Add a stub implementation of iommu domain preserve for intel iommu
driver. This is required so that the iommu_domain is marked as
preserved.

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
---
 drivers/iommu/intel/iommu.c      | 6 ++++++
 drivers/iommu/intel/iommu.h      | 4 ++++
 drivers/iommu/intel/liveupdate.c | 9 +++++++++
 3 files changed, 19 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index e236c7ec221f..7035ffca020f 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4472,6 +4472,9 @@ const struct iommu_domain_ops intel_fs_paging_domain_ops = {
 	.iova_to_phys = intel_iommu_iova_to_phys,
 	.free = intel_iommu_domain_free,
 	.enforce_cache_coherency = intel_iommu_enforce_cache_coherency_fs,
+#ifdef CONFIG_LIVEUPDATE
+	.preserve = intel_iommu_domain_liveupdate_preserve,
+#endif
 };
 
 const struct iommu_domain_ops intel_ss_paging_domain_ops = {
@@ -4485,6 +4488,9 @@ const struct iommu_domain_ops intel_ss_paging_domain_ops = {
 	.iova_to_phys = intel_iommu_iova_to_phys,
 	.free = intel_iommu_domain_free,
 	.enforce_cache_coherency = intel_iommu_enforce_cache_coherency_ss,
+#ifdef CONFIG_LIVEUPDATE
+	.preserve = intel_iommu_domain_liveupdate_preserve,
+#endif
 };
 
 const struct iommu_ops intel_iommu_ops = {
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 3056583d7f56..6b69232efffd 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1345,6 +1345,10 @@ static inline int iopf_for_domain_replace(struct iommu_domain *new,
 	return 0;
 }
 
+#ifdef CONFIG_LIVEUPDATE
+int intel_iommu_domain_liveupdate_preserve(struct iommu_domain *domain);
+#endif
+
 #ifdef CONFIG_INTEL_IOMMU_SVM
 void intel_svm_check(struct intel_iommu *iommu);
 struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
diff --git a/drivers/iommu/intel/liveupdate.c b/drivers/iommu/intel/liveupdate.c
index d73d780d7e19..a15feef4d9ca 100644
--- a/drivers/iommu/intel/liveupdate.c
+++ b/drivers/iommu/intel/liveupdate.c
@@ -9,6 +9,14 @@
 #include <linux/liveupdate.h>
 #include <linux/module.h>
 
+#include "iommu.h"
+
+int intel_iommu_domain_liveupdate_preserve(struct iommu_domain *domain)
+{
+	pr_warn("Not implemented\n");
+	return 0;
+}
+
 static int intel_liveupdate_prepare(struct liveupdate_subsystem *handle, u64 *data)
 {
 	pr_warn("Not implemented\n");
-- 
2.51.0.536.g15c5d4f767-goog