From patchwork Tue Mar 18 17:01:43 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 875533 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1494120FA85; Tue, 18 Mar 2025 17:02:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742317359; cv=none; b=Mq9v7PYxiGNId447+e8IYwEUharR2kivyBIocZUDix+29wWdS8GzPC/UMtoUJCzcMcQgJau+ml1HdEM8nn10VGAEuEm6rwEf2SHjcMBgsVH1guhi9QyLy2dgAlZwR2IWd5Br1X4DYD/Nzt4J4Tan+sMEhhuTGbOHbzLA/R7accE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742317359; c=relaxed/simple; bh=k6j3DBsimegxPoU9UiZ9TSkg2hg0aryPCM5hJl5zw4g=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qm5mbT+mb2dAzUqdTXTNJjIpFVjAaQez5AWQ2CSlOWcFLdWXiBXRmzrrl6ewnav1A5zcJhkAFL1NRrcDLOUcOLqGTxtULGsJv7dYPq+wmWmEM+4Xur1/oladNseZK08VKnh/T2n28dMD0DtiSp3SKYxiHNkUEBpKjUCMFFqPak8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5A8001BF7; Tue, 18 Mar 2025 10:02:45 -0700 (PDT) Received: from e133711.arm.com (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0A2A53F673; Tue, 18 Mar 2025 10:02:35 -0700 (PDT) From: Sudeep Holla Date: Tue, 18 Mar 2025 17:01:43 +0000 Subject: [PATCH v2 5/8] virt: efi_secret: Transition to the faux device interface Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250318-plat2faux_dev-v2-5-e6cc73f78478@arm.com> References: <20250318-plat2faux_dev-v2-0-e6cc73f78478@arm.com> In-Reply-To: <20250318-plat2faux_dev-v2-0-e6cc73f78478@arm.com> To: linux-kernel@vger.kernel.org Cc: Sudeep Holla , Greg Kroah-Hartman , Ard Biesheuvel , linux-efi@vger.kernel.org X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=4350; i=sudeep.holla@arm.com; h=from:subject:message-id; bh=k6j3DBsimegxPoU9UiZ9TSkg2hg0aryPCM5hJl5zw4g=; b=owEBbQKS/ZANAwAIAQBBurwxfuKYAcsmYgBn2aciefH/zbE9cqyOtTLIfCPlafuR7jl/RVr/f rkxbVS6LgOJAjMEAAEIAB0WIQS6ceUSBvMeskPdk+EAQbq8MX7imAUCZ9mnIgAKCRAAQbq8MX7i mJO4D/4wgOELwUSW3aUd98WcEmrln+VhUVv4IND46FmOMaLpLzOPpA4zIA0yrVUMS+iJO8HVy92 nh4r27qvdgXBNORd3jej4FswWHuPHBV07OZrwVCEGDUQVPevirLb1FeT23ZSkCxchWsuWMgKtt9 +GXgXqzI1RhXTyTmw3DRmzbWeSzjnrANxekYJOx1u8Qitn6DMSoYDktuaGiVH50kp4trjhQZo9k TQrAZQsEh30lk+18+uzjivnlpBeJgUN8CG/9m3f0OR9BHSoZbY9EWp0YhkfGmnVxFX10UvQacMq r0oDVhQIZ1xtKZja3tY2jO6omSIH3CxridohV7EMgjDJ3/pFjCN9KYdqeQrI7/+GJnk6eAEygUM wpunQDRO2iyjGmFUGuBj4JV5DN4+IVY5bXdAXQhdpFpxV8RG6N/OA4TxnmoMOABOCcd707gbtUi lm7Mw4e8CH1OZtdn/5Pb4rXUjykcNNtdirM/KKREGJmuT0j69LDcc8x2npo2TSh6HtQkm+W3LPQ 2Z8zQo8BQN6DnFqJcu/7BDLeflK9Rg1yX2kqFRdKhgFZ5uEn7jICyTP5616vTZaORzucJsEtkQN zirUeRcMCC/B6+sJTmbhkq5l5AvQGOPB96Ldy93CcYriykU2xId03YvkziUD0BE+h67Z0B5p/2U 1efnVjM+GiVDahg== X-Developer-Key: i=sudeep.holla@arm.com; a=openpgp; fpr=7360A21742ADF5A11767C1C139CFD4755FE2D5B4 The EFI secret area driver does not require the creation of a platform device. Originally, this approach was chosen for simplicity when the driver was first implemented. With the introduction of the lightweight faux device interface, we now have a more appropriate alternative. Migrate the driver to utilize the faux bus, given that the platform device it previously created was not a real one anyway. This will simplify the code, reducing its footprint while maintaining functionality. Cc: Ard Biesheuvel Cc: linux-efi@vger.kernel.org Signed-off-by: Sudeep Holla --- drivers/firmware/efi/efi.c | 5 ----- drivers/virt/coco/efi_secret/efi_secret.c | 29 ++++++++--------------------- 2 files changed, 8 insertions(+), 26 deletions(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 8aebc747c65bc1b63d514a50fe6f35a9e3c1af0a..862b7744c28ecc9e5a64bbb3533c34119f50267f 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -465,11 +465,6 @@ static int __init efisubsys_init(void) if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS)) efi_debugfs_init(); -#ifdef CONFIG_EFI_COCO_SECRET - if (efi.coco_secret != EFI_INVALID_TABLE_ADDR) - platform_device_register_simple("efi_secret", 0, NULL, 0); -#endif - return 0; err_remove_group: diff --git a/drivers/virt/coco/efi_secret/efi_secret.c b/drivers/virt/coco/efi_secret/efi_secret.c index 1864f9f80617e082feb574a15327949972c8cc1e..a60976750bef787c78401bf4569ee5d0c7d2b5f4 100644 --- a/drivers/virt/coco/efi_secret/efi_secret.c +++ b/drivers/virt/coco/efi_secret/efi_secret.c @@ -16,7 +16,7 @@ * is the GUID of the secret entry, and its content is the secret data. */ -#include +#include #include #include #include @@ -152,17 +152,12 @@ static const struct inode_operations efi_secret_dir_inode_operations = { .unlink = efi_secret_unlink, }; -static int efi_secret_map_area(struct platform_device *dev) +static int efi_secret_map_area(struct faux_device *dev) { int ret; struct efi_secret *s = efi_secret_get(); struct linux_efi_coco_secret_area *secret_area; - if (efi.coco_secret == EFI_INVALID_TABLE_ADDR) { - dev_err(&dev->dev, "Secret area address is not available\n"); - return -EINVAL; - } - secret_area = memremap(efi.coco_secret, sizeof(*secret_area), MEMREMAP_WB); if (secret_area == NULL) { dev_err(&dev->dev, "Could not map secret area EFI config entry\n"); @@ -191,7 +186,7 @@ static int efi_secret_map_area(struct platform_device *dev) return ret; } -static void efi_secret_securityfs_teardown(struct platform_device *dev) +static void efi_secret_securityfs_teardown(struct faux_device *dev) { struct efi_secret *s = efi_secret_get(); int i; @@ -210,7 +205,7 @@ static void efi_secret_securityfs_teardown(struct platform_device *dev) dev_dbg(&dev->dev, "Removed securityfs entries\n"); } -static int efi_secret_securityfs_setup(struct platform_device *dev) +static int efi_secret_securityfs_setup(struct faux_device *dev) { struct efi_secret *s = efi_secret_get(); int ret = 0, i = 0, bytes_left; @@ -307,7 +302,7 @@ static void efi_secret_unmap_area(void) } } -static int efi_secret_probe(struct platform_device *dev) +static int efi_secret_probe(struct faux_device *dev) { int ret; @@ -326,23 +321,15 @@ static int efi_secret_probe(struct platform_device *dev) return ret; } -static void efi_secret_remove(struct platform_device *dev) +static void efi_secret_remove(struct faux_device *dev) { efi_secret_securityfs_teardown(dev); efi_secret_unmap_area(); } -static struct platform_driver efi_secret_driver = { - .probe = efi_secret_probe, - .remove = efi_secret_remove, - .driver = { - .name = "efi_secret", - }, -}; - -module_platform_driver(efi_secret_driver); +module_faux_driver(efi_secret, efi_secret_probe, efi_secret_remove, + efi.coco_secret != EFI_INVALID_TABLE_ADDR); MODULE_DESCRIPTION("Confidential computing EFI secret area access"); MODULE_AUTHOR("IBM"); MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:efi_secret");