From nobody Sun Dec 14 19:32:30 2025 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (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 4741428313D; Thu, 22 May 2025 09:23:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747905784; cv=none; b=tyMVvGTNIsDQ6W2kAhC4xrGl8FAECSDQnrjyBml3lT5Pr3ca1KsB0MKn14xRWcwhaP1SLW5oskPHuz2TL6oIAbPlQhs7NHgzs4iOlcQtnOaPtvh3mdyd4j/aRtRwfwbp9YMujdH+aeIXRln+Kv9Ao09rgUdX8CudZ5v9IS3CHA4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747905784; c=relaxed/simple; bh=gXFPrPtwKLZsTD5Ey5rNSMwyikfjnKecvf8r8P40cfU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Vy9OOgKBKCXI5lY6+nGJ6p+vvbOjSVtV4ZjCYHdHfShaXninEo84iM2NRPdZJFPmdnqZx3mE5LmWfP+kQ+oAGSOK79za+Y6fL3rPhrny9IR/xNBVSQBZ59OMpF8yZyHsmiyAoVnYbm6kUQKz9U6rO3+22gOr2jz60MnwNTUlkpc= 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=W6zU02os; arc=none smtp.client-ip=198.175.65.9 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="W6zU02os" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1747905782; x=1779441782; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=gXFPrPtwKLZsTD5Ey5rNSMwyikfjnKecvf8r8P40cfU=; b=W6zU02oszcn9ExMtScXcsBsmAPZL6sp+VignjIFQQxyfpiNIr6nIqTzh bJggTaGTmguYVnIHGx7DgM1rqPNSp7MOgzpYjwu/Q13uDy8JOvWcbU9Cr Q6etnCa3M0+nUtOuAfSNfDefoA+AtTtfVIc4EnG2DlcPu135OVdbZnNKY AY0/aNq1bN7noQ7U77vQ9Vbh9fxrAYQwV6j9yyuuhdifO+xvkQT1aUhEh Vm8VJWEVxutsSrxWjHJqowvzbLXquF0EAJ7rfJfNv7Uc1u5T+CL1p3ySi WBVvVXG0Otam9mqS0ogvUr9b2yYFeRSVsrHfbKZW1Hm9qx5Xi3hDaZxpW g==; X-CSE-ConnectionGUID: j23rcIddTruO++yuN/kcbQ== X-CSE-MsgGUID: DrZ3cioqTWq3QGUX0KgNmw== X-IronPort-AV: E=McAfee;i="6700,10204,11440"; a="72445625" X-IronPort-AV: E=Sophos;i="6.15,305,1739865600"; d="scan'208";a="72445625" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 May 2025 02:23:02 -0700 X-CSE-ConnectionGUID: sxKsu8cIRWGZHiDA9wEkxg== X-CSE-MsgGUID: 2ViRFOWoRx61IS8j9fdeBw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,305,1739865600"; d="scan'208";a="145661947" Received: from oandoniu-mobl3.ger.corp.intel.com (HELO eresheto-mobl3.ger.corp.intel.com) ([10.245.245.170]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 May 2025 02:22:56 -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, dionnaglaze@google.com, bondarn@google.com, scott.raynor@intel.com, Elena Reshetova Subject: [PATCH v6 1/5] x86/sgx: Introduce a counter to count the sgx_(vepc_)open() Date: Thu, 22 May 2025 12:21:34 +0300 Message-ID: <20250522092237.7895-2-elena.reshetova@intel.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250522092237.7895-1-elena.reshetova@intel.com> References: <20250522092237.7895-1-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. 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..a018b01b8736 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 atomic64_t sgx_usage_count; + +int sgx_inc_usage_count(void) +{ + atomic64_inc(&sgx_usage_count); + return 0; +} + +void sgx_dec_usage_count(void) +{ + atomic64_dec(&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