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From:   Ross Philipson <ross.philipson@oracle.com>
To:     linux-kernel@vger.kernel.org, x86@kernel.org,
        iommu@lists.linux-foundation.org, linux-integrity@vger.kernel.org,
        linux-doc@vger.kernel.org
Cc:     ross.philipson@oracle.com, dpsmith@apertussolutions.com,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
        luto@amacapital.net, trenchboot-devel@googlegroups.com
Subject: [PATCH v2 12/12] iommu: Do not allow IOMMU passthrough with Secure Launch
Date:   Fri, 18 Jun 2021 12:12:57 -0400
Message-Id: <1624032777-7013-13-git-send-email-ross.philipson@oracle.com>
In-Reply-To: <1624032777-7013-1-git-send-email-ross.philipson@oracle.com>
References: <1624032777-7013-1-git-send-email-ross.philipson@oracle.com>
Precedence: bulk

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