org, daniel.kiss@arm.com 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Wed, Mar 17, 2021 at 05:17:38PM +0000, Will Deacon wrote: > On Tue, Mar 16, 2021 at 10:13:09AM +0000, Marc Zyngier wrote: > > Make sure the guest's ZCR_EL1 is saved before we save/flush the > > state. This will be useful in later patches. > > > > Signed-off-by: Marc Zyngier > > --- > > arch/arm64/kvm/fpsimd.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c > > index 84afca5ed6f2..b5f95abd23f5 100644 > > --- a/arch/arm64/kvm/fpsimd.c > > +++ b/arch/arm64/kvm/fpsimd.c > > @@ -121,10 +121,10 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) > > local_irq_save(flags); > > > > if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { > > - fpsimd_save_and_flush_cpu_state(); > > - > > if (guest_has_sve) > > __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); > > + > > + fpsimd_save_and_flush_cpu_state(); > > I _think_ fpsimd_save_and_flush_cpu_state() contains a RDVL instruction > to get at the vector length for sve_get_vl(), and this ends up reading from > ZCR_EL1. So I'm not sure it's save to move it like this. Duh, we're not changing the register here, but just saving it off. So it's fine: Acked-by: Will Deacon Will _______________________________________________ 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=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 3E733C433E0 for ; Wed, 17 Mar 2021 17:21:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02F0364E61 for ; Wed, 17 Mar 2021 17:21:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232120AbhCQRVR (ORCPT ); Wed, 17 Mar 2021 13:21:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:47880 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231682AbhCQRUO (ORCPT ); Wed, 17 Mar 2021 13:20:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D82C864E0F; Wed, 17 Mar 2021 17:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616001613; bh=jHjxIb9xISuowelZ+isObXqoEf9PZ5lTJzVIllP5qAE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nLFMglnQaIuWYkZPSMGTbsmf+DeHb0DnHRJhErUh7EASk+XRM9Usqcys1twY/vHzk ZVmNKxWXCXRR6EC1WxFWVuLMDj7i1h7K9pbrpsvAbcZisyv0vEk1EHObp2cotk/UQL 52saNkq78Ud8/R4mwHBJQoFz1ADBSBCyoQmG4UMaSUnUZHRa3DfqGH6Lf7wMlKeTe5 rtFnn1edg17Yg8hZ+L1WGFBNbQtT1xQj1S9EEeySmlytLYDMcaEeOySd+U3d+04OFt LkmxDbetUGZWciAjtQva0LulHdJG6m7zC/WPNNG3ZjR/JC4+qW+/zsKm2RTwpq21nv OA5vRw9lTC2Gw== Date: Wed, 17 Mar 2021 17:20:08 +0000 From: Will Deacon To: Marc Zyngier Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, dave.martin@arm.com, daniel.kiss@arm.com, Catalin Marinas , James Morse , Julien Thierry , Suzuki K Poulose , broonie@kernel.org, kernel-team@android.com Subject: Re: [PATCH 07/10] KVM: arm64: Save guest's ZCR_EL1 before saving the FPSIMD state Message-ID: <20210317172008.GB5640@willie-the-truck> References: <20210316101312.102925-1-maz@kernel.org> <20210316101312.102925-8-maz@kernel.org> <20210317171738.GA5640@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210317171738.GA5640@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Mar 17, 2021 at 05:17:38PM +0000, Will Deacon wrote: > On Tue, Mar 16, 2021 at 10:13:09AM +0000, Marc Zyngier wrote: > > Make sure the guest's ZCR_EL1 is saved before we save/flush the > > state. This will be useful in later patches. > > > > Signed-off-by: Marc Zyngier > > --- > > arch/arm64/kvm/fpsimd.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c > > index 84afca5ed6f2..b5f95abd23f5 100644 > > --- a/arch/arm64/kvm/fpsimd.c > > +++ b/arch/arm64/kvm/fpsimd.c > > @@ -121,10 +121,10 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) > > local_irq_save(flags); > > > > if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { > > - fpsimd_save_and_flush_cpu_state(); > > - > > if (guest_has_sve) > > __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); > > + > > + fpsimd_save_and_flush_cpu_state(); > > I _think_ fpsimd_save_and_flush_cpu_state() contains a RDVL instruction > to get at the vector length for sve_get_vl(), and this ends up reading from > ZCR_EL1. So I'm not sure it's save to move it like this. Duh, we're not changing the register here, but just saving it off. So it's fine: Acked-by: Will Deacon Will 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=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 01CD6C433DB for ; Wed, 17 Mar 2021 17:23:09 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 7B63364E0F for ; Wed, 17 Mar 2021 17:23:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B63364E0F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; 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=4zUuxxR6ebOrFDDbmkd9AV1SOmkN0jOOTogpKCa7zyY=; b=Km74MP6LqfmWvgrfi9vchNQ4m xy6AN8mIvE8JHOqcvI+wetMEUL9YGX92Cr6CbtAETjoUS7N8qutKhAb95zVK4sLZMGGL/kkUmNIlk RqWfk/ErfYutGv80eCvA+n7sFS64ACrHnAWbrn0pQPs6mhW53d/2YRAH4EZ1bGp9jmsqa7c59tbtY mkg7xICTtv5j3wVjQd15Faq7b1aAmhTGD0geVOmZFK85s0U709/jSAOEMZ3gmRjer1tZHiy3JgWfK PTUAvYzUuRZwXJWUQ0VHCU/UNGE3N09l8AN4tPTrnYvenMWELeqmEj9wd1pH/9rNs7razWmOEIOn3 k4h+haigQ==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lMZqF-003cXB-A7; Wed, 17 Mar 2021 17:20:19 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lMZqB-003cWU-D0 for linux-arm-kernel@lists.infradead.org; Wed, 17 Mar 2021 17:20:17 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id D82C864E0F; Wed, 17 Mar 2021 17:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616001613; bh=jHjxIb9xISuowelZ+isObXqoEf9PZ5lTJzVIllP5qAE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nLFMglnQaIuWYkZPSMGTbsmf+DeHb0DnHRJhErUh7EASk+XRM9Usqcys1twY/vHzk ZVmNKxWXCXRR6EC1WxFWVuLMDj7i1h7K9pbrpsvAbcZisyv0vEk1EHObp2cotk/UQL 52saNkq78Ud8/R4mwHBJQoFz1ADBSBCyoQmG4UMaSUnUZHRa3DfqGH6Lf7wMlKeTe5 rtFnn1edg17Yg8hZ+L1WGFBNbQtT1xQj1S9EEeySmlytLYDMcaEeOySd+U3d+04OFt LkmxDbetUGZWciAjtQva0LulHdJG6m7zC/WPNNG3ZjR/JC4+qW+/zsKm2RTwpq21nv OA5vRw9lTC2Gw== Date: Wed, 17 Mar 2021 17:20:08 +0000 From: Will Deacon To: Marc Zyngier Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, dave.martin@arm.com, daniel.kiss@arm.com, Catalin Marinas , James Morse , Julien Thierry , Suzuki K Poulose , broonie@kernel.org, kernel-team@android.com Subject: Re: [PATCH 07/10] KVM: arm64: Save guest's ZCR_EL1 before saving the FPSIMD state Message-ID: <20210317172008.GB5640@willie-the-truck> References: <20210316101312.102925-1-maz@kernel.org> <20210316101312.102925-8-maz@kernel.org> <20210317171738.GA5640@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210317171738.GA5640@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210317_172015_697422_BEDB1913 X-CRM114-Status: GOOD ( 18.24 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Mar 17, 2021 at 05:17:38PM +0000, Will Deacon wrote: > On Tue, Mar 16, 2021 at 10:13:09AM +0000, Marc Zyngier wrote: > > Make sure the guest's ZCR_EL1 is saved before we save/flush the > > state. This will be useful in later patches. > > > > Signed-off-by: Marc Zyngier > > --- > > arch/arm64/kvm/fpsimd.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c > > index 84afca5ed6f2..b5f95abd23f5 100644 > > --- a/arch/arm64/kvm/fpsimd.c > > +++ b/arch/arm64/kvm/fpsimd.c > > @@ -121,10 +121,10 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) > > local_irq_save(flags); > > > > if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { > > - fpsimd_save_and_flush_cpu_state(); > > - > > if (guest_has_sve) > > __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); > > + > > + fpsimd_save_and_flush_cpu_state(); > > I _think_ fpsimd_save_and_flush_cpu_state() contains a RDVL instruction > to get at the vector length for sve_get_vl(), and this ends up reading from > ZCR_EL1. So I'm not sure it's save to move it like this. Duh, we're not changing the register here, but just saving it off. So it's fine: Acked-by: Will Deacon Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel