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authorShane Wang <shane.wang@intel.com>2010-03-10 06:36:10 (GMT)
committerH. Peter Anvin <hpa@zytor.com>2010-03-19 20:39:58 (GMT)
commit4bd96a7a8185755b091233b16034c7436cbf57af (patch)
tree5a6d1a5014a39f0463c79abda29a482f4dd52dd1 /Documentation/intel_txt.txt
parenta3d3203e4bb40f253b1541e310dc0f9305be7c84 (diff)
x86, tboot: Add support for S3 memory integrity protection
This patch adds support for S3 memory integrity protection within an Intel(R) TXT launched kernel, for all kernel and userspace memory. All RAM used by the kernel and userspace, as indicated by memory ranges of type E820_RAM and E820_RESERVED_KERN in the e820 table, will be integrity protected. The MAINTAINERS file is also updated to reflect the maintainers of the TXT-related code. All MACing is done in tboot, based on a complexity analysis and tradeoff. v3: Compared with v2, this patch adds a check of array size in tboot.c, and a note to specify which c/s of tboot supports this kind of MACing in intel_txt.txt. Signed-off-by: Shane Wang <shane.wang@intel.com> LKML-Reference: <4B973DDA.6050902@intel.com> Signed-off-by: Joseph Cihula <joseph.cihula@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'Documentation/intel_txt.txt')
-rw-r--r--Documentation/intel_txt.txt16
1 files changed, 9 insertions, 7 deletions
diff --git a/Documentation/intel_txt.txt b/Documentation/intel_txt.txt
index f40a1f0..87c8990 100644
--- a/Documentation/intel_txt.txt
+++ b/Documentation/intel_txt.txt
@@ -161,13 +161,15 @@ o In order to put a system into any of the sleep states after a TXT
has been restored, it will restore the TPM PCRs and then
transfer control back to the kernel's S3 resume vector.
In order to preserve system integrity across S3, the kernel
- provides tboot with a set of memory ranges (kernel
- code/data/bss, S3 resume code, and AP trampoline) that tboot
- will calculate a MAC (message authentication code) over and then
- seal with the TPM. On resume and once the measured environment
- has been re-established, tboot will re-calculate the MAC and
- verify it against the sealed value. Tboot's policy determines
- what happens if the verification fails.
+ provides tboot with a set of memory ranges (RAM and RESERVED_KERN
+ in the e820 table, but not any memory that BIOS might alter over
+ the S3 transition) that tboot will calculate a MAC (message
+ authentication code) over and then seal with the TPM. On resume
+ and once the measured environment has been re-established, tboot
+ will re-calculate the MAC and verify it against the sealed value.
+ Tboot's policy determines what happens if the verification fails.
+ Note that the c/s 194 of tboot which has the new MAC code supports
+ this.
That's pretty much it for TXT support.

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