From nobody Tue Oct 7 03:47:51 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (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 641972E1734; Tue, 15 Jul 2025 12:41:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752583293; cv=none; b=OF1Ra5dkG6azTYeqtwT3WHHFNC8ntycgkoIqKCZUXO6tAQcDyaY8tGJSiUzy9ac6byHbqUXo8qksGWMWJPKBz0jwflaMYFmaY7ThvxTxolgWJbITOJL6vVMviPThrd09cRRVNHyeltMMoTr766X2OmAhNGr+Y3oDV37qAE4TW2Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752583293; c=relaxed/simple; bh=nuaXZrkc4KSZxzqg0wh6FUNxF/aVlCe5hXHpamEieyk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i+h4q99PUVTNxk79ddqUptnHmmvSS4p+Q62SRh/HlGbTTI1eq7PfElDccASeXMTMdPYXoerrHVl1EfkRB781tGoZCQrRWTGKfnk8YR8XOKy6phnJ51/c5PL8Gu1+PswSNNx9jH3SLVbAQcOAyrmVRtk++fiXcbFnpWpLIadFtlQ= 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=P+5hjcCI; arc=none smtp.client-ip=192.198.163.9 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="P+5hjcCI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1752583291; x=1784119291; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=nuaXZrkc4KSZxzqg0wh6FUNxF/aVlCe5hXHpamEieyk=; b=P+5hjcCIQsK5QSYSOWRnnBfUg0HyCNIG3fxuOWRViiqyzVG8/Yj6tU4W u2hbiqc2HCJQCjiMWqkwFulVhE+9PYqk8f0Os4nNAnfAjExSNn2E7s9Yv VrsO6b432e+R1e+/T8fMTUob7YXMSJ2y/2d9PicVcFFHhbY4HSxS2AfWg Hyf4mndudG27DbIgG660f8HeJ6I4GbpzbeAK7WyjCWg/CLdMX1IUoARBi D4g3UFsi6PyAjeveio95huluamGloI7i3bU/W3H6F6NQWbfkJq9RD9HXH I/T0z9vDKvSObr83cy8Ti201d+FyiX/MapofkyNOlPvrg2W4RKU4JAGVS w==; X-CSE-ConnectionGUID: CfdrEnRpQYOIcRbV/WFSKA== X-CSE-MsgGUID: 1QpVVdnPTr+DV4LnwryoiA== X-IronPort-AV: E=McAfee;i="6800,10657,11493"; a="65498176" X-IronPort-AV: E=Sophos;i="6.16,313,1744095600"; d="scan'208";a="65498176" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jul 2025 05:41:31 -0700 X-CSE-ConnectionGUID: +ADNgoZYRwe6LmPzOXob5Q== X-CSE-MsgGUID: w8Bsf1HDTBCbyISJOSq2Qg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,313,1744095600"; d="scan'208";a="157018299" Received: from jkrzyszt-mobl2.ger.corp.intel.com (HELO eresheto-mobl3.ger.corp.intel.com) ([10.245.245.22]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jul 2025 05:41:26 -0700 From: Elena Reshetova To: dave.hansen@intel.com Cc: jarkko@kernel.org, seanjc@google.com, kai.huang@intel.com, mingo@kernel.org, linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, asit.k.mallick@intel.com, vincent.r.scarlata@intel.com, chongc@google.com, erdemaktas@google.com, vannapurve@google.com, bondarn@google.com, scott.raynor@intel.com, Elena Reshetova Subject: [PATCH v8 1/5] x86/sgx: Introduce a counter to count the sgx_(vepc_)open() Date: Tue, 15 Jul 2025 15:40:18 +0300 Message-ID: <20250715124109.1711717-2-elena.reshetova@intel.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250715124109.1711717-1-elena.reshetova@intel.com> References: <20250715124109.1711717-1-elena.reshetova@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Currently SGX does not have a global counter to count the active users from userspace or hypervisor. Implement such a counter, sgx_usage_count. It will be used by the driver when attempting to call EUPDATESVN SGX instruction. Note: the sgx_inc_usage_count prototype is defined to return int for the cleanliness of the follow-up patches. When the EUPDATESVN SGX instruction will be enabled in the follow-up patch, the sgx_inc_usage_count will start to return int. Suggested-by: Sean Christopherson Signed-off-by: Elena Reshetova --- arch/x86/kernel/cpu/sgx/driver.c | 22 ++++++++++++++++------ arch/x86/kernel/cpu/sgx/encl.c | 1 + arch/x86/kernel/cpu/sgx/main.c | 14 ++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 3 +++ arch/x86/kernel/cpu/sgx/virt.c | 16 ++++++++++++++-- 5 files changed, 48 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/dri= ver.c index 7f8d1e11dbee..a2994a74bdff 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -19,9 +19,15 @@ static int sgx_open(struct inode *inode, struct file *fi= le) struct sgx_encl *encl; int ret; =20 + ret =3D sgx_inc_usage_count(); + if (ret) + return ret; + encl =3D kzalloc(sizeof(*encl), GFP_KERNEL); - if (!encl) - return -ENOMEM; + if (!encl) { + ret =3D -ENOMEM; + goto err_usage_count; + } =20 kref_init(&encl->refcount); xa_init(&encl->page_array); @@ -31,14 +37,18 @@ static int sgx_open(struct inode *inode, struct file *f= ile) spin_lock_init(&encl->mm_lock); =20 ret =3D init_srcu_struct(&encl->srcu); - if (ret) { - kfree(encl); - return ret; - } + if (ret) + goto err_encl; =20 file->private_data =3D encl; =20 return 0; + +err_encl: + kfree(encl); +err_usage_count: + sgx_dec_usage_count(); + return ret; } =20 static int sgx_release(struct inode *inode, struct file *file) diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 279148e72459..3b54889ae4a4 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -765,6 +765,7 @@ void sgx_encl_release(struct kref *ref) WARN_ON_ONCE(encl->secs.epc_page); =20 kfree(encl); + sgx_dec_usage_count(); } =20 /* diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 2de01b379aa3..0e75090f93c9 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -917,6 +917,20 @@ int sgx_set_attribute(unsigned long *allowed_attribute= s, } EXPORT_SYMBOL_GPL(sgx_set_attribute); =20 +/* Counter to count the active SGX users */ +static int sgx_usage_count; + +int sgx_inc_usage_count(void) +{ + sgx_usage_count++; + return 0; +} + +void sgx_dec_usage_count(void) +{ + sgx_usage_count--; +} + static int __init sgx_init(void) { int ret; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index d2dad21259a8..f5940393d9bd 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -102,6 +102,9 @@ static inline int __init sgx_vepc_init(void) } #endif =20 +int sgx_inc_usage_count(void); +void sgx_dec_usage_count(void); + void sgx_update_lepubkeyhash(u64 *lepubkeyhash); =20 #endif /* _X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c index 7aaa3652e31d..6ce908ed51c9 100644 --- a/arch/x86/kernel/cpu/sgx/virt.c +++ b/arch/x86/kernel/cpu/sgx/virt.c @@ -255,22 +255,34 @@ static int sgx_vepc_release(struct inode *inode, stru= ct file *file) xa_destroy(&vepc->page_array); kfree(vepc); =20 + sgx_dec_usage_count(); return 0; } =20 static int sgx_vepc_open(struct inode *inode, struct file *file) { struct sgx_vepc *vepc; + int ret; + + ret =3D sgx_inc_usage_count(); + if (ret) + return ret; =20 vepc =3D kzalloc(sizeof(struct sgx_vepc), GFP_KERNEL); - if (!vepc) - return -ENOMEM; + if (!vepc) { + ret =3D -ENOMEM; + goto err_usage_count; + } mutex_init(&vepc->lock); xa_init(&vepc->page_array); =20 file->private_data =3D vepc; =20 return 0; + +err_usage_count: + sgx_dec_usage_count(); + return ret; } =20 static long sgx_vepc_ioctl(struct file *file, --=20 2.45.2