[PATCH v2 12/12] iommu: Do not allow IOMMU passthrough with Secure Launch

Ross Philipson
2021-06-18T16:07:24Z

The IOMMU should always be set to default translated type after
the PMRs are disabled to protect the MLE from DMA.

Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
---
drivers/iommu/intel/iommu.c | 5 +++++
drivers/iommu/iommu.c | 6 +++++-
2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index be35284..4f0256d 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -41,6 +41,7 @@
#include <linux/dma-direct.h>
#include <linux/crash_dump.h>
#include <linux/numa.h>
+#include <linux/slaunch.h>
#include <asm/irq_remapping.h>
#include <asm/cacheflush.h>
#include <asm/iommu.h>
@@ -2877,6 +2878,10 @@ static bool device_is_rmrr_locked(struct device *dev)
*/
static int device_def_domain_type(struct device *dev)
{
+ /* Do not allow identity domain when Secure Launch is configured */
+ if (slaunch_get_flags() & SL_FLAG_ACTIVE)
+ return IOMMU_DOMAIN_DMA;
+
if (dev_is_pci(dev)) {
struct pci_dev *pdev = to_pci_dev(dev);

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 808ab70d..d49b7dd 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -23,6 +23,7 @@
#include <linux/property.h>
#include <linux/fsl/mc.h>
#include <linux/module.h>
+#include <linux/slaunch.h>
#include <trace/events/iommu.h>

static struct kset *iommu_group_kset;
@@ -2761,7 +2762,10 @@ void iommu_set_default_passthrough(bool cmd_line)
{
if (cmd_line)
iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API;
- iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
+
+ /* Do not allow identity domain when Secure Launch is configured */
+ if (!(slaunch_get_flags() & SL_FLAG_ACTIVE))
+ iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
}

void iommu_set_default_translated(bool cmd_line)
--
1.8.3.1