From patchwork Fri Sep 28 13:39:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dave Martin X-Patchwork-Id: 10619969 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 8340D6CB for ; Fri, 28 Sep 2018 13:47:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7344B28938 for ; Fri, 28 Sep 2018 13:47:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 67BD828A5C; Fri, 28 Sep 2018 13:47:29 +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=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE 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 CA0C728938 for ; Fri, 28 Sep 2018 13:47:28 +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=9Z3X3hrytwbabt8OlkfUee0m2CWvc1S1J7Zq9PQmHWk=; b=hZWmBW+RyI6EVh 84n22KwwHtHg4Hr2gjk+CC+SIerDAovHzmLuW1Ikr0xMcqE9ul9ai3RPpmn5wnGEZ10h8+Xx7GWPu gKn7Ecmmd1uMLzi+yiNsnm7jvxWLo+U07qiCOcmWrESNpo7u8QfN+ADEOvHJELM0POOUZzzdunYpX C/R9lSxRg0/AEFJ/QhzaVb8xn88P06wmT2C5Ota7iW4fyGPbr3By1o865DLxPbI8PwG7zf2zxioQj AQA+TGEJfJgH9jWC/gzk3L4z90xp+eDgOPqk49mtdD3S2Kyfto1S0fdKMKhqUcjTjBk2/+2KLIGmr yiiNw5Qa3Uanf3o+au3g==; 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 1g5t72-0003NP-DV; Fri, 28 Sep 2018 13:47:20 +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 1g5t0f-0007oV-8m for linux-arm-kernel@lists.infradead.org; Fri, 28 Sep 2018 13:42:45 +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 BD4F316A3; Fri, 28 Sep 2018 06:40:28 -0700 (PDT) Received: from e103592.Emea.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 118D13F5B7; Fri, 28 Sep 2018 06:40:26 -0700 (PDT) From: Dave Martin To: kvmarm@lists.cs.columbia.edu Subject: [RFC PATCH v2 07/23] arm64/sve: Enable SVE state tracking for non-task contexts Date: Fri, 28 Sep 2018 14:39:11 +0100 Message-Id: <1538141967-15375-8-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1538141967-15375-1-git-send-email-Dave.Martin@arm.com> References: <1538141967-15375-1-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-20180928_064045_411972_8CC94B95 X-CRM114-Status: GOOD ( 17.16 ) 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 , =?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_max_vl 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 --- arch/arm64/include/asm/fpsimd.h | 3 ++- arch/arm64/kernel/fpsimd.c | 20 +++++++++++++++----- arch/arm64/kvm/fpsimd.c | 4 +++- 3 files changed, 20 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 d28042b..60c5e28 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); } } @@ -1035,6 +1040,8 @@ 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()) { @@ -1048,7 +1055,8 @@ 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); @@ -1056,6 +1064,8 @@ 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..55654cb 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -85,7 +85,9 @@ 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_max_vl); + clear_thread_flag(TIF_FOREIGN_FPSTATE); clear_thread_flag(TIF_SVE); }