linux-coco.lists.linux.dev archive mirror
 help / color / mirror / Atom feed
From: Dov Murik <dovmurik@linux.ibm.com>
To: linux-efi@vger.kernel.org
Cc: Dov Murik <dovmurik@linux.ibm.com>,
	Laszlo Ersek <lersek@redhat.com>,
	Ashish Kalra <ashish.kalra@amd.com>,
	Brijesh Singh <brijesh.singh@amd.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Ard Biesheuvel <ardb@kernel.org>,
	James Morris <jmorris@namei.org>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	Andi Kleen <ak@linux.intel.com>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	James Bottomley <jejb@linux.ibm.com>,
	Tobin Feldman-Fitzthum <tobin@linux.ibm.com>,
	Jim Cadden <jcadden@ibm.com>,
	linux-coco@lists.linux.dev,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [RFC PATCH v2 2/3] efi: Reserve confidential computing secret area
Date: Mon, 28 Jun 2021 18:34:30 +0000	[thread overview]
Message-ID: <20210628183431.953934-3-dovmurik@linux.ibm.com> (raw)
In-Reply-To: <20210628183431.953934-1-dovmurik@linux.ibm.com>

When efi-stub copies an EFI-provided confidential computing secret area,
reserve that memory block for future use within the kernel.

Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
---
 drivers/firmware/efi/Makefile                 |  2 +-
 drivers/firmware/efi/confidential-computing.c | 41 +++++++++++++++++++
 drivers/firmware/efi/efi.c                    |  5 +++
 include/linux/efi.h                           |  4 ++
 4 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 drivers/firmware/efi/confidential-computing.c

diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 467e94259679..63f21f7351da 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -12,7 +12,7 @@ KASAN_SANITIZE_runtime-wrappers.o	:= n
 
 obj-$(CONFIG_ACPI_BGRT) 		+= efi-bgrt.o
 obj-$(CONFIG_EFI)			+= efi.o vars.o reboot.o memattr.o tpm.o
-obj-$(CONFIG_EFI)			+= memmap.o
+obj-$(CONFIG_EFI)			+= memmap.o confidential-computing.o
 ifneq ($(CONFIG_EFI_CAPSULE_LOADER),)
 obj-$(CONFIG_EFI)			+= capsule.o
 endif
diff --git a/drivers/firmware/efi/confidential-computing.c b/drivers/firmware/efi/confidential-computing.c
new file mode 100644
index 000000000000..e6bb4d1e8f17
--- /dev/null
+++ b/drivers/firmware/efi/confidential-computing.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Confidential computing secret area handling
+ *
+ * Copyright (C) 2021 IBM Corporation
+ * Author: Dov Murik <dovmurik@linux.ibm.com>
+ */
+
+#define pr_fmt(fmt) "efi: " fmt
+
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <asm/early_ioremap.h>
+
+/*
+ * Reserve the confidential computing secret area memory
+ */
+int __init efi_confidential_computing_secret_area_reserve(void)
+{
+	struct linux_efi_confidential_computing_secret_area *secret_area;
+	unsigned long secret_area_size;
+
+	if (efi.confidential_computing_secret == EFI_INVALID_TABLE_ADDR)
+		return 0;
+
+	secret_area = early_memremap(efi.confidential_computing_secret, sizeof(*secret_area));
+	if (!secret_area) {
+		pr_err("Failed to map confidential computing secret area\n");
+		efi.confidential_computing_secret = EFI_INVALID_TABLE_ADDR;
+		return -ENOMEM;
+	}
+
+	secret_area_size = sizeof(*secret_area) + secret_area->size;
+	memblock_reserve(efi.confidential_computing_secret, secret_area_size);
+
+	pr_info("Reserved memory of EFI-provided confidential computing secret area");
+
+	early_memunmap(secret_area, sizeof(*secret_area));
+	return 0;
+}
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 4b7ee3fa9224..da36333e5c9f 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -526,6 +526,9 @@ static const efi_config_table_type_t common_tables[] __initconst = {
 #ifdef CONFIG_LOAD_UEFI_KEYS
 	{LINUX_EFI_MOK_VARIABLE_TABLE_GUID,	&efi.mokvar_table,	"MOKvar"	},
 #endif
+	{LINUX_EFI_CONFIDENTIAL_COMPUTING_SECRET_AREA_GUID,
+						&efi.confidential_computing_secret,
+									"ConfCompSecret"},
 	{},
 };
 
@@ -613,6 +616,8 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
 
 	efi_tpm_eventlog_init();
 
+	efi_confidential_computing_secret_area_reserve();
+
 	if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
 		unsigned long prsv = mem_reserve;
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 4f647f1ee298..e9740bd16db0 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -551,6 +551,8 @@ extern struct efi {
 	unsigned long			tpm_log;		/* TPM2 Event Log table */
 	unsigned long			tpm_final_log;		/* TPM2 Final Events Log table */
 	unsigned long			mokvar_table;		/* MOK variable config table */
+	unsigned long			confidential_computing_secret;	/* Confidential computing */
+									/* secret table           */
 
 	efi_get_time_t			*get_time;
 	efi_set_time_t			*set_time;
@@ -1190,6 +1192,8 @@ extern int efi_tpm_final_log_size;
 
 extern unsigned long rci2_table_phys;
 
+extern int efi_confidential_computing_secret_area_reserve(void);
+
 /*
  * efi_runtime_service() function identifiers.
  * "NONE" is used by efi_recover_from_page_fault() to check if the page
-- 
2.25.1


  parent reply	other threads:[~2021-06-28 18:34 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-28 18:34 [RFC PATCH v2 0/3] Allow access to " Dov Murik
2021-06-28 18:34 ` [RFC PATCH v2 1/3] efi/libstub: Copy " Dov Murik
2021-06-28 18:34 ` Dov Murik [this message]
2021-06-28 20:40   ` [RFC PATCH v2 2/3] efi: Reserve " Tom Lendacky
2021-06-29  6:04     ` Dov Murik
2021-06-28 18:34 ` [RFC PATCH v2 3/3] virt: Add sev_secret module to expose confidential computing secrets Dov Murik
2021-06-28 19:30   ` Borislav Petkov
2021-06-29  7:23     ` Dov Murik
2021-06-29 22:48       ` Borislav Petkov
2021-06-28 19:28 ` [RFC PATCH v2 0/3] Allow access to confidential computing secret area Borislav Petkov
2021-06-29  7:16   ` Dov Murik
2021-06-29 17:33     ` Borislav Petkov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210628183431.953934-3-dovmurik@linux.ibm.com \
    --to=dovmurik@linux.ibm.com \
    --cc=ak@linux.intel.com \
    --cc=ardb@kernel.org \
    --cc=ashish.kalra@amd.com \
    --cc=brijesh.singh@amd.com \
    --cc=dgilbert@redhat.com \
    --cc=jcadden@ibm.com \
    --cc=jejb@linux.ibm.com \
    --cc=jmorris@namei.org \
    --cc=lersek@redhat.com \
    --cc=linux-coco@lists.linux.dev \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=serge@hallyn.com \
    --cc=thomas.lendacky@amd.com \
    --cc=tobin@linux.ibm.com \
    --subject='Re: [RFC PATCH v2 2/3] efi: Reserve confidential computing secret area' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).