From a59b50e995465911ba580df0bd10cf64aa81fc43 Mon Sep 17 00:00:00 2001 From: Joseph Cihula Date: Tue, 30 Jun 2009 19:31:10 -0700 Subject: [PATCH] intel_txt: Force IOMMU on for Intel TXT launch The tboot module will DMA protect all of memory in order to ensure the that kernel will be able to initialize without compromise (from DMA). Consequently, the kernel must enable Intel Virtualization Technology for Directed I/O (VT-d or Intel IOMMU) in order to replace this broad protection with the appropriate page-granular protection. Otherwise DMA devices will be unable to read or write from memory and the kernel will eventually panic. Because runtime IOMMU support is configurable by command line options, this patch will force it to be enabled regardless of the options specified, and will log a message if it was required to force it on. dmar.c | 7 +++++++ intel-iommu.c | 17 +++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-) Signed-off-by: Joseph Cihula Signed-off-by: Shane Wang Cc: David Woodhouse Signed-off-by: H. Peter Anvin --- drivers/pci/dmar.c | 7 +++++++ drivers/pci/intel-iommu.c | 17 +++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 7b287cb38b7a..0cbc5fd26c3c 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -33,6 +33,7 @@ #include #include #include +#include #undef PREFIX #define PREFIX "DMAR:" @@ -413,6 +414,12 @@ parse_dmar_table(void) */ dmar_table_detect(); + /* + * ACPI tables may not be DMA protected by tboot, so use DMAR copy + * SINIT saved in SinitMleData in TXT heap (which is DMA protected) + */ + dmar_tbl = tboot_get_dmar_table(dmar_tbl); + dmar = (struct acpi_table_dmar *)dmar_tbl; if (!dmar) return -ENODEV; diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index ebc9b8dca881..2dc72a6d7412 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include "pci.h" @@ -3183,12 +3184,22 @@ static int __init init_iommu_sysfs(void) int __init intel_iommu_init(void) { int ret = 0; + int force_on = 0; - if (dmar_table_init()) + /* VT-d is required for a TXT/tboot launch, so enforce that */ + force_on = tboot_force_iommu(); + + if (dmar_table_init()) { + if (force_on) + panic("tboot: Failed to initialize DMAR table\n"); return -ENODEV; + } - if (dmar_dev_scope_init()) + if (dmar_dev_scope_init()) { + if (force_on) + panic("tboot: Failed to initialize DMAR device scope\n"); return -ENODEV; + } /* * Check the need for DMA-remapping initialization now. @@ -3204,6 +3215,8 @@ int __init intel_iommu_init(void) ret = init_dmars(); if (ret) { + if (force_on) + panic("tboot: Failed to initialize DMARs\n"); printk(KERN_ERR "IOMMU: dmar init failed\n"); put_iova_domain(&reserved_iova_list); iommu_exit_mempool(); -- 2.39.5