From patchwork Fri May 3 12:43:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 10928591 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1D0B117E6 for ; Fri, 3 May 2019 12:46:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0B80C204FD for ; Fri, 3 May 2019 12:46:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F28DD28334; Fri, 3 May 2019 12:46:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 73908285BD for ; Fri, 3 May 2019 12:46:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9h1NgtWtcqPV1soFwTs+7M2hCikQdQOitVzWE2Q3U8g=; b=tUtKe4GvhqRUKU mmC4tI8zW63hl8K+aySp7KHtSvpHc4czyK5lZMMdIIoJHGZFoQzsIGHjlkBffHNWM68sw2D6ckOaE O4cfIoj0pSWBFqfdqDG/rZFOEEiTDiBZOKbH9eAiKYPzQ8ImgdF/8QoxjZIM7dz9lw6sAtlnfng2j 3VaTINu5PpMsjrbl0dBQSYMkXhoty4MVBrDI/DdQhFw8kfyl4CCz39Wu5zvbUQAf3jHYJfrxx3qFn R/YOG2JaP20lM0kB2A8sB5tzqVIb70PmuNR4b/72SZj14JzPKScX1rYMqCMkIHu22E4RyyOHrrUgb urQ6H4/3MXsZ6JirACIQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hMXZl-00059w-4g; Fri, 03 May 2019 12:46:05 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hMXYt-0003V9-6Z for linux-arm-kernel@lists.infradead.org; Fri, 03 May 2019 12:45:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DD82D1682; Fri, 3 May 2019 05:45:10 -0700 (PDT) Received: from filthy-habits.cambridge.arm.com (filthy-habits.cambridge.arm.com [10.1.197.61]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A3EEF3F220; Fri, 3 May 2019 05:45:07 -0700 (PDT) From: Marc Zyngier To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Subject: [PATCH 08/56] arm64/sve: Enable SVE state tracking for non-task contexts Date: Fri, 3 May 2019 13:43:39 +0100 Message-Id: <20190503124427.190206-9-marc.zyngier@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190503124427.190206-1-marc.zyngier@arm.com> References: <20190503124427.190206-1-marc.zyngier@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190503_054512_049954_5AB8A6A0 X-CRM114-Status: GOOD ( 18.63 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Maydell , Andrew Jones , kvm@vger.kernel.org, Julien Thierry , Suzuki K Poulose , Will Deacon , Christoffer Dall , Kristina Martsenko , "zhang . lei" , Julien Grall , kvmarm@lists.cs.columbia.edu, Amit Daniel Kachhap , Andrew Murray , =?utf-8?q?Alex_Benn=C3=A9e?= , Dave Martin , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Dave Martin The current FPSIMD/SVE context handling support for non-task (i.e., KVM vcpu) contexts does not take SVE into account. This means that only task contexts can safely use SVE at present. In preparation for enabling KVM guests to use SVE, it is necessary to keep track of SVE state for non-task contexts too. This patch adds the necessary support, removing assumptions from the context switch code about the location of the SVE context storage. When binding a vcpu context, its vector length is arbitrarily specified as SVE_VL_MIN for now. In any case, because TIF_SVE is presently cleared at vcpu context bind time, the specified vector length will not be used for anything yet. In later patches TIF_SVE will be set here as appropriate, and the appropriate maximum vector length for the vcpu will be passed when binding. Signed-off-by: Dave Martin Reviewed-by: Alex BennĂ©e Reviewed-by: Julien Grall Tested-by: zhang.lei Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/fpsimd.h | 3 ++- arch/arm64/kernel/fpsimd.c | 20 +++++++++++++++----- arch/arm64/kvm/fpsimd.c | 5 ++++- 3 files changed, 21 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 964adc9f312d..df7a14305222 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -56,7 +56,8 @@ extern void fpsimd_restore_current_state(void); extern void fpsimd_update_current_state(struct user_fpsimd_state const *state); extern void fpsimd_bind_task_to_cpu(void); -extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state); +extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state, + void *sve_state, unsigned int sve_vl); extern void fpsimd_flush_task_state(struct task_struct *target); extern void fpsimd_flush_cpu_state(void); diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index b219796a4081..8a93afa78600 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -121,6 +121,8 @@ */ struct fpsimd_last_state_struct { struct user_fpsimd_state *st; + void *sve_state; + unsigned int sve_vl; }; static DEFINE_PER_CPU(struct fpsimd_last_state_struct, fpsimd_last_state); @@ -241,14 +243,15 @@ static void task_fpsimd_load(void) */ void fpsimd_save(void) { - struct user_fpsimd_state *st = __this_cpu_read(fpsimd_last_state.st); + struct fpsimd_last_state_struct const *last = + this_cpu_ptr(&fpsimd_last_state); /* set by fpsimd_bind_task_to_cpu() or fpsimd_bind_state_to_cpu() */ WARN_ON(!in_softirq() && !irqs_disabled()); if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) { if (system_supports_sve() && test_thread_flag(TIF_SVE)) { - if (WARN_ON(sve_get_vl() != current->thread.sve_vl)) { + if (WARN_ON(sve_get_vl() != last->sve_vl)) { /* * Can't save the user regs, so current would * re-enter user with corrupt state. @@ -258,9 +261,11 @@ void fpsimd_save(void) return; } - sve_save_state(sve_pffr(¤t->thread), &st->fpsr); + sve_save_state((char *)last->sve_state + + sve_ffr_offset(last->sve_vl), + &last->st->fpsr); } else - fpsimd_save_state(st); + fpsimd_save_state(last->st); } } @@ -1034,6 +1039,8 @@ void fpsimd_bind_task_to_cpu(void) this_cpu_ptr(&fpsimd_last_state); last->st = ¤t->thread.uw.fpsimd_state; + last->sve_state = current->thread.sve_state; + last->sve_vl = current->thread.sve_vl; current->thread.fpsimd_cpu = smp_processor_id(); if (system_supports_sve()) { @@ -1047,7 +1054,8 @@ void fpsimd_bind_task_to_cpu(void) } } -void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st) +void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state, + unsigned int sve_vl) { struct fpsimd_last_state_struct *last = this_cpu_ptr(&fpsimd_last_state); @@ -1055,6 +1063,8 @@ void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st) WARN_ON(!in_softirq() && !irqs_disabled()); last->st = st; + last->sve_state = sve_state; + last->sve_vl = sve_vl; } /* diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index aac7808ce216..1cf4f0269471 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -85,7 +86,9 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) WARN_ON_ONCE(!irqs_disabled()); if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { - fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.gp_regs.fp_regs); + fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.gp_regs.fp_regs, + NULL, SVE_VL_MIN); + clear_thread_flag(TIF_FOREIGN_FPSTATE); clear_thread_flag(TIF_SVE); }