From patchwork Wed Dec 8 00:03:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Zhong X-Patchwork-Id: 12662067 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9ABE9C433FE for ; Tue, 7 Dec 2021 15:09:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238535AbhLGPMp (ORCPT ); Tue, 7 Dec 2021 10:12:45 -0500 Received: from mga14.intel.com ([192.55.52.115]:5480 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238530AbhLGPMo (ORCPT ); Tue, 7 Dec 2021 10:12:44 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10190"; a="237820994" X-IronPort-AV: E=Sophos;i="5.87,293,1631602800"; d="scan'208";a="237820994" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2021 07:09:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,293,1631602800"; d="scan'208";a="461289759" Received: from icx.bj.intel.com ([10.240.192.117]) by orsmga003.jf.intel.com with ESMTP; 07 Dec 2021 07:09:10 -0800 From: Yang Zhong To: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, pbonzini@redhat.com Cc: seanjc@google.com, jun.nakajima@intel.com, kevin.tian@intel.com, jing2.liu@linux.intel.com, jing2.liu@intel.com, yang.zhong@intel.com Subject: [PATCH 02/19] x86/fpu: Prepare KVM for dynamically enabled states Date: Tue, 7 Dec 2021 19:03:42 -0500 Message-Id: <20211208000359.2853257-3-yang.zhong@intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211208000359.2853257-1-yang.zhong@intel.com> References: <20211208000359.2853257-1-yang.zhong@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Thomas Gleixner Add more fields for tracking per-vCPU permissions for dynamic XSTATE components: - user_xfeatures Track which features are currently enabled for the vCPU - user_perm Copied from guest_perm of the group leader thread. The first vCPU which does the copy locks the guest_perm - realloc_request KVM sets this field to request dynamically-enabled features which require reallocation of @fpstate Initialize those fields properly. Signed-off-by: Thomas Gleixner Signed-off-by: Jing Liu Signed-off-by: Yang Zhong --- arch/x86/include/asm/fpu/types.h | 23 +++++++++++++++++++++++ arch/x86/kernel/fpu/core.c | 26 +++++++++++++++++++++++++- 2 files changed, 48 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 6ddf80637697..861cffca3209 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -504,6 +504,29 @@ struct fpu { * Guest pseudo FPU container */ struct fpu_guest { + /* + * @user_xfeatures: xfeature bitmap of features which are + * currently enabled for the guest vCPU. + */ + u64 user_xfeatures; + + /* + * @user_perm: xfeature bitmap of features which are + * permitted to be enabled for the guest + * vCPU. + */ + u64 user_perm; + + /* + * @realloc_request: xfeature bitmap of features which are + * requested to be enabled dynamically + * which requires reallocation of @fpstate + * + * Set by an intercept handler and + * evaluated in fpu_swap_kvm_fpstate() + */ + u64 realloc_request; + /* * @fpstate: Pointer to the allocated guest fpstate */ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index ab19b3d8b2f7..fe592799508c 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -201,6 +201,26 @@ void fpu_reset_from_exception_fixup(void) #if IS_ENABLED(CONFIG_KVM) static void __fpstate_reset(struct fpstate *fpstate); +static void fpu_init_guest_permissions(struct fpu_guest *gfpu) +{ + struct fpu_state_perm *fpuperm; + u64 perm; + + if (!IS_ENABLED(CONFIG_X86_64)) + return; + + spin_lock_irq(¤t->sighand->siglock); + fpuperm = ¤t->group_leader->thread.fpu.guest_perm; + perm = fpuperm->__state_perm; + + /* First fpstate allocation locks down permissions. */ + WRITE_ONCE(fpuperm->__state_perm, perm | FPU_GUEST_PERM_LOCKED); + + spin_unlock_irq(¤t->sighand->siglock); + + gfpu->user_perm = perm & ~FPU_GUEST_PERM_LOCKED; +} + bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) { struct fpstate *fpstate; @@ -216,7 +236,11 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) fpstate->is_valloc = true; fpstate->is_guest = true; - gfpu->fpstate = fpstate; + gfpu->fpstate = fpstate; + gfpu->user_xfeatures = fpu_user_cfg.default_features; + gfpu->user_perm = fpu_user_cfg.default_features; + fpu_init_guest_permissions(gfpu); + return true; } EXPORT_SYMBOL_GPL(fpu_alloc_guest_fpstate);