From patchwork Tue Mar 18 15:31:52 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Gao X-Patchwork-Id: 14021163 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88FF020E6E4; Tue, 18 Mar 2025 15:30:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742311837; cv=none; b=UOdZkMvx6c6FkLUZhISYtBFi/Q4IkYDMLBUOv8I9d/8MQlZHfJdmEoSxpeQJJoo/He6Ltkz983i00tJLDh/KEl1QXFxyvPeUwbQQbcj+4Mdul+BBEVpF2xNgH6nnrO9JHmM+FQ6Z3wbBTxWKgO6ybNFdKboMD1j3h+VpVuciJC4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742311837; c=relaxed/simple; bh=9HeHdk992vPt0k3jgDoyiyk9O7G3efAu3/tJ/3loWmI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qvrqaci3ldrBhsf7Sd4VKVVpQ1dSL7BnXyQywbnJhnot5IUeKkkNSyp05x3vvg4Sbi3FZ70dEpfKrAYmrUN0EO24tUbjPWzfnTkn7fjDwo6xReJJNmoYixXBHDNU2EZ/jPOGjbHSvcN2luUfCPpDYqjPBbejYjo/oZCMPPdyqsU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=UDk/OqQG; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="UDk/OqQG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1742311835; x=1773847835; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9HeHdk992vPt0k3jgDoyiyk9O7G3efAu3/tJ/3loWmI=; b=UDk/OqQGbQylWbtS5XbooU+jsbeEA7j+/k067vDoGodGMysIkJDQ98EX MdDYiGRG1GG13O9bUM5F2zUcWGtPcJsIa4wColfRwnQGLgLeYJPcyXGCl ewTchLtSEcUA/Crv31G7bHUFZTVU79N2y7/Uael+OI4opn12p7Xvk8Vce K1l8TIPFKmX3bodLkrfma5XTQMXE2OB9v4nOcPS/316hycW298Wf2ekCq RQvdRJBjtAtS4Uvd/we10ySnpMHSWRv6TGqx8IP+E8l7Ck64NIUH1cXHc eQbY+ltOs+KSvLqP+RSw67ZBVZ7e5FzNBaJcBP+fnPXKkyQrJKKx+x4X0 w==; X-CSE-ConnectionGUID: ceq/4xl3RKeeQbhyOEWqlg== X-CSE-MsgGUID: gwCKpnMySZuuZSQ6+pPBcw== X-IronPort-AV: E=McAfee;i="6700,10204,11377"; a="46224150" X-IronPort-AV: E=Sophos;i="6.14,257,1736841600"; d="scan'208";a="46224150" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2025 08:30:35 -0700 X-CSE-ConnectionGUID: +5Kq97WORG2SE9ho5vANSQ== X-CSE-MsgGUID: DWmk5wYIRxOI/2Ctcjxgtg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,257,1736841600"; d="scan'208";a="122121838" Received: from spr.sh.intel.com ([10.239.53.19]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2025 08:30:29 -0700 From: Chao Gao To: x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, tglx@linutronix.de, dave.hansen@intel.com, seanjc@google.com, pbonzini@redhat.com Cc: peterz@infradead.org, rick.p.edgecombe@intel.com, weijiang.yang@intel.com, john.allen@amd.com, bp@alien8.de, chang.seok.bae@intel.com, xin3.li@intel.com, Chao Gao , Maxim Levitsky , Ingo Molnar , Dave Hansen , "H. Peter Anvin" , Samuel Holland , Mitchell Levy , Stanislav Spassov , Eric Biggers , Uros Bizjak Subject: [PATCH v4 2/8] x86/fpu: Drop @perm from guest pseudo FPU container Date: Tue, 18 Mar 2025 23:31:52 +0800 Message-ID: <20250318153316.1970147-3-chao.gao@intel.com> X-Mailer: git-send-email 2.46.1 In-Reply-To: <20250318153316.1970147-1-chao.gao@intel.com> References: <20250318153316.1970147-1-chao.gao@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Remove @perm from the guest pseudo FPU container. The field is initialized during allocation and never used later. Rename fpu_init_guest_permissions() to show that its sole purpose is to lock down guest permissions. Suggested-by: Maxim Levitsky Signed-off-by: Chao Gao --- arch/x86/include/asm/fpu/types.h | 7 ------- arch/x86/kernel/fpu/core.c | 7 ++----- 2 files changed, 2 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 46cc263f9f4f..9f9ed406b179 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -526,13 +526,6 @@ struct fpu_guest { */ u64 xfeatures; - /* - * @perm: xfeature bitmap of features which are - * permitted to be enabled for the guest - * vCPU. - */ - u64 perm; - /* * @xfd_err: Save the guest value. */ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 1b734a9ff088..0b695c23bbfb 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -202,7 +202,7 @@ void fpu_reset_from_exception_fixup(void) #if IS_ENABLED(CONFIG_KVM) static void __fpstate_reset(struct fpstate *fpstate, u64 xfd); -static void fpu_init_guest_permissions(struct fpu_guest *gfpu) +static void fpu_lock_guest_permissions(struct fpu_guest *gfpu) { struct fpu_state_perm *fpuperm; u64 perm; @@ -218,8 +218,6 @@ static void fpu_init_guest_permissions(struct fpu_guest *gfpu) WRITE_ONCE(fpuperm->__state_perm, perm | FPU_GUEST_PERM_LOCKED); spin_unlock_irq(¤t->sighand->siglock); - - gfpu->perm = perm & ~FPU_GUEST_PERM_LOCKED; } bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) @@ -240,7 +238,6 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) gfpu->fpstate = fpstate; gfpu->xfeatures = fpu_kernel_cfg.default_features; - gfpu->perm = fpu_kernel_cfg.default_features; /* * KVM sets the FP+SSE bits in the XSAVE header when copying FPU state @@ -255,7 +252,7 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) if (WARN_ON_ONCE(fpu_user_cfg.default_size > gfpu->uabi_size)) gfpu->uabi_size = fpu_user_cfg.default_size; - fpu_init_guest_permissions(gfpu); + fpu_lock_guest_permissions(gfpu); return true; }