From patchwork Mon Feb 18 19:52:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dave Martin X-Patchwork-Id: 10818781 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 CCBBC1390 for ; Mon, 18 Feb 2019 19:58:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B81292B7B2 for ; Mon, 18 Feb 2019 19:58:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AC33C2BAD8; Mon, 18 Feb 2019 19:58:17 +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 0BC092B7B2 for ; Mon, 18 Feb 2019 19:58:17 +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=7WHROeHHFjdNL7h8AmvcJ72IEmXOu9pyQpb7E5ax2dM=; b=DGpdZztTDBklpU xFQa69KjARbzujaAtgeCEsw28TWNk0OM8L+r5BmGwTmesoxba5Yxsr0abrPyyrTiglVIwMcwtvj0c VWBj5CQJu5IDJIzrGyu4LbQGVP9vTKCkbEM7El0tf572v79GFeAYBROJPpWXZ/ngHjtyBbg+7Il1m BFXRndg0ecvnmpHRGlYo0tNe1EkW3Oc8ulTvXNQvQzBK9nQ0IQnF0VV7O3vkoanvvzmp7eBJo+Kci eYjXThHLqUbZ6G8E5nI+qvYKVfOzw0RiFmMLvVTDb7i+RtDKneLhm4ggLFSwzdoEs0fopA2mY77mI EwasERppv+GCZ9pVTROA==; 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 1gvp3P-0001qx-Ok; Mon, 18 Feb 2019 19:58:15 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvozh-0004bM-MP for linux-arm-kernel@lists.infradead.org; Mon, 18 Feb 2019 19:54:38 +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 0A6991BB0; Mon, 18 Feb 2019 11:54:07 -0800 (PST) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A4D063FBF8; Mon, 18 Feb 2019 11:53:43 -0800 (PST) From: Dave Martin To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v5 08/26] arm64/sve: Enable SVE state tracking for non-task contexts Date: Mon, 18 Feb 2019 19:52:21 +0000 Message-Id: <1550519559-15915-9-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1550519559-15915-1-git-send-email-Dave.Martin@arm.com> References: <1550519559-15915-1-git-send-email-Dave.Martin@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190218_115426_297840_DD3F3F26 X-CRM114-Status: GOOD ( 17.00 ) 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: Peter Maydell , Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , Zhang Lei , Julien Grall , =?utf-8?q?Alex_Benn=C3=A9e?= , 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 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 --- 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 964adc9..df7a143 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 92c2331..09ee264 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 aac7808..1cf4f02 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); }