[coreboot-gerrit] Change in coreboot[master]: sec/intel/txt: Account for SINIT ACM's of different sizes

[Arthur Heymans (Code Review)]

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/46556 )

Change subject: sec/intel/txt: Account for SINIT ACM's of different sizes
......................................................................

sec/intel/txt: Account for SINIT ACM's of different sizes

This checks the size of the ACM at runtime before programming the TXT
SINIT BASE/SIZE and HEAP BASE/SIZE.

Change-Id: Ia3e81d051a03b54233eef6ccdc4740c1a709be40
Signed-off-by: Arthur Heymans 
---
M src/security/intel/txt/ramstage.c
1 file changed, 65 insertions(+), 17 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/56/46556/1

diff --git a/src/security/intel/txt/ramstage.c b/src/security/intel/txt/ramstage.c
index f532a2f..3105d30 100644
--- a/src/security/intel/txt/ramstage.c
+++ b/src/security/intel/txt/ramstage.c
@@ -194,6 +194,18 @@
    }
 }

+/* fms: find most significant bit set, stolen from Linux Kernel Source. */
+static inline unsigned int fms(unsigned int x)
+{
+	unsigned int r;
+
+	__asm__("bsrl %1,%0\n\t"
+		"jnz 1f\n\t"
+		"movl $0,%0\n"
+		"1:" : "=r" (r) : "mr" (x));
+	return r;
+}
+
 /**
  * Finalize the TXT device.
  *
@@ -274,22 +286,58 @@
    	       read32((void *)TXT_DPR));
    }

-	/*
-	 * Document Number: 558294
-	 * Chapter 5.5.6.3 Intel TXT Heap Memory Region
+	/* Document Number: 558294
+	 * Chapter 5.5.5.6 Intel TXT Device Memory
+	 *
+	 *  +------------+ TSEG_BASE / DPR.TOP
+	 *  | TXT HEAP   |
+	 *  +------------+ TSEG_BASE - 1 MiB + SINIT ACM SIZE
+	 *  | TXT SINIT  |
+	 *  +------------+ TSEG_BASE - 1 MiB
+	 *  | MLE code   |
+	 *  | Page Table |
+	 *  +------------+ TSEG_BASE - at least 3 MiB
     */
-	write64((void *)TXT_HEAP_SIZE, 0xE0000);
-	write64((void *)TXT_HEAP_BASE,
-		ALIGN_DOWN(tseg_base - read64((void *)TXT_HEAP_SIZE), 4096));
+
+	struct cbfsf fh;
+	uint32_t compression_algo;
+	size_t decompressed_size;
+
+	void *sinit_base = (void *)(tseg_base - 1 * MiB);
+
+	if (cbfs_boot_locate(&fh, CONFIG_INTEL_TXT_CBFS_SINIT_ACM, NULL)) {
+		printk(BIOS_ERR, "TEE-TXT: Couldn't locate SINIT ACM in CBFS.\n");
+		/* Clear where SINIT and Heap would have been. */
+		memset(sinit_base, 0, 1 * MiB);
+		return;
+	}
+
+	cbfsf_decompression_info(&fh, &compression_algo, &decompressed_size);
+
+	/* Align the SINIT size to a power of 2 */
+	const size_t sinit_size = IS_POWER_OF_2(decompressed_size) ?
+		decompressed_size : 1 << (fms(decompressed_size) + 1);
+
+	if (sinit_size >= 1 * MiB) {
+		printk(BIOS_ERR, "TEE-TXT: Invalid SINIT ACM size");
+		/* Clear where SINIT and Heap would have been. */
+		memset(sinit_base, 0, 1 * MiB);
+		return;
+	}

/*
     * Document Number: 558294
     * Chapter 5.5.6.2 SINIT Memory Region
     */
-	write64((void *)TXT_SINIT_SIZE, 0x20000);
-	write64((void *)TXT_SINIT_BASE,
-		ALIGN_DOWN(read64((void *)TXT_HEAP_BASE) -
-			   read64((void *)TXT_SINIT_SIZE), 4096));
+	write64((void *)TXT_SINIT_SIZE, sinit_size);
+	write64((void *)TXT_SINIT_BASE, (uint64_t)(uintptr_t)sinit_base);
+
+	/*
+	 * Document Number: 558294
+	 * Chapter 5.5.6.3 Intel TXT Heap Memory Region
+	 */
+	write64((void *)TXT_HEAP_SIZE, 1 * MiB - sinit_size);
+	write64((void *)TXT_HEAP_BASE, tseg_base - 1 * MiB + sinit_size);

/*
     * BIOS Data Format
@@ -309,12 +357,12 @@
    	data.bdr.version = 5;

data.bdr.no_logical_procs = dev_count_cpu();
-
-	void *sinit_base = (void *)(uintptr_t)read64((void *)TXT_SINIT_BASE);
-	data.bdr.bios_sinit_size = cbfs_boot_load_file(CONFIG_INTEL_TXT_CBFS_SINIT_ACM,
-						       sinit_base,
-						       read64((void *)TXT_SINIT_SIZE),
-						       CBFS_TYPE_RAW);
+	data.bdr.bios_sinit_size = cbfs_load_and_decompress(&fh.data,
+							    0,
+							    region_device_sz(&fh.data),
+							    sinit_base,
+							    sinit_size,
+							    compression_algo);

if (data.bdr.bios_sinit_size) {
    	printk(BIOS_INFO, "TEE-TXT: Placing SINIT ACM in memory.\n");
@@ -323,7 +371,7 @@
    } else {
    	printk(BIOS_ERR, "TEE-TXT: Couldn't locate SINIT ACM in CBFS.\n");
    	/* Clear memory */
-		memset(sinit_base, 0, read64((void *)TXT_SINIT_SIZE));
+		memset(sinit_base, 0, sinit_size);
    }

struct cbfsf file;