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Message-ID: <20260203220948.2176157-10-skhawaja@google.com>
Date: Tue, 3 Feb 2026 22:09:43 +0000
From: Samiullah Khawaja <skhawaja@...gle.com>
To: David Woodhouse <dwmw2@...radead.org>, Lu Baolu <baolu.lu@...ux.intel.com>,
Joerg Roedel <joro@...tes.org>, Will Deacon <will@...nel.org>, Jason Gunthorpe <jgg@...pe.ca>
Cc: Samiullah Khawaja <skhawaja@...gle.com>, Robin Murphy <robin.murphy@....com>,
Kevin Tian <kevin.tian@...el.com>, Alex Williamson <alex@...zbot.org>, Shuah Khan <shuah@...nel.org>,
iommu@...ts.linux.dev, linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
Saeed Mahameed <saeedm@...dia.com>, Adithya Jayachandran <ajayachandra@...dia.com>,
Parav Pandit <parav@...dia.com>, Leon Romanovsky <leonro@...dia.com>, William Tu <witu@...dia.com>,
Pratyush Yadav <pratyush@...nel.org>, Pasha Tatashin <pasha.tatashin@...een.com>,
David Matlack <dmatlack@...gle.com>, Andrew Morton <akpm@...ux-foundation.org>,
Chris Li <chrisl@...nel.org>, Pranjal Shrivastava <praan@...gle.com>, Vipin Sharma <vipinsh@...gle.com>,
YiFei Zhu <zhuyifei@...gle.com>
Subject: [PATCH 09/14] iommu/vt-d: preserve PASID table of preserved device
In scalable mode the PASID table is used to fetch the io page tables.
Preserve and restore the PASID table of the preserved devices.
Signed-off-by: Samiullah Khawaja <skhawaja@...gle.com>
---
drivers/iommu/intel/iommu.c | 4 +-
drivers/iommu/intel/iommu.h | 5 ++
drivers/iommu/intel/liveupdate.c | 130 +++++++++++++++++++++++++++++++
drivers/iommu/intel/pasid.c | 7 +-
drivers/iommu/intel/pasid.h | 9 +++
include/linux/kho/abi/iommu.h | 8 ++
6 files changed, 160 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 83faad53f247..2d0dae57f5a2 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2944,8 +2944,10 @@ static bool __maybe_clean_unpreserved_context_entries(struct intel_iommu *iommu)
if (info->iommu != iommu)
continue;
- if (dev_iommu_preserved_state(&pdev->dev))
+ if (dev_iommu_preserved_state(&pdev->dev)) {
+ pasid_cleanup_preserved_table(&pdev->dev);
continue;
+ }
domain_context_clear(info);
}
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 057bd6035d85..d24d6aeaacc0 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1286,6 +1286,7 @@ int intel_iommu_preserve(struct iommu_device *iommu, struct iommu_ser *iommu_ser
void intel_iommu_unpreserve(struct iommu_device *iommu, struct iommu_ser *iommu_ser);
void intel_iommu_liveupdate_restore_root_table(struct intel_iommu *iommu,
struct iommu_ser *iommu_ser);
+void pasid_cleanup_preserved_table(struct device *dev);
#else
static inline int intel_iommu_preserve_device(struct device *dev, struct device_ser *device_ser)
{
@@ -1309,6 +1310,10 @@ static inline void intel_iommu_liveupdate_restore_root_table(struct intel_iommu
struct iommu_ser *iommu_ser)
{
}
+
+static inline void pasid_cleanup_preserved_table(struct device *dev)
+{
+}
#endif
#ifdef CONFIG_INTEL_IOMMU_SVM
diff --git a/drivers/iommu/intel/liveupdate.c b/drivers/iommu/intel/liveupdate.c
index 6dcb5783d1db..53bb5fe3a764 100644
--- a/drivers/iommu/intel/liveupdate.c
+++ b/drivers/iommu/intel/liveupdate.c
@@ -14,6 +14,7 @@
#include <linux/pci.h>
#include "iommu.h"
+#include "pasid.h"
#include "../iommu-pages.h"
static void unpreserve_iommu_context(struct intel_iommu *iommu, int end)
@@ -113,9 +114,89 @@ void intel_iommu_liveupdate_restore_root_table(struct intel_iommu *iommu,
iommu->reg_phys, iommu_ser->intel.root_table);
}
+enum pasid_lu_op {
+ PASID_LU_OP_PRESERVE = 1,
+ PASID_LU_OP_UNPRESERVE,
+ PASID_LU_OP_RESTORE,
+ PASID_LU_OP_FREE,
+};
+
+static int pasid_lu_do_op(void *table, enum pasid_lu_op op)
+{
+ int ret = 0;
+
+ switch (op) {
+ case PASID_LU_OP_PRESERVE:
+ ret = iommu_preserve_page(table);
+ break;
+ case PASID_LU_OP_UNPRESERVE:
+ iommu_unpreserve_page(table);
+ break;
+ case PASID_LU_OP_RESTORE:
+ iommu_restore_page(virt_to_phys(table));
+ break;
+ case PASID_LU_OP_FREE:
+ iommu_free_pages(table);
+ break;
+ }
+
+ return ret;
+}
+
+static int pasid_lu_handle_pd(struct pasid_dir_entry *dir, enum pasid_lu_op op)
+{
+ struct pasid_entry *table;
+ int ret;
+
+ /* Only preserve first table for NO_PASID. */
+ table = get_pasid_table_from_pde(&dir[0]);
+ if (!table)
+ return -EINVAL;
+
+ ret = pasid_lu_do_op(table, op);
+ if (ret)
+ return ret;
+
+ ret = pasid_lu_do_op(dir, op);
+ if (ret)
+ goto err;
+
+ return 0;
+err:
+ if (op == PASID_LU_OP_PRESERVE)
+ pasid_lu_do_op(table, PASID_LU_OP_UNPRESERVE);
+
+ return ret;
+}
+
+void pasid_cleanup_preserved_table(struct device *dev)
+{
+ struct pasid_table *pasid_table;
+ struct pasid_dir_entry *dir;
+ struct pasid_entry *table;
+
+ pasid_table = intel_pasid_get_table(dev);
+ if (!pasid_table)
+ return;
+
+ dir = pasid_table->table;
+ table = get_pasid_table_from_pde(&dir[0]);
+ if (!table)
+ return;
+
+ /* Cleanup everything except the first entry. */
+ memset(&table[1], 0, SZ_4K - sizeof(*table));
+ memset(&dir[1], 0, SZ_4K - sizeof(struct pasid_dir_entry));
+
+ clflush_cache_range(&table[0], SZ_4K);
+ clflush_cache_range(&dir[0], SZ_4K);
+}
+
int intel_iommu_preserve_device(struct device *dev, struct device_ser *device_ser)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct pasid_table *pasid_table;
+ int ret;
if (!dev_is_pci(dev))
return -EOPNOTSUPP;
@@ -124,11 +205,42 @@ int intel_iommu_preserve_device(struct device *dev, struct device_ser *device_se
return -EINVAL;
device_ser->domain_iommu_ser.did = domain_id_iommu(info->domain, info->iommu);
+
+ if (!sm_supported(info->iommu))
+ return 0;
+
+ pasid_table = intel_pasid_get_table(dev);
+ if (!pasid_table)
+ return -EINVAL;
+
+ ret = pasid_lu_handle_pd(pasid_table->table, PASID_LU_OP_PRESERVE);
+ if (ret)
+ return ret;
+
+ device_ser->intel.pasid_table = virt_to_phys(pasid_table->table);
+ device_ser->intel.max_pasid = pasid_table->max_pasid;
return 0;
}
void intel_iommu_unpreserve_device(struct device *dev, struct device_ser *device_ser)
{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct pasid_table *pasid_table;
+
+ if (!dev_is_pci(dev))
+ return;
+
+ if (!info)
+ return;
+
+ if (!sm_supported(info->iommu))
+ return;
+
+ pasid_table = intel_pasid_get_table(dev);
+ if (!pasid_table)
+ return;
+
+ pasid_lu_handle_pd(pasid_table->table, PASID_LU_OP_UNPRESERVE);
}
int intel_iommu_preserve(struct iommu_device *iommu_dev, struct iommu_ser *ser)
@@ -172,3 +284,21 @@ void intel_iommu_unpreserve(struct iommu_device *iommu_dev, struct iommu_ser *io
iommu_unpreserve_page(iommu->root_entry);
spin_unlock(&iommu->lock);
}
+
+void *intel_pasid_try_restore_table(struct device *dev, u64 max_pasid)
+{
+ struct device_ser *ser = dev_iommu_restored_state(dev);
+
+ if (!ser)
+ return NULL;
+
+ BUG_ON(pasid_lu_handle_pd(phys_to_virt(ser->intel.pasid_table),
+ PASID_LU_OP_RESTORE));
+ if (WARN_ON_ONCE(ser->intel.max_pasid != max_pasid)) {
+ pasid_lu_handle_pd(phys_to_virt(ser->intel.pasid_table),
+ PASID_LU_OP_FREE);
+ return NULL;
+ }
+
+ return phys_to_virt(ser->intel.pasid_table);
+}
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 3e2255057079..96b9daf9083d 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -60,8 +60,11 @@ int intel_pasid_alloc_table(struct device *dev)
size = max_pasid >> (PASID_PDE_SHIFT - 3);
order = size ? get_order(size) : 0;
- dir = iommu_alloc_pages_node_sz(info->iommu->node, GFP_KERNEL,
- 1 << (order + PAGE_SHIFT));
+
+ dir = intel_pasid_try_restore_table(dev, max_pasid);
+ if (!dir)
+ dir = iommu_alloc_pages_node_sz(info->iommu->node, GFP_KERNEL,
+ 1 << (order + PAGE_SHIFT));
if (!dir) {
kfree(pasid_table);
return -ENOMEM;
diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
index b4c85242dc79..e8a626c47daf 100644
--- a/drivers/iommu/intel/pasid.h
+++ b/drivers/iommu/intel/pasid.h
@@ -287,6 +287,15 @@ static inline void pasid_set_eafe(struct pasid_entry *pe)
extern unsigned int intel_pasid_max_id;
int intel_pasid_alloc_table(struct device *dev);
+#ifdef CONFIG_IOMMU_LIVEUPDATE
+void *intel_pasid_try_restore_table(struct device *dev, u64 max_pasid);
+#else
+static inline void *intel_pasid_try_restore_table(struct device *dev,
+ u64 max_pasid)
+{
+ return NULL;
+}
+#endif
void intel_pasid_free_table(struct device *dev);
struct pasid_table *intel_pasid_get_table(struct device *dev);
int intel_pasid_setup_first_level(struct intel_iommu *iommu, struct device *dev,
diff --git a/include/linux/kho/abi/iommu.h b/include/linux/kho/abi/iommu.h
index 8e1c05cfe7bb..111a46c31d92 100644
--- a/include/linux/kho/abi/iommu.h
+++ b/include/linux/kho/abi/iommu.h
@@ -50,6 +50,11 @@ struct device_domain_iommu_ser {
u64 iommu_phys;
} __packed;
+struct device_intel_ser {
+ u64 pasid_table;
+ u64 max_pasid;
+} __packed;
+
struct device_ser {
struct iommu_obj_ser obj;
u64 token;
@@ -57,6 +62,9 @@ struct device_ser {
u32 pci_domain;
struct device_domain_iommu_ser domain_iommu_ser;
enum iommu_lu_type type;
+ union {
+ struct device_intel_ser intel;
+ };
} __packed;
struct iommu_intel_ser {
--
2.53.0.rc2.204.g2597b5adb4-goog
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